state of environment report - kerala 2007 vol

Transcription

STATE OF ENVIRONMENT REPORT KERALA 2007
VOL - I
Land Environment, Wetlands of Kerala
& Environmental Health
KERALA STATE COUNCIL FOR
SCIENCE, TECHNOLOGY AND ENVIRONMENT
i
STATE OF THE ENVIRONMENT REPORT OF KERALA 2007
VOLUME - I
© 2007 KSCSTE, Government of Kerala
Project Team and Editorial Board
Editor-in-chief
Dr.E.P.Yesodharan
Executive Vice President
Executive Editor and Co-ordinator
Dr.Kamalakshan Kokkal
Principal Scientific Officer
Editor
Dr.P.Harinarayanan
Scientific Officer
Technical Officer
Smt. J. Usha Kumari
No. of copies:500
First published:June 2007
Published by:
Kerala State Council for Science,Technology and Environment
Sasthra Bhavan,Pattom
Thiruvananthapuram-695 004
Kerala State,India
Ph : (0471)2543701-05(five lines); Fax:+91-471-2540085
E-mail:info@kscste.org
NOT FOR SALE
ISBN 81-863666-59-8
Cover - Photos & Design : A.Bijukumar & Creative Graphics
Type Setting and Printing at:
S B Press (P) Ltd, Thiruvananthapuram 695001, Ph : 2471904, 2478013
ii
KERALA RAJ BHAVAN
THIRUVANANTHAPURAM
PIN : 695 099
29 May 2007
MESSAGE
I am happy to know that the Kerala State Council for Science,
Technology and Environment is bringing out the State of Environment
Report on Land Environment, Wetlands of Kerala and Environment &
Health as a part of a long-term perspective plan for the state.
I am glad to note, the report would provide authentic information
on the topics, and would help to protect the environment by facilitating
Government and Non-Governmental agencies in the field to work in
close co-ordination.
I wish the venture all success.
Sd [R.L. Bhatia]
iii
iv
PHONE
V.S.ACHUTHANANDAN
CHIEF MINISTER OF KERALA
{
OFFICE : 2333812
2333682
FAX
: 0471-2333489
19-05-2007
MESSAGE
It is a matter of immense pleasure to know that the Kerala State
Council for Science Technology and Environment is publishing the State
of Environment Report on Land Environment, Wetlands of Kerala and
Environment & Health. The topics selected are very relevant for the
State. I am sure that the report will provide authentic information to
the Governmental and Non-governmental agencies and facilitate long
term planning of strategies for the development of the State.
I congratulate the efforts of the officers and staff of the KSCSTE
for bringing out the report and hope it will be useful for all concerned.
V.S.Achuthanandan
v
vi
FOREWORD
A healthy Environment is essential for the survival and growth of all living things. The
growing concern on environment has prompted the world to think in a new direction and
address related issues in a more scientific manner. Sustainable development of any State
rests on three pillars: economic growth, social progress and protection of the environment.
Conservation of environment has become a challenge due to increased population and
consequent pressure on the natural resources. As life-sustaining systems come under
growing pressure from human activity, it is absolutely essential, that everybody should
contribute for reducing the causes of global warming, pollution, fresh water scarcity and
loss of biodiversity. The future of mankind is inevitably linked to that of plants, animals and
ecosystems.
The Kerala State Council for Science, Technology and Environment has brought out this
State of Environment Report in an effort to achieve a participatory and scientifically rigorous
SoE reporting system in the country. This is expected to initiate an informed debate and
elicit viable solutions, thereby assisting in essential policy and strategy formulation. A
number of organizations were associated in gathering the information related to land
environment, wetlands of Kerala and environment and health for the preparation of this
report.
The Council had earlier published the State of Environment Report during 2005 and this
report was on the topics that were not covered in the first Phase. The report is expected
to sensitize the citizens, the authorities and other agencies and stakeholders about the
threat to the environment and provide a basis for preparing a long term strategy for improving
the quality of our environment.
The Ministry of Environment and Forests, Government of India has given the necessary
financial assistance for the project. The Energy Research Institute (TERI), which is also the
National Host Institute rendered technical support and necessary guidance. The continuous
support of Sri. Harpreeth Singh, Associate Fellow TERI deserves special appreciation.
vii
I acknowledge the services provided by Dr. K.P. Thrivikaramji, Rtd. Professor of Geology,
Kerala University, Dr. C.R. Soman, Director Health Action for People and Dr. C. Bhaskaran,
Professor, Kerala Agriculture University for their valuable contributions as members of
evaluation committee. The contributions made by the Scientists of CESS, CWRDM, KFRI,
IIITKM, CED, faculties of CUSAT, Kerala University, Calicut University and Kerala
Agricultural University for bringing out this report deserve special appreciation.
The Kerala State Council for Science, Technology and Environment, as the State Host
Institute, has undertaken the project with the active support of its technical and
administrative staff. I wish to record my appreciation for the sincere efforts of the coordinator of the project Dr. Kamalakshan Kokkal, Principal Scientific Officer, and Dr. P.
Harinarayanan, Scientific Officer of the Council who were instrumental in bringing out this
report.
I hope the report will be useful for the planners, decision makers and public at large and
help the Government in the long term planning for sustainable development.
Dr. E.P. Yesodharan
Executive Vice President
viii
PREFACE
It is to be remembered that the Rio de Janeiro conference held in 1992 adopted Agenda
21, a global plan of action to confront the pressing needs of the world and to prepare for
the challenges of the next century in order to attain the long-term goal of sustainable
development. The above objective is to be achieved with the active involvement of various
stake holders. In this connection, the attempt of the Kerala State Council for Science,
Technology and Environment (KSCSTE) to bring out a comprehensive State of Environment
Report for Kerala is further fulfilled with the publications of the reports on the following:
Volume I - Land Environment, Wetlands of Kerala and Environment and Health, Volume II Natural Hazards, Volume III - Corporate Environment Management and Volume IV Environmental Indicators. The reports are prepared by working groups consisting of experts
belong to different scientific/academic institutions under the overall co-ordination of KSCSTE.
A number of discussions/consultative processes and workshops by involving different working
groups were held for developing the report and made necessary mid term corrections. As
far as possible DPSIR (D= driving forces of environmental change, P= pressure on the
environment, S= state of the environment, I= impacts and R= response) format which is
based on cause-effect relationship between interacting components of the social, economic
and environmental systems has been adopted for the preparation of the report. In these
reports attempt has been made to draw a baseline based on secondary data. These reports
will be useful for creating environmental awareness and also to provide referances to all
kinds of efforts for improving environment leading to sustainable development.
I am deeply indebted to Dr E P Yesodharan, Executive Vice President of KSCSTE who
took strong interest in the project and rendered active co-operation necessary for the
successful completion of the project. The perpetual encouragements by Dr M S Valiathan
and Dr A E Muthunayagam, former Executive Vice Presidents and Dr K R S Krishnan former
Member Secretary of the Council are deeply acknowledged. The support of Shri K
Unnikrishnan Unnithan former Member Secretary incharge of the KSCSTE is also
acknowledged.
The active support and encouragement provided by Sri Harpreet Singh Kandra, Associate
Fellow TERI to develop necessary strategy for preparing the reports is deeply acknowledged.
ix
My gratitude are also due to the Vice-chancellors of Cochin University, Kerala University,
Calicut University, Kerala Agricultural University, Chairman and Member Secretary KSPCB
and the Directors of CESS, CWRDM, KFRI, IIITKM, Kerala Landuse Board and Centre for
Environment and Development for permitting their experts to involve in the novel attempt.
The scientists belong to different working groups provided substantial contributions for
preparing the report which are greatly acknowledged. The active support of Prof (Rtd) K P
Thrivikramji, Prof (Rtd) C R Soman and Prof C. Bhaskaran, members of the evaluation
committee are deeply appreciated. I am also grateful to the help rendered by Dr P
Harinarayanan, Scientific Officer, scientific and administrative colleagues in the Council
for providing necessary support for completing this venture. The valuable suggestions and
informations for further improving the quality of the reports are most welcome.
The support provided by the Ministry of Environment and Forests, Government of India
and The Energy Research Institute (TERI), New Delhi is deeply acknowledged.
I do hope that these documents would serve as a useful input to the pursuit of sustainable
development for the state.
25th May, 2007
Thiruvananthapuram
x
Dr Kamalakshan Kokkal
Principal Scientific Officer
EVALUATION COMMITTEE
Dr. K.P. Thrivikramji
Rtd. Prof. Dept. of Geology, Kerala University
Dr. C.R.Soman
Director Health Action for people,
Thiruvananthapuram
Dr. C. Bhaskaran
Prof. Dept. of Agricultural Extension, College of
Agriculture, K.A.U, Vellayani, Thiruvananthapuram
Sri. Harpreet Singh Kandra
Associate Fellow, TERI, New Delhi
LIST OF CONTRIBUTORS
LAND ENVIRONMENT
Dr. R. Ajaykumar Varma
Nodal Officer
Centre for Earth Science Studies
Thiruvananthapuram
Dr. Abdul Samad
Kerala State Land Use Board
Thiruvananthapuram
Dr. R. Anilan
Western Ghat Cell, State Planning Board
Thiruvananthapuram
Dr. D.S. Suresh Babu
Thiruvananthapuram
Dr. Sudharmai Devi
College of Agriculture, Kerala Agricultural
University, Vellayani, Thiruvananthapuram
xi
Dr. Thomas P. Thomas
Kerala Forest Research Institute, Thrissur
Dr. M.S. Bindu
Department of Environmental Sciences
Kerala University, Thiruvananthapuram
WETLANDS OF KERALA
Dr. Babu Ambat
Nodal Officer
Centre for Environment and Development
Thiruvananthapuram
Dr. P.V. Madhusoodhanan
Department of Botany, University of Calicut
Dr. A.S.K. Nair
Thiruvananthapuram
Dr. P.S. Harikumar
Centre for Water Resources Development
and Management, Kozhikode
Dr. T. Sabu
Centre for Environment and Development
Thiruvananthapuram
ENVIRONMENT AND HEALTH
Dr. Shailaja Tetali
IIITMK, Technopark, Thiruvananthapuram
Dr. Lincoln P. Choudhury
IIITMK, Technopark, Thiruvananthapuram
xii
CONTENTS
List of Contributors
List of Tables
List of Figures
Acknowledgement
Executive Summary
Chapter 1
1.1
1.2.
LAND ENVIRONMENT
Introduction
1
1.1.1
Physiography
1
1.1.2
Geology
4
1.1.3
Drainage
6
1.1.4
Terrain Units
6
1.1.5
Soil
8
1.1.6
Mineral resources
12
1.1.7
Landuse
12
1.1.8
Land capability
12
Environmental Issues
15
1.2.1
Landuse change
16
1.2.1.1
Driving force
16
1.2.1.2
Pressure
18
1.2.1.3
State
22
xiii
1.2.2
1.2.3
1.2.4
1.2.5
Chapter 2
Impact
25
1.2.1.5
Response
27
Mining
28
1.2.2.1
Driving force
29
1.2.2.2
Pressure
31
1.2.2.3
State
32
1.2.2.4
Impact
37
1.2.2.5
Response
39
Soil Erosion
40
1.2.3.1
Driving force
41
1.2.3.2
Pressure
44
1.2.3.3
State
44
1.2.3.4
Impact
47
1.2.3.5
Response
49
Soil Quality Deterioration
50
1.2.4.1
Driving force
51
1.2.4.2
Pressure
51
1.2.4.3
State
54
1.2.4.4
Impact
71
1.2.4.5
Response
73
Recommendations
75
WETLANDS OF KERALA
2.1
xiv
1.2.1.4
Introduction
85
2.1.1
Background
85
2.1.2
Definition of wetlands
86
2.1.3
Significance of wetlands
87
2.1.4
Origin and classification of wetlands
88
2.1.5
Status of wetlands in India
92
2.1.6
Wetlands of Kerala : present
scenario
93
2.1.7
2.2
2.3
2.4
Chapter 3
Institutional structure, policies
and legislation
100
Major Management Issues
105
2.2.1
Driving forces
105
2.2.2
Pressures
112
2.2.3
State of environment
117
2.2.4
Impacts on population, economy,
ecosystem
133
2.2.5
Responses
136
Status of Environment of Selected Wetlands
141
2.3.1
Vembanad - kol wetland
141
2.3.2
Ashtamudi wetland
157
2.3.3
Sasthamkotta lake
163
2.3.4
Periyar reservoir
170
2.3.5
Kadalundi estuary
177
Conclusions and Recommendations
182
2.4.1
Conclusions
182
2.4.2
Recommendations
184
3.1
3.2
Introduction
194
3.1.1
Scope
194
3.1.2
Approach and methodology
195
Overview of the Current Institutional
systems in Place
195
3.2.1
195
Overview of current policy
3.3
Water Borne Diseases
196
3.4
DPSIR framework
200
3.4.1
Driving force
200
3.4.2
Pressure
201
3.4.3
State
202
3.4.4
Impact
202
xv
3.5
3.6
3.7
Critical Issues
202
3.5.1
Access to adequate quantity of
water of reasonable quality
203
3.5.2
Access to sanitation
206
3.5.3
Surveillance
207
3.5.4
Chemical contaminants
207
Disease Burden
213
3.6.1
Leptospirosis
216
3.6.2
Cholera
218
3.6.3
Mineral water industry
219
Response
220
3.7.1
Institutional arrangements
220
3.7.2
Infrastructure and Legislative
measures
221
3.7.3
Research studies undertaken and
projects initiated
222
3.7.4
Policy and practice
222
3.8
Limitation of Data
222
3.9
Conclusions
223
3.10
Recommendations
223
References
224
Case study of mosquito borne diseases in Kerala
xvi
LIST OF TABLES
Chapter 1
LAND ENVIRONMENT
1.1
Physiographic units, altitudes and areas
3
1.2
Terrain units and area
8
1.3a
Legend of Figure 5.
10
1.3b
Legend of Figure 5.
11
1.4
Mineral reserves (2000-01)
14
1.5
Changes in crop area and production, Kerala
1961-62 & 2005-06
21
1.6
Level of conversion of paddy land in Wynad
21
1.7
Change in landuse pattern
22
1.8
Consumption of Fertilizer nutrients (tons) in Kerala
25
1.9
Generalized rate of soil loss according to landuse
27
1.10
Total area covered by mining lease
29
1.11
Production and sale of mineral sand in
Kerala during 1999-2000
30
1.12
Details of river sand mining in certain rivers, Kerala
34
1.13
Lime shell extraction from Vembanad Lake
36
1.14
Slope class distribution, Kerala
41
1.15
Erodability of soils, Kerala
43
1.16
Extent of soil erosion (% of the TGA)
44
1.17
Infiltration rate of certain soils, Kerala
45
1.18
Status of land degradation, Kerala (1985 & 1994)
46
1.19
Category-wise land degradation,
Kerala (2003)
46
xvii
Chapter 2
xviii
1.20
Various types of land degradation
and Wastelands, Kerala
46
1.21
Types and extent of waste lands,
Kerala (After KSLUB, 2005)
48
1.22
Sedimentation rate in selected reservoirs,
Kerala
49
1.23
Domestic solid waste generation in 2001,
Kerala
52
1.24
Texture and structure of the different
soil types of Kerala
56
1.25
Bulk density and WHC of Kerala soils
57
1.26
Effective Soil Depth and Water Table Depth
58
1.27
Values of pH and EC of Kerala soils
61
1.28
Characterization of acidity in major
wetlands of Kerala
62
1.29
Available major nutrient status
(kg ha-1) of Kerala
65
1.30
Available major nutrient status
(kg ha-1) of wetland soils of Kerala
66
1.31
Available secondary nutrient status
(mg kg-1) of wetland soils of Kerala
66
1.32
Available micro nutrient status
(mg kg-1) of wetland soils of Kerala
67
1.33
Bacterial population (106 g-1 of dry soil)
in different locations and crops
68
1.34
Fungal population (106 g-1 of dry soil)
in different locations and crops
68
1.35
Population of Actinomycetes (106 g-1 of dry soil)
in different
68
1.36
Bacterial activity in the Kari soils of Kuttanad
68
1.37
Enzyme activity in soils of different agro ecosystems
69
WETLANDS OF KERALA
2.1
Classification Scheme for Wetlands of Kerala
91
2.2
Wetlands in India designated as Ramsar Sites
92
2.3
Area under wetlands of Kerala
93
2.4
Backwaters/ Estuaries of Kerala
95
Chapter 3
2.5
Freshwater Lakes of Kerala
96
2.6
Reservoirs of Kerala
96
2.7
Ponds, tanks and other small
wetlands of Kerala
97
2.8
Mangrove Ecosystems, Kerala
98
2.9
Unique Wetland Ecosystems of Kerala
99
2.10
Biodiversity of Vembanad Wetland
145
2.11
Water quality, Vembanad - kol wetlands
153
2.12
Depth ranges in various sectors,
Vembanad Estuary
155
2.13
Biodiversity of the Ashtamudi Wetland
159
2.14
Water Quality, Ashtamudi wetland
162
2.15
Biodiversity of the Sasthamkotta Lake
166
2.16
Water Quality, Sasthamkotta lake
168
2.17
Biodiversity of PTR
172
2.18
Water Quality, Periyar lake
175
2.19
Tidal Fluctuation of Kadalundi Estuary
178
2.20
Biodiversity of Kadalundi Estuary
179
2.21
Water quality, Kadalundi estuary
181
3.1
Information flows in the State, with respect
to monitoring of water quality
196
3.2
Water borne diseases
199
3.3
Environmental agents
202
3.4
Drinking water quality standards as recommended
by WHO and BIS
204
3.5
Source of chemical contaminants
208
3.6
Trend and present endemicity of the problem
India and Kerala 2002
235
3.7
Chikungunya Fever Situation in India and
Kerala during 2006 Table
240
xix
xx
LIST OF FIGURES
Chapter 1
LAND ENVIRONMENT
1.1
Physiographic map of Kerala
2
1.2
A profile across central part of Kerala
3
1.3
Geologic map of Kerala
5
1.4
Drainage map of Kerala
7
1.5
Distribution of major soils in Kerala
9
1.6
Mineral map of Kerala
13
1.7
Landuse pattern, Kerala
14
1.8
Area under different Land Capability Classes
15
1.9
Characteristics of population growth in Kerala
18
1.10
Landuse/cover change in a high range micro
watershed (Mankulam) from 1976 to 2003
19
1.11
Details of rice cultivation in Kerala
20
1.12
Crop distribution, Kerala
23
1.13
Distribution of plantation crops
24
1.14
Locations of quarries in Thiruvananthapuram District
35
1.15
Altitudinal characteristics of Central Kerala Region
42
1.16
Distribution of different types of waste land
47
1.17
Compliance status of waste management
practices, Kerala
55
1.18
Components of soil
59
1.19
Organic carbon content (%) of soils, Kerala
60
1.20
CEC (c mol kg-1) of Kerala soils
64
xxi
Chapter 2
xxii
WETLANDS OF KERALA
2.1
Location Map of selected wetlands of Kerala
94
2.2
DPSIR framework for wetlands of Kerala
106
2.3
Wetland reclamation for housing
107
2.4
Brahminy Kite - found killed in a wetland
109
2.5
Sand Mining
110
2.6
Coconut husk retting
112
2.7
Municipal solid waste
113
2.8
Plastic wastes in canals of Kochi
114
2.9
Solid wastes disposed in bundles
114
2.10
Aquatic weeds
117
2.11
Eichhornia crassipes
119
2.12
Eutrophication process
119
2.13
Nymphoides indicus
120
2.14
Mangrove forest at Kannur
128
2.15
Acanthus ilicifolius
128
2.16
Calophyllum inophyllum
129
2.17
Myristica swamps
130
2.18
Water Birds
132
2.19
Blocked water way
135
2.20
Mangrove afforestation, Kalliasseri, Kannur
140
2.21
Map of Vembanad wetland - Kumarakom
area and its Environs
142
2.22
Vembanad Wetland north of Kuttand upto
Puthuvypin
143
2.23
Thottapally Spillway
149
2.24
Thanneermukkom barrier
150
2.25
Point and Diffuse Sources of Pollution
151
2.26
Concentration of Phosphorous in Vembanad Lake
154
2.27
Ashtamudi Wetland and Environs
158
2.28
Sasthamkotta Lake and Environs
165
2.29
Periyar Reservoir and Environs
171
2.30
Kadalundi Wetland and Environs
177
Chapter 3
3.1
Flow of information with respect to diseases
197
3.2
Humans and their environment
200
3.3
Routes of exposure
201
3.4
Comparison of access to safe drinking water
in households in India and Kerala
204
3.5
Chemicals affecting water in Kerala
208
3.6
Number of habitations affected by fluoride in water
209
3.7
Number of habitations affected by iron in water
211
3.8
Number of habitations affected by nitrate in water
212
3.9
Severity of adverse effects on populations
213
3.10
Diarrhoeal diseases in Kerala- district wise
214
3.11
Food and water borne diseases in Kerala in 2005
215
3.12
Seasonal variation of diarrhoeal diseases in
Kerala for '04-'05
215
3.13
Reported cases of leptospirosis in Kerala in
2003-05
217
3.14
Seasonal pattern of leptospirosis in Kerala
during 2004-05
218
3.15
Reported cases of Cholera in Kerala-2002
219
3.16
Relationship between water supply and
diarrhoeal cases
220
3.6
Mosquito borne diseases and Human health
in DPSIR framework
229
3.7
District wise reported malaria cases in
Kerala 2004-2005
232
3.8
Reported JE cases in Kerala in comparison to India
234
3.9
Micro filarial rate in Calicut
235
3.10
Reported Dengue cases in India and Kerala
2005 to 2006
238
xxiii
xxiv
ACKNOWLEDGEMENT
KSCSTE gratefully acknowledge the advice and support rendered by the following personnel and organizations in the preparation of this report
•
Secretary, Ministry of Environment and Forests , Government of India
•
Director General, TERI, New Delhi
•
Secretary, Environment Department, Government of Kerala
•
Dr. V.S. Valiyathan, Former-Executive Vice President, KSCSTE
•
Dr. A.E. Muthunayagam, Former-Executive Vice President, KSCSTE
•
Dr. K.R.S. Krishnan, Former Director STED & Member Secretary, KSCSTE
•
Sri. Unnikrishnan Unnithan, Former Member Secretary- in charge, KSCSTE
•
Secretary, Planning and Economic Affairs, State Planning Board,
Thiruvananthapuram
•
Director, Centre for Earth Science Studies, Thiruvananthapuram
•
Director, Centre for Water Resources Development and Management,
Kozhikode
•
Director, Kerala Forest Research Institute, Peechi, Thrissur
•
Vice Chancellor, Kerala University
•
Vice Chancellor, Calicut University
•
Vice Chancellor, Cochin University of Science and Technology
•
Vice Chancellor, Kerala Agriculture University
xxv
•
Director, IIITKM, Thiruvananthapuram
•
Director, Kerala Landuse Board, Thiruvananthapuram
•
Director, Centre for Environment and Development
•
Prof. K P Thriviramji (Retd) Dept of Geology, Kerala University
•
Dr. C.R. Soman, Director, Health Action for People, Thiruvananthapuram
•
Dr. C. Bhaskaran, Professor, Dept. of Agricultural Extension, College of
Agriculture, Kerala Agriculture University
•
Dr Harpreet Singh Kandra, `Associate Fellow, CES, TERI, New Delhi
•
Dr. C.S.P. Iyer, Former Consultant, KSCSTE
xxvi
EXECUTIVE SUMMARY
A. Land Environment
Kerala is endowed with a combination of distinct altitudinal variations, three natural regions namely, lowlands, midland, highlands and four major rock formations namely,
crystallines, sedimentaries, laterites and recent and sub recent sediments. The state is
gifted with vibrant climate, vivacious hydrology, distinct geological domains and terrains,
different mineral deposits, copious groundwater resources, ten soil types and distinct agro
climatic zones and multitudes of lively micro ecosystems. The environment is conducive to
varying crop types, such as, coconut and rice in the sultry lowlands, rice, tapioca, banana,
arecanut, coconut, pepper, cashew and rubber in hot humid midlands and tea, coffee and
cardamom in the cool subtropic highlands. Agriculture is practiced in over 55% of the
geographical area. The micro ecosystems are such that the valleys with near waterlogged
conditions for most part of the year are seen juxtaposed with dry hilltops decked with
densely canopied trees.
The increased pressure on land for more resources and accelerated human interventions in the form of mining, quarrying, filling of low lands along with all the ingredients
like high rainfall, undulating topography etc has led to significant land modifications influencing the biophysical system and adversely affecting the ecological security and environmental stability. The major environmental issues confronting land environment are landuse
change, mining, soil erosion and soil quality deterioration. These issues are analyzed in
terms of their driving force, pressure, present status, and impact.
Landuse changes are manifested, generally, as change in cropping pattern, quarrying, slope modification, soil excavation, conversion of paddy lands and swampy areas and
filling of wetlands etc. Such changes affect the environment adversely by way of intense
soil erosion, water logging, water scarcity, mono cropping and loss of biodiversity. The
terrain modifications, generally effected as a prelude to landuse changes, at times, lead to
catastrophic incidences of landslides and increased recurrence of earth tremors, land subsidence etc. Population growth, migration, urbanization, industrialization and globalization
are the major factors that led to significant landuse change in the State. The landuse
xxvii
changes over the years were instrumental in changing the landscape ecology, which had
far-reaching environmental consequences. The conservation, development and management of land resources based on agro-ecological and social parameters are vital and it
requires resource based landuse planning for agricultural and non-agricultural uses with
special consideration for fragile ecosystems such as paddy fields, high lands etc.
Mining of natural resources involves extreme disturbance to biological life systems, in general, and violation of the rights of local communities in particular. The major
mining activity in the State is confined to the beach placers and china clay deposits. There
are also unorganized mining activities, especially with respect to tile and brick clay, alluvial
sands, crystalline rocks, soils etc. Many of the mineral occurrences are in very fragile
physical, biological and social environments and therefore, the pressure exerted and the
impacts are high in terms of magnitude and intensity and mostly permanent in nature.
Most of the existing mineral based industries today are confined to the extraction and sale
of raw minerals without optimal value addition. It is high time to concentrate on indigenous
beneficiation of minerals to develop high quality end products.
Soil erosion results not only in the loss of soil materials, but also in the loss of soil
nutrients, and soil bio-resources. Loss of soil causes decrease of soil volume over the
bedrock that is available for storage of water and hence will reduce effective water availability for growth of plants as well as recharge of ground water. Soil flora and fauna that is
abundant in the surface soil and responsible for the fertility and productivity of soil, also
get washed off along with top soil. In Kerala, the soil erosion is mainly due to flowing water
and is catalyzed by peculiar land form, soil types, climate and landuse. The quantum of
eroded soil or debris gets transported over land or deposited in ponds, rivers, reservoirs
and lakes or washed down to the sea. There is continued effort on effective implementation of watershed based development programmes with thrust on agronomic measures.
Intensive cultivation, often with incorrect crop and soil management practices,
give rise to heavy loss in soil quality. The neglect of organic or green manure application,
excessive or imbalanced application of chemical fertilizers, indiscriminate use of insecticides, fungicides, herbicides etc gave rise to alterations in soil structure, which in turn led
to changes in all other soil quality attributes. The poor performance in industrial and municipal waste management further aggravated the scenario. The enhanced land and water
pollution has its manifestations not only in agricultural productivity but also in increasing
disease burden. The drive for organic cultivation and effective pollution control is yet to
catch up with the necessity.
The land is mostly subjected to undesirable practices and hence subjected to serious degradation in Kerala. In order to over come this and to have a comprehensive action
plan for conservation and management of limited land that the State has, it is appropriate
to evolve a detailed Land Use Policy, integrated action plans and statutory regulations and
appropriate institutional mechanisms for their effective implementation. Preventive and
curative measures against pollution and contamination of soil and land may receive high
xxviii
priority for years to come, and technological measures to prevent the ill effects on human
health will get priority in short term.
B. Wetlands of Kerala
Wetlands can be defined as areas transitional between permanently flooded
deepwater environments and well drained uplands that contribute a wide array of biological, social and economic benefits. Kerala is well known for its wetlands and these wetlands provide livelihood to the residents in the area in the forms of agricultural produce,
fish, fuel, fiber, fodder, and a host of other day-to-day necessities. As much as one fifth of
the State's total landmass is wetlands which include a vast network of backwaters, lagoons, Mangrove ecosystems, natural lakes, ponds, tanks, rivers and canals, manmade
reservoirs, ponds etc. The Ministry of Environment & Forests (MoEF), Government of India, broadly divided wetlands of India, into Inland wetlands and Coastal wetlands and each
class is further divided into different types. Geomorphologically, the wetlands in Kerala
may be divided among five major systems at the broadest level as marine, estuarine,
riverine, and lacustrine and palustrine. Kerala has some unique types of wetland ecosystems like the marshy and water-logged areas and vast paddy cultivating areas associated
with the backwaters and the Myristica Swamps of Western Ghat forests. Five wetlands
of Kerala - Vembanad-kol, Ashtamudi and Samsthamkotta, (Ramsar sites); Kottuli and
Kadalundi were identified by MoEF for implementing management action plan under National Wetland Conservation Programme.
The wetlands in Kerala are currently subjected to acute pressure owing to rapid
developmental activities and indiscriminate utilization of land and water. Infrastructure
development in the form of roads, railways, and other lines of communication fragmented
the continuity of the wetlands, and destroyed extensive tracts of coastal vegetation thereby
upsetting the entire complex ecology; rapid urbanisation encroached into the rich and luxuriant mangrove forests, while industrial development not only caused pollution but prevented any regeneration possibilities as well; modern shrimp farms brought in the final
onslaught - the irreversible destruction of wetlands. The major issues facing the wetlands
of Kerala are mainly related to pollution, eutrophication, encroachment, reclamation, mining and biodiversity loss.
The major driving forces elucidated are: (i) population/households growth and urbanization, (ii) industries (iii) infrastructure (iv) agriculture (v) aquaculture (vi) fishing (vii)
poaching (viii) mining (ix) deforestation (x) services (xi) water transport and xii) tourism.
The major pressures identified are from (i) industrial effluents (ii) retting of coconut husk
(iii) leachates from agricultural fields (iv) waste disposal (v) petroleum hydrocarbons (vi)
landuse changes (vii) hydraulic interventions (viii) overexploitation of resources and (ix)
weed infestation.
The state of environment of the wetlands of Kerala is discussed under following,
(i) pollution and eutrophication (ii) encroachment, reclamation and mining and (iii) biodiversity
loss. Wetlands under extreme threat are more in Kerala than in any other State. Studies
xxix
carried out in recent years have pointed out the unfavorable changes taking place in the
physical, chemical, biological and geological environment of the wetlands. Most of the
pollution sources are man made and include industrial effluents, sewage and faecal disposal, pesticides and chemical fertilisers, retting of coconut husks, slaughter house waste,
domestic waste, etc. Shrinkage of 73% of the backwaters of Kerala was reported even in
1989-90. The status of over 90 species of fishes and 16 species of birds found in the
wetlands of Kerala has been red listed by the IUCN. There are clear evidences to show that
very rich mangrove vegetation existed along the coastal tracts of Kerala and was once
supported about 700 sq km of mangrove areas. The mangroves exist now in less than 17
sq km are only the relics of the past.
The major impacts on population, economy and ecosystem described are: (i) diminution of bioresources (ii) species loss (iii) food toxicity (iv) waterborne and zoonotic diseases (v) obstruction to navigation (vi) decrease in agriculture production and productivity
(vii) scarcity of potable water (viii) flood and drought and (ix) aesthetic value depletion.
The responses to the present state of wetlands and impacts include: (i) the most
recent legal and institutional review and action by the authorities, upon ratification of the
Ramsar Convention (ii) the research and development initiatives taken up by both the Government and Non Government agencies and (iii) a good number of programmes taken up by
many people's movements all over the State for the protection of the wetlands and its
resources.
The status of five selected wetlands in Kerala are analysed in DPSIR framework.
Three of them viz., Vembanad - Kol wetland, Ashtamudi wetland and Sasthamkotta Lake
are Ramsar Sites. The Periyar Lake is in the Periyar Tiger Reserve, one of the major Protected Area in the State and Kadalundi Estuary (selected under national conservation plan),
which holds one of the best Mangrove area are the other two wetlands described.
As a valuable natural resource, wetlands are to be conserved under the policy
resolution of sustainable development and environmental protection. In India there is no
single agency to look after the conservation and wise use of wetlands and is vested in
several agencies like the MoEF, Department of Fisheries, Ministry of Agriculture, Ministry
of Water Resources, Ministry of Surface Transport etc. Since land is a State subject,
various State government agencies are also involved in making decisions on wetlands.
Under the Wildlife Protection Act (WPA) and other central acts, like the Indian Forest Act,
wetlands are not even defined as a separate category of ecologically important areas,
instead generally form part of protected areas. The existing laws needs to be amended to
incorporate a broad inclusive definition of wetlands (specifically in the WPA), to facilitate
and make it legally binding for wetland managers to draw up wetland conservation plans.
There is also an urgent need for enactment of policy procedure for the conservation and
management of wetlands in the State. Legal actions and policy decisions to prevent wetland conversion, reclamation, pollution etc are required. Keeping biodiversity under public
good has been cited as one of the reasons for the steady degradation of wetlands. Ensuring
community participation in planning and decision making at all levels and local vigilantism
xxx
with the involvement of Local Government Institutions, and NGOs may help in the effective implementation of the Environmental Management Plan (EMP).
In spite of the fairly large volume of work carried out on the various aspects of
wetlands of Kerala, there is no public repository of data and summary embodied in the
documents. Formulation of management plans, need maps of the scale of at least 1:25,000
scales or even lower are not available now. Aquatic ecosystems and wetlands are usually
considered as wastelands and are being reclaimed for various developmental needs, forcing several taxa, (which otherwise would have a great potential value in medicine and other
industrial uses), to the verge of extinction. There is a great need for inventorying the
aquatic and wetland taxa, especially in the face of the rampant habitat destruction that is
taking place. The degree of endemism in wetland areas is barely touched upon. So also
there are no accounts on the vulnerability of species and the status of traditional knowledge system associated with wetland resources. Technological interventions are also required at times for the wise use of the wetlands. This may include improvement of water
quality, ensuring free flow of tidal currents for enhancing the quality of aquatic life and
careful and scientific scrutiny of development projects prior to design and budgeting process to avoid conflict among stakeholders.
C. Environment & Health : Water
The environment and health deals with issues with special reference to water and
vector borne diseases in Kerala. Attempt has been made to overview the current institutional systems in place and current policies of the Government. Water borne diseases
from faecal contamination are one of the biggest public health risks. High population density, rapid urbanization and limited awareness of hygiene, disease prevention and spread
are identified as important driving forces. The pressure extended on the environment consists of environmental agents like Chemical (fluoride), Biological (Bacteria, Virus), mosquito's,
increased human demand and unplanned use of limited resources. The limited access to
safe drinking water and sanitation is the state. The impact on human health also identified.
The responses like ENVIS, Swajal Dhara, total sanitation campaign, integrated disease
surveillance project, National Vector Borne disease control programme, National Water
Policy, Population base surveillance system for water contaminants, logistic steps are
being implemented and the problems also identified with necessary recommendations for
improvement.
xxxi
xxxii
State of the Environment Report - 2007 - Vol. I
LAND ENVIRONMENT
1.1. INTRODUCTION
Kerala is endowed with a combination of distinct altitudinal variations resulting from the
rise of the land mass from 5 meters below sea level in the west to the soaring heights of
2695 meters in the east within the short span of 120 km. The small expanse of land with
an area of 38,863 km2 has a base length of 560 km along the coast and width ranging from
11 km to 124 km. Physiographically, the terrain has three natural regions namely, lowlands,
midland, highlands (Figure 1.1). Geologically, Kerala is occupied by four major rock formations
namely, crystalline rocks of Precambrian age, sedimentary rocks of Tertiary confined to
Neogene period, laterites capping the crystalline and sedimentary rocks and recent and sub
recent sediments forming the low-lying areas and river valleys. There are sporadic Paleozoic
granites and pegmatite and Meso-Cenozoic dykes intruding these rocks. The oldest rocks
so far dated in Kerala are the charnockites, which yielded an age of 2930 ± 50 Ma (Soman,
1997& 2002). The varied rock formations under different geological domains harbour
different mineral deposits and the transformed rock strata stockpile copious groundwater
resource. The state is gifted with ten soil types derived from the laterite base and has 12
distinct agro climatic zones. The undulating topography, vibrant climate and vivacious
hydrology in the background of ever active tectonics resulted in 44 river basins, 1750 sub
basins and 4452 mini watersheds providing multitudes of lively micro ecosystems. The
environment of these micro watersheds are conducive to varying crop types, such as,
coconut and rice in the sultry lowlands, rice, tapioca, banana, arecanut, coconut, pepper,
cashew and rubber in hot humid midlands and tea, coffee and cardamom in the cool subtropic
highlands. The micro ecosystems are such that the valleys with near waterlogged conditions
for most part of the year are seen juxtaposed with dry hilltops decked with densely canopied
trees.
1.1.1 Physiography
The altitudinal characteristics and area covered by the physiographic zones are given in
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Figure 1.1. Physiographic map of Kerala
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Table 1.1. A schematic altitudinal section across the state at the central part is depicted
in Figure 1.2, which indicates the major slope breaks characterizing different geomorphic
features.
The coastal plains and lagoons, falling in the low land is important in terms of economic
activity and demographic distribution. Beache dunes, ancient beach ridges, barrier flats,
coastal alluvial plains, flood plains, river terraces, marshes and lagoons form part of this
unit. The midland consists of dissected peneplains with numerous flood plains, terraces,
valley fills and colluviums. At places, this unit abuts the sea without intervening coastal
plains. The high ranges run parallel to the coast from the extreme north up to the south
with a break at the Palghat gap region. The southern part of the highland is characterized
by numerous peaks. A physiographic classification, identified mainly in terms of broad
geomorphic surfaces and altitudinal characteristics, is also used in the parlance of
geographers (CESS, 1984). It has five physiographic zones, namely, high ranges with elevation
above 600 m, foothill zone between 300 to 600 m, upland regions between 100 300 m,
midland between 20 100 m and coastal areas and low land below an altitude of 20 m.
Table 1.1. Physiographic units, altitudes and areas
Unit
Lowland
Midland
Highland
Altitude
Area
Area
(m)
(Km2)
(%)
0 7.5 3979.3 10.24
7.5 - 75 16231.2 41.76
> 75 m 18653.5 48.00
Figure 1.2. A profile across central part of Kerala
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!
1.1.2 Geology
Geologically, Kerala preserves the major units of the Archaean continental crust, such
as granulites, granites, gneisses and greenstones (Figure 1.3). The southern part of the
State exposes khondalite-charnockite assemblages of migmatised metasedimentary and
metaigneous rocks. The rocks in the central part are predominantly charnockites, charnockitic
gneisses and a variety of other gneisses with occasional assemblages of metasediments.
Towards the northern parts, migmatitic gneisses (hornblende-biotite gneisses) and
occasional patches of amphibolites, calc-granulites and granites are observed. There are
also crystalline limestone bands in the northern flank of Palghat Gap. Granulites, schists
and gneisses, intruded by acid and alkaline plutons, constitute the northernmost parts of
the State. The charnockites/Charnockite gneisses contain several enclaves of schistose
rocks (Soman, 1997).
The bulk of the rocks of Kerala, especially the granulites and associated gneisses belong
to Precambrian. Sporadic late Precambrian early Paleozoic granites and associated
pegmatites and Meso-Cenozoic dykes intrude these rocks. Preponderance of a variety of
gneisses, occurring within the granulite terrain, spatially associated with lineaments/faults
is a characteristic feature of the geology of Kerala. These are also associated with zones
of migmatisation and granite emplacement. Garnet-biotite gneiss, cordierite gneiss and
garnetiferous quartzo-feldspathic gneiss are seen more in association with khondalite,
while hornblende-biotite gneiss and biotite gneiss are spatially associated with charnockites.
The inland sedimentary formations, essentially of Neogene period and Quaternary period
unconformably overlie Precambrian rocks. Both marine and non-marine rocks of the Neogene
period fringe the coastal tract in two major basins of deposition between Trivandrum and
Ponnani and Cannanore and Kasargode. These include the rocks of Vaikom formation,
comprising gravel, coarse to very coarse sand with grayish clay, carbonaceous clay and
seam of lignite; Quilon formation, comprising fossiliferous limestone, sands and clays and
Warkalli Series, comprising clays with lignite bed, sand, sandy clays and sandstone.
Sediments of the Quaternary period, consisting of sands, lagoonal clays, shell deposits,
teri sands etc. unconformably overlie the Neogene sediments. The thickness of sedimentary
sequence exceeds 600 m in the Ambalapuzha-Alapuzha region.
Laterite, a weathering product of rocks, rich in secondary oxides of iron, aluminium or
both, with or without quartz and clay, is confined to elevations of 600 m and below, and
over Precambrian and Tertiary sediments. Interface of the coastal plain and lowlands is
occupied by laterite. Vast dissected laterite mesas are also widespread in the northern
parts of the State. The lateritization process began in Upper Cretaceous period and continues
till today.
The paleogeographic evolution for the formation of modern Kerala coastal zone was
reported by Suresh Babu and Thrivikramaji (1993). The important activity behind the
"
Land Environment
Figure 1.3. Geologic map of Kerala
Land Environment
#
development of present-day configuration of the the coast is the so called west-coast
faulting. This Late Cretaceous event was followed by the Western Ghat orogeny and a
number of eustatic changes and associated sea transgressions. Several events corresponding
to multiple sea level changes, fluvial disturbances in the coastal zone, formation of kayals/
lagoons and variabilities of beach sediments have left their imprint in generating an
evolutionary model. The geologically young coastal water bodies, particularly the coastparallel ones, are reportedly less than 7000 years. There are good evidences of seaward
extensions of laterite cappings and river channels from the present day shoreline, indicating
a much lower sea level positions in the past. Similarly, remnants of sea-floor fauna have
been noticed in the landward part, at elevations of more than 100m from the modern sea
level, pointing to the erstwhile transgressive phase.
1.1.3 Drainage
The State is drained by 44 rivers, of which 3 are east flowing (Figure 1.4). Rivers are
generally swift flowing having very steep gradients in their higher reaches. Absence of
delta formation is characteristic of Kerala rivers. The general drainage pattern of these
rivers is dendritic, although at places trellis, sub-parallel and radial occur. The segments of
river courses are nearly straight, indicating structural control, coinciding with the prominent
lineament directions (NW-SE and NE-SW). Many of the rivers do not have a continuous
flood plain. As per national norm (Rao, 1979), there are no major rivers in Kerala. The four
medium rivers, namely Chaliyar, Bharathapuzha, Periyar and Pamba have a total drainage
area of only 8250 km2 with length 169 km, 209 km, 244 km and 176 km respectively. The
length of rest of the rivers varies from 16 km to 130 km, with an average length of 62 km
and total drainage area of 19,485 km2. The river flow is modulated by about 30 reservoirs,
mostly located in highlands (KSLUB, 2002; CWRDM, 1995). Apart from the 44 rivers,
there are a few streams with separate watersheds draining an area of about 900 km2 with
lengths falling short of the 15 km limit set for the categorization as river (Anon, 1974)
A chain of Kayals (backwaters), lying roughly parallel to the coastline is a characteristic
feature of Kerala coast. These are mostly interconnected by natural or man-made canals.
There are 27 estuaries and 7 lagoons listed in Kerala (Anon, 1974).
1.1.4 Terrain Units
The generic process operative in Kerala is mainly marine, fluvio-marine/estuarine, fluvial,
denudational cum depositional and denudational (including structural). Due to these
processes, 22 terrain units are identified, the names and areal coverage of which are given
in Table 1.2 (Chattopadhyay & Chattopadhyay, 1995). More than 85% of the total area of
the State is subjected to denudational processes. Among this, 4% area is under scarp face
i.e. the near vertical slope of the Western ghat. Around 5% of the total area is subjected to
marine and fluvio-marine processes. The landward influence of the marine processes is
$
Land Environment
Figure 1.4. Drainage map of Kerala
Land Environment
%
Table 1.2. Terrain units and area (Chattopadhyay. S & Chattopadhyay.
M. 1995)
No
Terrain unit
Area (%) No
Terrain unit
Area (%)
1 Beach
0.5
12 Fluvio-Lacustrine Plain
0.7
2 Coastal Cliff
0.1
13 Basin/Water logged area
0.3
3 Coastal Plain
3.2
14 Low rolling Terrain
17.2
4 Coastal Plain-Laterite
0.3
15 Moderately undulating Terrain
21.7
5 Tidal/Mud flat
0.2
16 Highly undulating Terrain
15.9
6 Plain with Paleo
0.7
17 Hilly area
23.1
7 strandlines
3.2
18 Isolated residual hill
0.9
8 Flood Plain
0.2
19 Scarp Slope
4.2
9 River Terrace
0.3
20 Mesa surface
1.3
10 Alluvial Plain-I
0.7
21 Mesa side slope
0.3
11 Alluvial Plain-II
0.6
22 Hummocky terrain
1.5
Water bodies
2.9
Transitional Plain
limited to less than 4 km on an average with a maximum of 10 km in Alappuzha district.
The landscape developed by the fluvial processes accounts for 6% of the total area followed
by water bodies covering around 3% area. The area available for seasonal cultivation,
thus, is limited to less than 10% only. All the areas subjected to marine and fluvial processes,
except coastal cliff, have an average slope of less than 5%.
1.1.5 Soil
Ten broad groups of soils based on morphological features and physico-chemical properties
have been identified in Kerala (Anon, 1978). They are red soil, laterite soil, coastal alluvial
soil, riverine alluvial soil, grayish Onattukara soil, brown hydromorphic soil, hydromorphic
saline soil, acid saline soil, black soil and forest soil. Figure 1.5 depicts the latest soil map
of Kerala. It indicates 122 major soils series and 66 associations identified in the broad soil
groups (Soil Survey Organization, Kerala, 2007), most predominant being the laterite soil
(Table 1.3 a & b). Spatial distribution and physico-chemical properties of the soils are
mostly consistent with the lithological diversities of rocks as well as physiographic and
vegetational distribution pattern. Soils are well-drained over 77% of the total geographical
area of the State, moderately well drained in 6% area, imperfectly drained in 6% area and
somewhat excessively drained in about 5% area. Regarding soil depth, 2% of the total
&
Land Environment
Figure 1.5. Distribution of major soils in Kerala
Land Environment
'
Table 1.3a. Legend of Figure 1.5.
geographical area has moderately shallow soil, 2% has moderately deep, 25% has deep,
and 65% has very deep soils. With respect to soil erosion, 20% of the total area experiences
slight erosion, 70% has moderate erosion, and 4% has severe erosion ( Natarajan. et al.,
2005).
Land Environment
Table 1.3b. Legend of Figure 1.5.
Land Environment
Texturally, in the lowlands, sandy soil dominates in the beaches and dunes and clayey
soils in the runnels. Estuaries and backwaters have loamy and clayey soils with high salt
concentrations. Soils of the midland, which are lateritic in nature, are predominantly clayey
or gravelly clayey. Generally, the soils are acidic in reaction with low cation exchange
capacity and base saturation. Organic carbon content is low in the lower elevations and
high in the mid and higher elevations. Soils in the high ranges north of Palghat gap, excluding
the Nilgiris, are clayey to loamy in texture with high amount of organic matter. Soils of the
Palghat gap are neutral to alkaline. In the Nilgiris, the high hills have loamy, clayey and
gravelly clay soils, predominantly with low base saturation and fairly high Cation Exchange
Capacity (CEC). The medium hills have loamy and clayey soils. Soils of highland south of
Palghat gap have varying textures and are high in organic matter and low in CEC and base
saturation (Krishnan et al., 2005).
1.1.6 Mineral resources
The state is endowed with a number of occurrence/deposits of minerals such as heavy
mineral sands (Ilmenite, Rutile, Zircon, Monazite, Sillimanite), Gold, Iron Ore, Bauxite,
Graphite, China clay, Ball clay, Fire clay, Tile and Brick clay, Silica sand, Lignite, Limestone,
Lime shell, Dimension stone (granite), Magnesite, Quartz-Steatite etc (Nair et al., 2005;
KSLUB, 1995 and 2002). However, mining activities on large scale are confined mainly to
a few minerals. The mineral distribution map of Kerala is given as Figure 1.6. The reserves
of various minerals and mineral production in Kerala are given in Table 1.4.
1.1.7 Landuse
Kerala has a diverse land use and cropping pattern. The land reforms introduced in the
State brought in radical and comprehensive institutional changes leading to drastic
transformation in the land holding pattern. This has resulted in shift in the land use
pattern. The existing pattern of land use of the State is given in Figure 1.7. Agriculture is
the dominant land use type of the State. It accounts for over 55% of the geographical
area followed by forest land (including degraded forest) of 28% but area under non-agricultural
use is only 11% (Farm Guide, 2006).
1.1.8 Land capability
Considering the characteristics of soil, drainage/wetness, erosion, runoff etc., Kerala
has 18 land capability subclass associations of five broad land capability (LC) classes
(KSLUB, 1995 and 2002). The broad LC classes are Class II (Good cultivable land), Class
III (Moderately good cultivable land), Class IV (Fairly good cultivable lands), Class VI (Well
suited for forestry or grazing), and Class VIII (Land suited only for wildlife and recreation).
The approximate area under each class is given in Figure 1.8. The soils of Kerala has
limitations for sustained use under irrigation. Only about 37% of the area of Kerala is
suitable for irrigation with certain limitations.
Land Environment
Figure 1.6. Mineral map of Kerala (After Dept. of Mining and Geology, 2005)
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!
Table 1.4. Mineral reserves (2000-01)
No Name of
Minerals
1
2
3
4
5
6
7
8
9
10
Ilmenite
Rutile
Sillimanite
Zircon
Monazite
Bauxite
Graphite
Silica sand
Quartz
Limestone
Reserve Production No Name of
(x
(tons)
Minerals
106tons)
78
6
20
14
1.5
12.5
2.046
28.4
-24
147548
8649
8645
19291
452
14281
50
122931
1775
468401
11
12
13
14
15
16
17
18
19
20
21
Lime shell
China clay
Granite
stone
Iron ore
Gold
Ball clay
Fire clay
Scheelite
Magnesite
Gemstones
Lignite
Reserve
(x
106tons)
Production
(tons)
1.26
120
--32.8
--1.67
9.65
--0.033
---8.95
38600
449506
3808
-----------------
Values in percentage
Fo res t la nd
27 .83
No n a rab le la nd
B a rre n /U nc u ltiva te d
P a st u res / Gra zin g
M isc . tre e c rop s
5 5 .46
1 1.0 6
A rab le w a st e
Fa llo w
0 .74
1 .7 7
0 .01
1.0 5 1 .8 0 .26
Cu rre n t fa llo w
Ne t a rea so w n
Figure 7. Landuse pattern, Kerala
"
Land Environment
8.6%
0 .7 4 %
6 .5 7%
7.07 %
1 .7 9%
3.2 5%
3 6.1 5%
1 6.4 9%
9 .34 %
C la s s II
C la s s III
C las s III-IV
C la s s IV
C la s s IV-VI
C las s VI
C la s s IV-VIII
C la s s VI-VIII
O the rs
Figure 1.8. Area under different Land
1.2. Environmental Issues
The increased pressure on land due to demand for more resources to satisfy the need
and greed of mankind caused the upward spread of cultivation into steeper areas better
left under forest. This unscientific change in land use has taken its toll on the fertile top-soil
layer. The problem is severe in Kerala, a narrow strip of land closer to the sea, with all the
ingredients like high rainfall and increased human activities that can accelerate the rate of
soil erosion. There are human interventions in the form of mining, quarrying, filling of water
bodies, etc leading to significant land modification. This would influence the biophysical
system and adversely affect the ecological security and environmental stability.
There are also issues of seismicity, landslides, floods etc which has a bearing on the
environmental quality. Continued industrialization and urbanization exert further pressure
on the land increasing the level of degradation and pollution and decreasing the ecological
diversity of land environment. Therefore, it is necessary to evolve a framework for
sustainable development, the preliminary step of which is to understand the status of land
environment and evolve appropriate management action plans.
Land Environment
#
The major environmental issues confronting land environment are the following.
1.
Landuse change
2.
Mining
3.
Soil erosion
4.
Soil quality deterioration
These issues are analyzed in terms of their driving force, pressure, present status, and
impact and actions taken to mitigate/manage these issues.
1.2.1 Landuse change
There has been significant change in landuse over the years. The State conceived and
implemented a progressive Land Reforms Act with an objective of sustainable use of all
productive land through the involvement of the entire population by distributing land to the
landless. Over the years, there was a sharp decline on the size of land holdings and
accelerated effort for increasing production and income. Over the last two decades, there
is a decline in agricultural landuse. Landuse changes are manifested, generally, as change
in cropping pattern, quarrying, slope modification, soil excavation, conversion of paddy
lands and swampy areas and filling of wetlands etc. Such changes affect the environment
adversely by way of intense soil erosion, water logging, water scarcity, mono cropping and
loss of biodiversity. The terrain modifications, generally effected as a prelude to land use
changes, at times, lead to catastrophic incidences of landslides and increased recurrence
of earth tremors, land subsidence etc.
1.2.1.1 Driving force
Population growth, migration, urbanization, industrialization and globalization had led to
significant landuse change in the State. With increase in population, the need for housing
and urban infrastructure increased considerably. The migration to highlands, in search of
virgin land for cultivation, led to reduction in natural vegetation. The growth of both small
scale and large scale industries requiring new infrastructure necessitated conversion of
agricultural lands. There was need for increased production and income from each parcel
of land to sustain agricultural practices. The requirement of subsistence necessitated shifting
to agricultural produces that can compete in the market, but compromising, often, on biophysical suitability of the land and desirable landuse.
Increase in population reduced the per capita land availability in Kerala. Increasing
population density, decreasing per capita land availability, improved education level, rising
unemployment led to migration to regions both inside and outside the country. The migration
of farmers to eastern highlands, in search of more fertile land for cultivation started in the
last century, resulted in significant deforestation in the high ranges and loss of natural
$
Land Environment
vegetation in the foothill regions or eastern midlands. In the high ranges, plantations replaced
the natural forests and in foothills, seasonal cultivation took away the natural vegetation.
Since the land used by the migrants was originally encroachments, agriculture sustainability
was not a serious concern for them. The migration of educated unemployed to regions
outside the State or Country led to enhanced income to the family and reduced the necessity
of subsistence on agricultural income. Investments of the increased income have mostly
been on land acquisitions, construction of residential villas etc., invariably changing the
thrust on traditional landuse practices. The State was characterized by a net influx of
immigrants until 1941, but later the situation was reversed, with more people emigrating
out of Kerala.
Change in life style and aspirations of the people also has a bearing on landuse change.
Change in the social system from traditional joint family set up to nuclear families divided
the larger land holdings of joint families to small parcels, which led to fragmentation and
intensive use of land but its poor upkeep as an integral part of local ecosystem. The
preference to homestead settlements necessitated more land for housing. The state is
dominated by small and medium well-distributed urban centers rather than large megacities, displaying a unique rural-urban continuum. This necessitated more land for urban
infrastructure, local enterprises and housing. Land for such development is generated through
filling of wet lands, modification of slopes and leveling of hills (see Photographs). Shift in
government policies and social engineering by market forces also has influenced the landuse
Paddy field under reclamation
Road being laid across a paddy field
Buildings constructed by modifying slope
Wetland being reclaimed
Land Environment
%
changes. The incentive to cash crops and marginalization of support and incentives to food
crops, over the years, changed the cropping pattern without any consideration of biophysical
production potential of land parcels. Industrialization of the state is also not fully attuned to
the agricultural potential, though there is recent and marginal policy shifts.
1.2.1.2. Pressure
Over the last one century, rural and urban population of Kerala increased by 4 and 18
times respectively, registering a five fold increase on the whole. In 1901, the population of
the State was only 6.4 million which almost doubled in 40 years. The next doubling took
only 30 years, but further, the decadal growth rate in the state is declining. Population and
its decadal growth rate are given in Figure 1.9. The population density, a mere 165 persons/
km2 in 1901, increased to 819 in 2001, exerting significant pressure on land as the per
capita land availability dropped from 0.61 ha to 0.12 ha. Demand on land for housing and
urbanization also rose many times, resulting in the decline of availability of agricultural
land. During 1901 to 2001, the urban population registered a phenomenal growth, from 7%
to 26%. The cropping intensity was 140% during 2006.
P O P U L ATION G R OW T H - K E R AL A
30
P O P U L AT IO N - D E C AD AL G R OW T H R A T E
300
25
R ural
250
Gr o w th rate (% )
P o p u la ti o n i n l akh s
350
U rban
200
Tot al
150
100
20
15
10
50
5
0
0
1 981 19 91 20 01
01
91
1951 1 961 1 971
20
19
71
61
51
81
19
19
19
19
31
21
11
41
19
19
19
19
19
01
19 01 191 1 192 1 193 1 1941
Figure 1.9. Characteristics of population growth in Kerala
Kerala suffers from very high unemployment. The rise in job expectations resulting
from increased education levels has not corresponded to an increase in employment
opportunities within the state. Indeed, approximately 10 percent of the Indias total
unemployed population lives in Kerala. Unemployment, then, fuelled large-scale migration
both within and outside the country. Over half of the migration from Kerala is to foreign
countries. The emigration rate was 0.22 percent between 1971 and 1981, when
approximately 250,000 persons left Kerala for employment in the Middle East. This trend
continued during the 1980s, with a net migration rate of 0.31 percent. It is estimated, in
1992-93, that there are almost 1.2 million migrants from Kerala, of which 56 percent
migrated to the Middle East and other foreign countries and 44 percent to other parts of
India (Dept. of Economics and Statistics, 1997).
&
Land Environment
The migration to highlands in search of more agricultural land led to considerable
encroachment on forest land. However, the official estimates continue to indicate no change
in forest area. The forest cover assessment made by Forest Survey of India during 2001
using satellite data recorded an area of 15560 km2 of which dense forest was 11772 km2
and open forest was 3788 km2. As per the provisional figures as on March 2005, the area
of forest is 11244.691 km2 (SPB, 2005). This includes 9277.765 km2 of reserve forest,
126.008 km2 of proposed reserves and 1840.919 km2 of vested forests.
It is widely known that in certain regions large-scale deforestation and conversion of
forest area occurred. The topographical maps available since 1900 and LANDSAT images
(1973 and 1983) indicate a substantial decline in forest vegetation cover over the years
(Chattopadhyay, 1985). In 1905, the forest vegetation was 44.4% of the total area which
declined to 27.7% by 1965, to 17.1% by 1973, and to 14.7% by 1983. However, the
actual forest area that sustains forest biodiversity and functions of forest ecosystem is
only less than 8% of the total area (Satishchandran, 2002). Varma and Abin (2005) recorded
1.7 times increase in settlement area and 3.2 times increase in area under plantations by
converting forest land within a micro watershed of 26 km2 at Mankulam, Munnar during
the period from 1976 to 2003 (Figure 1.10).
The most significant changes in the landuse pattern are the shrinking of area under food
crops and increase in the rate of deforestation. When the State was formed in 1956, total
cropped area was over 2 million hectares. Rice was the dominant crop, accounting for
about 35 percent of the cropped area, followed by coconut, accounting for 21 percent.
Land area under rice cultivation declined from 7,53,009 ha in 1961-62 to 2,75,742 ha in
2005-06 (Dept. of Economics and Statistics, 2006). During the same period, rice production
10° 07' 46"
7
5
3
Watershed
Watershed terminal
terminal
Mankulam
Mankulam
0
0.75
10° 07' 46"
10° 07' 46"
°
'
"
1.5
0
Mankulam
Kilometers
Thalumkandam
Thalumkandam
76°
58'
30"
Watershed terminal
0.75
1.5
Kilometers
Thalumkandam
Me
lac
Munipara
Munipara
er
Parvati Mala
Viripara
Pazham Mala
Drainage
Drainage
Kampani
Kampani Kudi
Kudi
Weir
Weir
River
Dense forest
Kampani Kudi
Weir
Dense forest
Cardamom Plantation
Cadamom plantations
Open forest
Settlement
Tea plantations
Open forest
Settlement
Eucaliptus plntation
°
'
"
Rocky area
10° 03' 31"
Riv
Viripara
Pazham
Pazham Mala
Mala
River
Munipara
ry
Aranasari
Mudi
Parvati
Parvati Mala
Mala
her
er
Riv
ry
her
lac
Me
Aranasari
Aranasari
Mudi
Mudi
Rocky area
76°
58'
30"
10° 03' 31"
Figure 1.10. Landuse/cover change in a high range micro watershed (Mankulam) from
1976 to 2003 (Yellow portion indicates increase in settlement area)
Land Environment
'
declined from 9,88,150 tons to 6,29987 tons. This downward trend was quite steady over
the years (Figure 1.11). The increase in yield during this period was inversely proportional
to decrease in cultivated area. As a result, the local rice production barely meets one-sixth
of the total consumption requirements of the state. Similarly, there was an up trend or
down trend for area and production during the period with respect to other crops as well.
The changes in agricultural landuse and the crop production are given in Table 1.5.
During the past 44 years, the area under rice and its production decreased by 63% and
13
12 .7
14
4
1 0. 9
1 98 0- 81
1 99 0- 91
1 99 5- 96
6 .6 7
6 .3
1 99 6- 97
5 .7
6
1 97 0- 71
5. 6
4.7 1
4.3 1
3 .8 7
3 .5 2
3 .5
3 .4 7
3 .22
3 .11
2 .87
2.9
2.7 6
8
8
8 .7
10
1 96 0- 61
9 .5 3
8 .7 1
7. 65
7. 27
7. 7
7. 51
7.0 4
6 .8 9
9.8 8
12
7 .53
A re a ( La kh H a) & P ro du c tio n (L ak h ton es )
A re a a n d P ro du c tio n o f R ic e , K e ra la
1 99 7- 98
1 99 8- 99
1 99 9- 00
2 00 0- 01
2 00 1- 02
2 00 2- 03
2
2 00 3- 04
2 00 4- 05
0
2 00 5- 06
A rea
P rod u cti on
Figure 1.11. Details of rice cultivation in Kerala
36% respectively. During the same period, area under coconut and its production increased
by 78% and 95% respectively. Increase was substantial in the case of rubber (area =
271%; yield = 2906%). In 1996, when the total cropped area was just over 3 million
hectares, coconut was the primary crop, followed by rubber and then rice.
A case study by Kerala State Land Use Board (KSLUB, 2006) with respect to long-term
decline of paddy-land area in Wayanad District revealed that nearly 50% of the paddy
fields have been already reclaimed and the remaining fields are under serious threat of
conversion (Table 1.6). The conversion at Pozhuthana, Muppainadu and Vythiri grama
panchayaths are of the order of 97%, 93% and 87% respectively during the last 35 years.
The paddy lands of Kalpatta Municipality are also subjected to high level of conversion to
the tune of 93%.
Land Environment
Table 1.5. Changes in crop area and production, Kerala, 1961-62 & 2005-06
Sl
No
Crop
Area (ha)
Production (Tonnes)
1961- 2005%
1961-62 2005-06
%
62
06 variation
variation
1 Rice
753009 275742 -63
988150
629987
-36
2 Tapioca
236776 90539
-62
1618713 2568284
59
3 Coconut 505035 897833
78
3247mn 6326mn
95
4 Pepper
99887 237998 138
26550
87605
230
5 Cashew
55051 78285
42
84449
68262
-19
6 Rubber
133133 494400 271
24589
739225 2906
7 Groundnut 15993 3299
-79
13533
2441
-82
8 Seasamum 11953 600
-95
2539
210
-92
9 Cotton
9587 2655
-72 23751bales 3452bales -85
10 Pulses
43546 10562
-76
16889
7940
-53
11 Ginger
12050 12226
1
11185
56288
403
12 Turmeric
4847 3384
-30
4267
8237
93
13 Banana
42693 61400
44
55443
491823
787
14 Tobacco
704
43
-94
915
69
-92
15 Total
766381 278617 -64
999566
631591
-37
cereals
16 Arecanut 56764 108590
91
8091mn 24478mn 203
17 Coffee
18807 84644
350
8145
60175
639
18 Tea
37426 35043
-6
37428
56384
51
(Source : Dept. of Economics and Statistics, 2007)
Table 1.6. Level of conversion of paddy land in Wynad
Block
Total paddy area (Ha)
Conversion
1970
2005
(%)
6255.48
2463.17
60.62
Sulthan Batheri
10005.97
6108.86
38.95
Manathavady
10017.25
5369.74
46.40
479.16
35.26
92.64
26757.06
13977.03
47.46
Kalpetta
Kalpetta
Municipality
Total
Land Environment
The year 1975 is considered a major turning point in cropping patterns; the area used
for rice cultivation reached its peak that year. After 1975 there was a clear shift away
from food crops, mainly rice and tapioca, in favor of tree crops such as rubber and coconut
and some export-oriented crops such as pepper, ginger, and coffee. As a result, area under
coconut, pepper, coffee, rubber, cashew, and fruits increased, while cereals, sugarcane,
and tea declined in area. These shifts have significant implications for the food security of
the state, which already depends on outside supplies to meet more than half its food
requirements. Out of a gross cropped area of 29.42 lakh ha during 2004-05, food crops
comprising rice, pulses, minor millets and tapioca occupy only 13.6 percent. Kerala State
which had a low base in food production is facing serious challenges in retaining even the
meager area. Keralas agricultural economy is undergoing structural transformation from
the mid seventies by switching over a large proportion of its traditional crop area which
was devoted to subsistence crops like rice and tapioca to more remunerative crops like
rubber and coconut.
1.2.1.3 State
The state level aggregate data do not capture the dynamic processes involved in the
states land use transformation. This is due to the wide variation in physical settings and
development patterns in Kerala. The changes in landuse pattern over the recent years are
given in Table 1.7. It does not reflect any perceptible improvement in the extent of landuse
for agriculture.
Table 1.7. Change in landuse pattern
(% of total geographical area).
Ty p e o f la n d u se
Fo rest land
Non ar able land
Bar ren/uncultivated
P astur es/Gr azing
M is c. tree c rops
Arable w aste
Fallow
Cur rent fallo w
Net ar ea sow n
To tal
2002-03
27. 83
10. 12
0. 76
0. 01
0. 26
1. 8
1. 05
1. 77
56. 4
100
2003-04
27.83
10
0.76
0.01
0.31
1.82
1.01
1.8
56.46
100
2 0 0 4 -2 0 0 52 0 0 5 -0 6
27.83
10.52
0.74
0.01
0.28
1.66
0.92
2.09
55.95
100
27.83
11.06
0.74
0.01
0.26
1.8
1.05
1.79
55.46
100
Land Environment
Kerala forests fall in two bio-geographic provinces of Western ghat and West coast,
and are rich in bio-diversity. This is vital for environmental protection and is considered to
be a repository of rare and endangered flora and fauna. The forest type shows wide variation
ranging from tropical wet evergreen to tropical dry deciduous. Out of the total area, 1.88
lakh hectares is degraded forest with crown density less than 40%. The area under
tropical wet evergreen, semi-evergreen and tropical moist deciduous together constitute
79% area, tropical dry deciduous 1.06% and forest plantation 10%. The mangrove habitat
is also a seriously endangered eco-system in the State. Their area has been reduced
considerably from about 100 km2 in the beginning of the last century to about 50 km2 at
present. The eco-system remains as fragmented and is distributed in different locations of
the State.
The area under varous important crops in the state is given in Figure 1.12 (Dept. of
Economics and Statistics, 2006). Present trend reveals that Kerala is being converted to
non-food crop area, and the ratio of food crop to non-food crop area is 13:87. Conversion of
land used for rice cultivation to seasonal and perennial crops reflects a shift in cropping
pattern. When rice land was put to nonagricultural uses, 44 percent went for buildings.
Starting with tea plantations in Peermedu in the 1870s, the area under plantations
registered a phenomenal increase over the years. Area under major plantation crops in
8
5
41
2 79
89
2 90
29
55
481
9
8 99
11 3
85
231
35
82
5
1 08
P addy
C ereal s/ M illet s
P uls es
Tapioc a
Tubers
V eget ables
P lant ains
O t her fruit s
C oconut
O ther oil s eeds
A recanut
C ashew
Tea
C offee
C ocoa
Rubber
C ardam om
O t her S pic es
Figure 1.12. Crop distribution, Kerala
Land Environment
!
Kerala is given in Figure 1.13 (Nair et al., 1999; Dept. of Economics and Statistics, 2006).
Kerala contributes a substantial share to the national economy with respect to four plantation
crops viz rubber, tea, coffee and cardamom. These collectively account for 29 per cent of
the net cropped area. Rubber plantations in Kerala account for 83 percent of the total
rubber area in the country. Area under coffee registered sustained increase during the last
two decades. As against the total area of 5.11 lakh hectares under tea in the country,
Kerala accounts for only 0.37 lakh hectares, showing a marginal decline, so is the area
under cardamom during the last five years.
Area in Hectares
35 0 00 5 0 0 00
75 0 00
3 5 04 0
Coc onut
Rubber
1 07 5 7 2
Cas hew
8 4 64 4
Coffee
8 1 5 47
8 99 2 6 7
Arec anut
Tea
4 8 06 6 1
Teak
Euc alypt us
Ot her tree s pec ies
Figure 1.13. Distribution of plantation crops
Area under urban administration in 1991 accounted for 8.65 percent of the geographic
area, compared with 2.66 percent in 1961. District-wise, with the exception of Ernakulam
and Kannur districts, the spatial expansion of urbanization is either stagnant or slow. In
1961 Alappuzha district ranked first among all the districts in urbanization as 7.79 percent
of its total area was classified as urban. The situation remained unchanged up to 1981,
and an additional 12.54 percent of the total area came under urban administration in 2001.
The impacts of urbanization on landuse are felt widely. An analysis of the landuse dynamics
of the city of Thiruvananthapuram illustrates these changes (Chattopadhyay, 1991). The
city had an area of 32.6 km2 and population of 57,882 by the turn of the nineteenth century,
which had grown to 74.93 km2 and 524,006 in 1991. By 2001, the City Corporation of
Thiruvananthapuram occupied an area of 141.74 km2 and a population of 744,983. The
"
Land Environment
early settlements were in low-lying sandy areas. The landuse changes over the years were
instrumental in changing the landscape ecology, which had far-reaching consequences for
the environment. Major land use changes were in residential areas. This was due to the
preference of the local populace to live in single-family housing, and hence more land was
required to house the population than in other parts of the country. A comparison of the
land use data for Thiruvananthapuram for 1961 and 1976 revealed that the areas classified
as wetland, rice fields, and parks and open spaces declined cumulatively from 36.5 % to
17.45%. The survey revealed that wetland made up only 5 percent of the region. This
decline continues despite restrictions imposed by the government against conversion of
wetland, earmarked as Green Belt. In urban areas, generally, the urban influence is
spreading to surrounding rural areas, and the ruralurban distinction is fast diminishing. In
the Thiruvananthapuram City Region, for example, rice fields accounted for 11 percent of
the total area in 1966, but only 6 percent in 1991 according to satellite data.
1.2.1.4. Impact
The downward trend in rice production has impact on food security and rural employment
opportunities, and raises serious concerns on ecology. Landuse has important implications
on sustenance of life systems. Agriculture and forest take the major share of landuse.
Population pressure and rising demand for food, clothing and shelter and other life systems
besides economic motivation of human beings have resulted in over exploitation of land in
the previous and present century. This resulted in many natural disasters and even threat
to the sustenance of life system.
Unscientific agriculture aimed at short term benefits to man kind, resulted in land
degradation and natural disasters such as flood, drought, land slides, soil erosion, stream
bank erosion, sea erosion, salinity etc. This also reduced the productive capacity of land
to a large extent. In order to compensate for this, enhanced use of chemical fertilizers was
resorted to in the State as given in Table 1.8, which led to dangerous quantities of their
Table 1.8 Consumption of Fertilizer nutrients (tons) in Kerala
Year
Nitrogen (N)
Phosphorus (P2 O5)
Potash (K2O)
Total
2000-01
73756
37600
61849
173205
2001-02
76417
37237
63471
177125
2002-03
86659
40212
77786
204657
2003-04
85433
38955
67738
192126
(Source: Dept. of Economics & Statistics, 2006)
Land Environment
#
residues in soil and the water. In Kuttanad alone, about 8400 tonnes of nitrogen, 5000
tonnes of phosphorous and 6800 tonnes of potash are applied annually for various crops.
The phosphate and sulphur content in the Vembanad lake water indicates higher values of
the order of 7 mg/l and 200 mg/l consequent to fertilization application. The level of ammonia,
(2 mg/l), is also high due to the enrichment of nitrogen in the lake waters from the application
of fertilizers and biodegradation of organic wastes (Nair and Unni, 1993).
The conversion of area, once under paddy, is mostly for non-agricultural purposes or for
plantations, by filling, partially or fully. The filling of such low lands increases surface
runoff resulting in floods and reduced water conservation. The latter leads to lowering of
water table and derangement of natural drainages and consequent drought
The hillocks in the rolling to undulating topography, host a cafeteria of plant species and
numerous macro/micro drainage channels, enabling biodiversity preservation and conservation
and recharge of water. Destruction of such settings is rampant in Kerala, mainly for
reclamation of wetlands including paddy fields, endangering both the ecosystems and
seriously affecting the food security and ecological stability of the State. The ultimate
effect of quarrying, whether it is soil or rock, is the disappearance of hillocks. It may have
a bearing on the climatic pattern of Kerala as 13% of the annual rainfall, received during
the summer is mostly due to thunderstorm activity, which is a local phenomenon (Kutty,
1996). Probably, such local phenomena are influenced by topographical undulations, air
turbulence, localized cloud accumulation etc.
Quarrying also leads to disfigurement of landscape by which the stream network and
properties may change and scars across the slopes may develop. Unscientific openings or
layout of quarry plan might trigger a land slide or land slip. The activities such as clearance
of vegetation for cultivation, settlement, quarrying and filling of low lying areas and the
rainfall pattern affect the hydraulic characteristics and accentuate hydro seismic activities
(Kusala Rajendran and Rajendran, 1996).
Substantial area of the State is under mono cropping with rubber, tea, coffee, cashew
etc. Cultivation of plantation crops reduces the opportunity for intercropping with banana,
pepper, ginger, turmeric etc. The raising of plantations in place of natural forests will
affect the interception and storage of water facilitated by the forest cover, which in turn
have an impact on the water balance. Compared to natural forests, the humus cover of
plantations is very shallow. The largest influence of a plantation on hydrology occurs during
the establishment phase of a plantation, i.e. during the first 1-3 years of planting, when
most of the soil surface is exposed (Nair et al., 1999). The loss of top soil in teak and
eucalyptus plantations is estimated to be 4 to 15 t/ha/annum (Thomas et al., 1997). A
generalized rate of soil loss under different landuses published by the Ministry of Rural
Development, Government of India is given in Table 1.9.
$
Land Environment
Table 1.9. Generalized rate of soil loss according to landuse
Landuse
Bare soil
Annual crops poor management on infertile soil
Annual cropping standard management
Annual cropping good management
Perennial crops little disturbance
Natural forest
Soil Loss Rate (tonnes/ha/yr)
125.0
50.0
10.0
5.0
2.0
0.5
1.2.1.5 Response
The conservation, development and management of land resources based on agroecological and social parameters are vital and it requires resource based landuse planning
for agricultural and non-agricultural uses with special consideration for fragile ecosystems
such as paddy fields, high lands etc. In order to achieve this, the State launched a programme
in 1989 for mapping the land and water resources, landuse and infrastructure facilities of
Grama Panchayaths with the participation of local people. The project named Panchayat
Level Resource Mapping programme was launched through the Centre for Earth Science
Studies (CESS) and Kerala State Land Use Board (KSLUB) with the support of Integrated
Rural Technology Centre (IRTC), Mundur, Palakkad. It envisaged preparation of micro level
thematic maps on landform, relief, surface material and water availability in 1:12500 scale
by the scientists and landuse and asset in 1:4000 scale by the local volunteers. Based on
these thematic maps, an environmental appraisal of each panchayat was carried out to
identify the issues and management suggestions for each terrain units. The project was
implemented in 64 panchayats in this mode. Subsequently, the programme was extended
to all the panchayats to prepare landuse and asset maps using cadastral scale base maps.
The programme enabled scientific evaluation of land and water resources by the scientists,
on the one hand, and mapping of existing landuse and assets by local volunteers, on the
other. Such data were used together to carry out an environmental evaluation of the area
to evolve an eco-conformable development strategy through participatory perspective
planning and location specific development action plans. This aided the decentralized planning
and development process being implemented in the State.
Subsequently, the State also launched a major campaign for preparing development
master plan on the basis of micro watersheds. The programme enabled preparation of
watershed appraisal report in 152 Blocks of the State which is of assistance in taking up
watershed development programmes sponsored by different agencies. Watershed based
conservation and development programmes are of paramount importance to the State for
mitigating the problem of land degradation, enhancing the quality and quantity of land,
Land Environment
%
water and biological resources, curtailing drought incidences and minimizing floods. It also
enabled waste land development and dry land agriculture.
The Government brought out the Kerala Land Utilization Order of 1967 with provisions
to ensure desirable landuse in each parcel of land. However, the limitations of institutional
mechanisms and supportive technical contents do not permit its effective implementation
in the State.
The State initiated the System of Rice Intensification (SRI) in various districts through
the Department of Agriculture for increasing the productivity of rice. However, the
requirement of increased labour use as well as facilities for water management needs
adversely affected its popularity. The State Poverty Eradication Mission, Kerala promoted
lease land farming in Kerala namely Harithashree through various Kudumbasree units for
enabling women farmers to stay on in agriculture. As a result, the initiative would uphold
desirable landuse. The area coverage and the involvement of Neighbourhood Groups
registered 23% growth in one year after its introduction in 2003-04.
1.2.2 Mining
Mining of natural resources is a process involving intervention in the land environment,
the magnitude and intensity of which vary based on the type of mining and environmental
fragility of location. It also involves extreme disturbance to biological life systems, in general,
and violation of the rights of local communities in particular. India produces 89 minerals,
out of which 4 are fuel minerals, 11 metallic, 52 non-metallic and 22 minor minerals. In
2000-2001, the total value of mineral production, other than petroleum and natural gas,
was Rs. 306,751 million. Kerala also has its due share, particularly in the field of minor
minerals. The mineral wealth of Kerala and distribution of mineral resources in the state
are given in Table 1.4 and Figure 1.6. The major mining activity in the State is confined to
the beach placers and china clay deposits. The unorganized mining, especially with respect
to tile and brick clay, alluvial sands, crystalline rocks, soils etc, is posing serious threats on
natural resource system and societal well being. The poor planning and implementation of
environmental management systems, lack of periodic environmental monitoring and corrective
measures etc aggravated the issues due to mining.
There is indiscriminate mining activity in the state without considering the environmental
repercussions. The systematic mining, based on mine plan and post mining rehabilitation, is
taking place only in the case of placer minerals by the government owned companies. The
rehabilitation measures are often not commensurable with the environmental stress due to
mining as the activity is confined to a very fragile ecosystem area. The arbitrary clay
mining from various paddy fields and sand mining from various rivers have degraded the
wet land ecosystem in general. The adverse impact due to rock and soil quarries is on the
&
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increase. Unorganized mining is reported even in placer mineral mining sector. Among the
natural minerals, mica had completely been mined in the past and no activity is reported
today. Certain of gem minerals from alluvial gravels as well as from pegmatite veins and
placer gold from upstream beds of rivers are not being extracted by the organized sector in
the State. Many of the mineral occurrences are in very fragile physical, biological and
social environments, increasing the necessity of post mining interventions.
The mining activities in the state are spread out in various districts and the State
Government has issued 103 mining leases, 372 quarrying leases 4000 quarrying permits
and 94 dealer licenses (Source: http://dgfasli.nic.in/publication/reports/kerala/chapter2.htm).
The total area covered by mining leases in Kerala is given in Table 1.10 (http://
www.prd.kerala.gov.in/ power main. htm).
Table 1.10. Total area covered by mining lease
Minerals
Clay
Silica Sand
Bauxite
Graphite
Limeshell
Limestone
Mineral sand
Quartz
Total
Area (in Ha)
96.4168
44.6522
1.3739
0.5909
1786.3855
247.5
286.842
6.0098
2469.7711
In the beach placer mining sector, approximately 5000 people are employed by the
Indian Rare Earths Limited (IREL) for gathering and separation of mineral sand. Besides,
indirect employment is provided to about 1500 people for transporting, shipping etc. The
Kerala Minerals and Metals Limited (KMML) have 2000 employees. The river sand mining
is mainly in unorganized sector and it is estimated that more than 60,000 persons earn
their livelihood through the extraction of river sand. Similarly, large sections of people are
working in clay mining and rock quarrying activities. The interests of employees are
protected, largely through legislation and the Kerala Minimum Wages Rules 1958.
The mineral resources play a significant role in the economy. Especially, the beach
placer (black sand) deposits of the State are known to be the largest in the world. The
share of black sand mineral resources in the economy of the state is given in Table 1.11.
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'
Table 1.11. Production and sale of mineral sand in Kerala during 1999-2000
Production
(Tonnes)
136908.74
Sales Value
(Rs.in lakh)
3786.42
Rutile
9201.00
2941.50
Zircon
14037.00
---
Sillimanite
9595.00
244.79
Leucoxene
745.00
---
Zirflor
4920.00
942.09
106.00
1.74
175512.74
9828.85
Name of Mineral
IImenite
Microzir 1&10
Total
The statistics of other resources are not available. The IREL meets the domestic requirement
of mineral sands, particularly ilmenite, of the Travancore Titanium Products (TTP),
Thiruvananthapuram, Cochin Mineral Rutile Limited (CMRL), Kochi and zircon to a large
number of entrepreneurs in the private sector. It also exports ilmenite sand to USA,
Canada, UK, France, Germany and Japan. IREs Thorium plant at Aluva is one of the largest
in the world and supplies the entire requirements of the vast gas mantle industry in India.
Exports are also made to Bangladesh, Turkey, Austria, Germany, Netherlands and Japan.
Further, the thorium oxide manufactured by this unit is an input for the Fast Breeder Test
Reactors. The KMML exports the finished product, Titanium dioxide, in different grades to
many countries.
There is increasing demand for refined Kaolin (China Clay - both Spray Dried and Rotary
Dried), Metakaolin and Calcined Kaolin (clays) to cater the paper, paint, rubber, plastic,
fiberglass, cement and ultramarine industries, in India and markets in Africa, South East
Asia, Far East and Middle-East. This necessitates increased mining of the china clay resources
to meet the industrial demand. Pottery from ball clay deposits also bears good market
demand. Crystalline rocks are mined extensively for making polished slabs and for
manufacture of artificial sand and metals, in addition to the production of rubble. They are
mainly meant for domestic market requirements.
Silica sand is targeted for various applications like glass bottles, sand lime bricks, sodium
silicate and silica gel. They are used within the state and elsewhere in the country. The
present users include the Excel and Ogale glass manufacturing units at Alappuzha and
Aluva respectively as well as lime sand brick making unit at Pallippuram near Cherthala.
Compared to the reserves of the deposit, their use is meager at present, though its
!
Land Environment
applications extend to high-end-fields like optical glasses, silicon metal etc. Due to the
shortage of construction quality alluvial sand, beach sands are being heavily exploited for
land-filling as well as in construction sector. Such uses of silica sand in construction industry
or for filling low land is actually an under utilization of this valuable material.
The demand for river sand is very high and all the rivers and its tributaries are subjected
to indiscriminate removal of sand. The decline of aggregate grade sand in the rivers shifted
the focus of mining to paleo channels. There is also increasing import from other states
and also popularization of manufactured sand- a crushed rock material. However, the export
of river sand from Kerala seems to be more than the imports.
Though no mine development took place so far, the potential for gold extraction is
expected to be good in Kerala. The reserve estimation talks that grade of gold varies from
0.08 to 0.53 g/t at different segments of Nilambur area and from 0.22 to 14.99 g/t at
Attappady area. In the case of lateritic gold in Wayanad, the gold grade ranges from 0.03
to 0.1g/t. River gravels of Chaliyar and Punnapuzha are repositories of placer gold. Geological
Survey of India estimated 69.590 ounces of gold in a total volume of 8.5 Million m3 of
gravel in the Nilambur valley.
Currently, the users of lime shell in the State include the Travancore Cements Ltd.,
Nattakom for white cement manufacture, the Travancore Electrochemical Industries,
Chingavanam and the Pallathra Bricks and Tiles Ltd., Cherthala. These companies use lime
shells from the Vembanad lake. Earlier, the Gwalior Rayons Ltd., Mavur used to buy extracted
lime shell deposits in Kozhikkode and Kannur districts
1.2.2.2 Pressure
The multi mineral assemblage in the beach placer sands open up a wide spectrum of
industrial applications in many fields ranging from the aerospace industry to ceramic and
paint industries. Kerala has the richest beach placer deposits in the world with an average
content of about 45% heavy minerals in the beach sands and about 5 to 7 % in the inland.
Many of the deposits in other parts of the world which are now being mined contain only 1
to 3% heavy minerals. The quantity of minerals present in this deposit are of superior
nature with TiO2 content of 60% in ilmenite and 95% in rutile, 67% ZrO2 in Zircon and
64% Al2O3 in sillimanite. Therefore, mining of beach placers from Kerala is very profitable.
However, the occurrence of the reserve in areas of high population density and fragile
environment exert considerable pressure on expanding the mining activity.
The Indian Rare Earths Limited (IREL), a Government of India Undertaking (Department
of Atomic Energy) and Kerala Minerals & Metals Ltd. (KMML), a Government of Kerala
Undertaking are engaged in mining, production and processing of heavy minerals from the
beach sand deposits at a few locations in the state. The IREL is mining from Chavara
beaches since 1965 and the KMML since 1972. The important minerals being mined from
Land Environment
!
beach placers are ilmenite, rutile, leucoxene, zircon, sillimanite and monazite. While KMML
produces around 30,000 tons of ilmenite per year, which is basically for the manufacture
of titanium dioxide pigment, the IRELs share is of the order of 1.5 lakh tons of ilmenite,
10,000 tons of rutile, 12,000 tons of zircon, 7000 tons of zircon and 1200 tons of monazite,
basically for exports. The current sales turn over of IREL is around Rs.700 million and that
of KMML is reported as around Rs.300 million.
China clay is used in paper, ceramics, refractories, rubber, insecticides, cement, paint,
textiles and fertilizer industries widely. It is also used in the manufacture of abrasives,
asbestos products, fiberglass, chemicals, cosmetics, pharmaceuticals, electrical wares,
glass etc. The widespread use of the material demand high magnitude mining. The reserve
is concentrated only at selected locations of Thiruvananthapuram, Kollam and Kannur
Districts. The high grade clay that is used for paper coating and pharmaceuticals are
concentrated only in the deposits at Thiruvananthapuram and Kollam. The tile clays are
used for the manufacture of tiles and bricks, the availability of which is diminishing. The
excessive removal of tile clays from paddy fields has converted the areas as fallow lands.
It is estimated that the total quantity of river sand used in Kerala is about 32 million
tons. In addition, a substantial quantity of sand is being transported to neighbouring states.
It is estimated that 41 truck loads of sand is being taken to outside states from Bharathapuzha
and Periyar River basin alone. The demand for river sand for construction increased steeply
after the 70s consequent on exponential rise in the number of concrete and tiled houses.
The increasing infrastructure development also enhanced the demand for river sand. As a
result, the annual extraction of sand, on an average, is almost 31 times more than the
annual sand replenishment rate. This, in turn, is lowering the river bed by 5 cm/yr to 18 cm/
yr (CESS, 2006). Increased construction activities enhanced hard rock quarrying. There is
large increase in the number of quarries and rock crushing units, especially in the midland
and highland regions of the State. For example, there are about 20 quarries within a radius
of 4 km and about 50 quarries within a radius of 10 km at a place namely Ayyampuzha near
Angamali (Thampuran et al., 2005). Similar picture exists in the entire western ghat foothill region of the state.
1.2.2.3 State
Beach sand
The IREL and KMML are mining the black sand, accumulated above the mean sea level,
on the beach face. Modern monsoon accumulations of black sand are gathered by power
shovel, and transported by tipper trucks to the stock yard. IREL also has a dredging plant
operating on the ancient beach deposits in the coastal land. The major heavy mineral deposit
in the state occurs between Neendakara and Kayamkulam, covering a total length of 22.5
km and between Kayamkulam and Thottappally over a shore distance of 10 km. Ilmenite
forms the largest constituent of Indian beach sand deposits (~348MT), followed by
!
Land Environment
Sillimanite (~120MT) and Garnet (~107MT). Zircon is only 21MT and Rutile 18MT (AMD,
2001). Keralas share in this regard is 75MT of ilmenite (Chavara 62MT), 12 MT sillimanite,
5MT zircon, 4.85MT rutile, 1.13MT monazite and 0.97MT garnet.
The quartz (silica) sands, also known as Glass sand, are being mined, mainly from
Cherthala area. Large deposits (~42 million tonnes) of pure quartz are available in the
coastal areas of Alappuzha district.
Clay
Kerala has the highest reserve of high grade china clay among all the clay producing
states of India, The clay resource of the state is divided into three, namely a) residual or
primary china clay, b) sedimentary or secondary china clay and ball clay and c) tile and brick
clay. While China clay is generally of Tertiary origin, the tile and brick clay belong to
Quaternary age. The residual clays often contain impurities of siliceous and ferromagnesian
minerals. On the other hand, the sedimentary clays of ball clay variety has organic matter
as impurity.
China clay in Kerala is confined to two southern districts (Thiruvananthapuram and
Kollam) and two northern districts (Kasargode and Kannur), and hence are generally referred
to as Southern Clay Belt (SCB) and Northern Clay Belt (NCB) respectively. While the SCB is
rich in sedimentary china clay (>1952 million tons) derived from Khondalite rocks, the
NCB is predominantly residual china clay (>935 million tons), developed over charnockitic
basement (Directorate of Mining and Geology, 2005). Presently, more than thirty large and
small surface mines are operating in the state. English Indian Clays Ltd. operates a China
Clay mine since 1966 around Thiruvananthapuram, where the processing plant produces
several grades of refined Kaolin (China Clay - both Spray Dried and Rotary Dried), Metakaolin
and Calcined Kaolin (clays) to cater to the paper, paint, rubber, plastic, fiberglass, cement
and ultramarine industries. The plant has a capacity of 190,000 metric tons per annum and
is the largest in South East Asia.
There are several deposits of ball, tile and brick clays in various parts of the state, most
of them are being mined by small private entrepreneurs in the unorganized sector, but for a
few operators making wire cut bricks. The Kerala Ceramics Ltd., instituted in 1963 at
Kundara, Kollam, is one of the leading firms for clay mining and processing with a porcelain
division. There are about 350 tile factories and 5000 brick kilns in Kerala (SPB, 1996). The
tile manufacturing units are concentrated in Feroke (Kozhikkode), Trichur (Trichur), Aluva
(Ernakulam), Chathannur (Kollam) and Amaravila (Thiruvananthapuram.). The annual clay
consumption for making ordinary and decorative tiles, pottery, wire cut and hand cast red
bricks in the five basins of Central Kerala is of the order of 526,650 tonnes (Ramachandran
et al., 2001). There is no production of ball clay in the state.
Land Environment
!!
River sand
River sand is mined extensively from various river basins, from channels and ancient
flood plains for use as aggregate sand and gravel. The unscrupulous mining changed the
physical system of practically all river basins, and disturbed the flora, fauna, hydrology,
groundwater regime and soil. The sand trapped in reservoirs, however, is not exploited in a
large scale. The resource potential of these rivers is depleted significantly, but alternatives
to replace the material are yet to be popularized due to various technical limitations. The
river sand extraction in various rivers is given in Table 1.12.
Table 1.12. Details of river sand mining in certain rivers, Kerala
R ive r san d m inin g d et ails
To ta l
R ivers
A n n ual
sa nd
extr act io n
Mm
3
T ot a l A n n ua l
A n n ual
sa nd
sa n d e xt ra ctio n
b elo w C W C
re p le nis hm
GS
en t
Mm
3
Mm
N o. o f
N o . of
K a d avu s
E xt ra ctio n
L a b our
fo rce
L o ca l
R ve r bed
lo w erin g
to
r ep lenish m
en t rate
B od ies
3
cm / yr
C ha ndr ag iri
0 .515
0 .24
0 .045
35
3
224 2
NA
11
V a lap attnam
0 .648
0.2
0 .065
43
10
282 1
5
10
C ha liy ar
K a dal und i
1 .086
0 .422
0.1 64
0.4 09
0 .077
0 .009
73
90
12
16
472 9
184 0
10
16
14
47
B h ar atha puz ha
1 .426
0.2 71
0 .026
1 53
40
649 4
5
55
C ha lak ud y
0.46
0.2 82
0 .006
45
9
161 9
13
77
P e riy ar
M u v a ttu pu zh a
3.47
0.98
2.0 05
0.5 37
0 .041
0 .013
3 19
2 60
39
35
905 4
492 0
18
7
85
75
M e en ac hil
0.14
0.0 43
0 .004
72
13
104 0
15
35
M a nim al a
Pamba
0.66
0.42
0.1
0.0 95
0 .009
0 .014
1 53
64
19
21
228 6
187 2
12
15
73
30
A c ha nk oil
0 .5
0 .24
0 .006
68
17
203 2
9
83
0.32
0.28
0.1 99
0.1 11
0 .046
0 .004
1 08
65
15
12
358 2
150 0
11
11
7
70
11 .327
4.8 96
0 .365
15 48
261
4 603 1
11
48
K a llad a
V a m a nap ur am
1 4 rive rs
Rock/Laterite
Exposures of different crystalline rocks and laterite cappings are mined for construction
purposes across the state in almost every district. It is estimated that among more than
3000 quarries, some are operated only seasonally while others are abandoned due to various
reasons. Based on a recent survey, a total of 107 quarries and 16 crushing units for
manufactured-sand-production exist in the district of Thiruvananthapuram (Figure 1.14),
i.e., 52 in Nedumangad, 25 in Neyyattinkara, 18 in Thiruvananthapuram and 12 in
Chirayankeezh. Of the 107 quarries, 40 are abandoned. There are six rock crushing units in
Neyyattinkara and four each in Nedumangad and Chirayankeezh taluks.
!"
Land Environment
Figure 1.14. Locations of quarries in Thiruvananthapuram District
Land Environment
!#
Miscellaneous minerals
Gold occurs in Kerala in association with crystalline rocks, laterite and alluvial placer.
The Wayanad-Nilambur and Attappady Gold Belts form the crystalline varieties and they lie
on either sides of Nilgiri massif. The gold of Wayanad and Nilambur belts was worked since
centuries ago from the alluvium and quartz reefs in an unorganized manner. Further, there
are many abandoned gold workings in laterites bearing gold near Nilambur town. The rivers,
Chaliyar and Punnapuzha, host the auriferous gravels, which forms the placer gold formation
of Nilambur. Clandestine activities are still prevalent in these areas.
The gemstones of Kerala occur in three different geological settings namely, the
pegmatites traversing the crystalline rocks, consolidated/lateritised older gravels and within
gravels of modern river channels. Geographically, they can be grouped as (1) Eastern
Madathara-Bonacaud-Neyyar pegmatite field (2) Central Venjarammod-Nedumangad-Vellanad
pegmatite field and (3) Western Balaramapuram-Parassala pegmatite field. The gem bearing
older gravel beds are seen as terraces along the modern river channels. In sections, a
characteristic layer of white to bluish clay with well rounded quartz pebbles is seen above
the gravel layer. In the case of modern channel beds, gemstones are noticed in the Rivers
Kulathupuzha, Vamanapuram, Killi, Karamana and Neyyar.
Lime shell deposits, attaining thickness of 6 to 8m, occur widely in parts of Ashtamudi
and Vembanad lakes, and also in wetlands of Thrissur (Kodungallur, Chavakkad and
Karanchira), Malappuram (Ponnani) and Kozhikkode (Koyilandi, Beypore, Kadalundi and
Elathur) districts. Large deposits of lime shell are also know to occur in the wetlands of
Cannanore and Kasargode districts at Parappuram, Melur, Tellicherry, Baliapatom, Payyannur,
Cheruvathur, Nileswar, Kanjangad and Kasargode. Lime shell reserves available south of
the Thanneermukkom bund and Pathiramanal in Vembanad Lake is of the order of 2.5
million tons. Rich deposits of lime shell is found in the Kulasekharapuram village (2.5lakh
tons) and Pallippuram area (7lakh tons). Deposits in Kozhikkode district is estimated as
4.5lakh tons (GSI, 1976). The lime shell mining from Vembanad lake indicates a declining
trend (Table 1.13).
Table 1.13. Lime shell extraction from Vembanad Lake
Year
1992-93
1993-94
1994-95
1995-96
1996-97
1997-98
!$
Limeshell production (Tonnes)
White shell Black shell Total
104591
30773 135364
100464
33025 133489
93438
33280 126718
109422
26595 136017
88836
30243 119079
85314
29384 114698
Land Environment
The bauxite reserves of the state are spread over an area of 2.36 km2 in Kasargode,
Kannur, Kollam and Thiruvananthapuram districts. Quality wise, the bauxites of Kerala are
of medium grade. The estimated reserve of bauxite is 13.98 million tons with alumina
content of 40% or more. Other deposits of economic significance include iron ore, lignite,
graphite etc. Since no mining activity is currently involved with these deposits, they are not
dealt in detail here.
1.2.2.4 Impact
The impacts, according to Rau and Wooten (1980), can be broadly classified into four
categories, such as impact on land, impact on water, impact on atmosphere, and impact on
socio-economic conditions of the people in the region. The first three impacts are often
categorized collectively as physical / environmental impacts.
The major impacts of open cast or surface mining are modifications of landscape, land
stability and soil loss. Due to continued and unscientific mining, scar like pits of different
dimensions form in the affected areas. Some of the pits may later be filled with water. On
many of the occasions, extensive areas are converted into pools of water. The artificial
ponds created at random locations due to indiscriminate mining may lead to land stability
problems in the adjoining areas and cause accidents. The problem of subsidence will be
aggravated in areas where the subsurface geology is intercalated with sand and clay beds.
Further, impacts on soil due to mining invite loss of fertile top cover rich in N, P, K and other
micro-nutrient elements than subsurface layers. With respect to impacts on water resources,
there could be substantial changes in the surface and ground water sources of the area,
after mining. The abandoned mines, at places, are used for dumping urban solid wastes,
leading to serious water pollution due to the leachates containing organic pollutants and
heavy metals. Dust created during transportation and processing of mined materials and
its settlement in water bodies pose problems to the surface water resource of the area
and neighbourhood.
Mining of china clay
Land Environment
Mining of brick clay
!%
Lowering of water table of the hinterland below normal levels is reported at many places,
where intense clay mining is reported. Dewatering of clay mines to facilitate mining operations
often tends to lower water table and deplete precious groundwater, which affects the
supply sources of several communities in the vicinity. Draining of water from the unaffected
paddy lands into the active mines is another problem that ultimately ends up in the conversion
of paddy lands for other types of cultivation.
Any type of quarrying or reclamation produces only negative impacts on agricultural
landuse, the magnitude of which is proportional to the area under quarrying or to the
extent of area brought under reclamation. The trade-off between the socio-economic needs
and environmental conservation, generally, the former takes the upper hand. In a situation
where competing demands do occur, choice of the most environmentally viable activity is
extremely difficult. There will be marked decline in the aesthetics of the area subjected to
mining. Deaths by drowning are often reported from the mining sites. Further, casualties to
labourers due to collapse of over-hanging earth are also common in poorly-planned excavation
areas. Incidences of caving / slumping of walls of the pits are also reported.
Although all mining activities do not cause any direct change in air quality, transportation
and processing of raw minerals into end products could cause atmospheric pollution. Rise
in suspended particulates, SO2, CO and CO2, are reported from areas around the brick kilns
and tile/brick industries (Shukla, 1981). Studies carried out by Brumsack (1977) revealed
that even some of the toxic metals are released into the atmosphere during the process of
converting clay to brick and other clay articles. According to Pronk (1997), there are even
records of health problems to the people of Thrissur district due to excessive emission of
smoke arising from clustered brick kilns. As far as noise is concerned, clay mining does not
contribute much to noise pollution, except the noise generated from the vehicles that
transport raw clays and the products from the clay-based industrial units. However, air
and noise pollution are significant in hard rock quarrying areas and especially at places,
where rock crushing units are operated.
The chief ecological damages of unabated sand mining are deepening of river bed and
collapse of embankments, lowering of water table in flood plain and aquifers, disruption
and loss of benthic and terrestrial fauna, increased risk for cultural and infrastructural
items. The alluvial sand removal has two components, namely the instream mining and
extraction from paleo-channels, floodplains or paddy fields. Both are equally catastrophic,
in the longer run. Similarly, the random beach mining also invites water table decrease as
well as sea erosion.
In the case of alluvial gold mining at Nilambur, removal of material is an expensive task.
In some sections, the distinction between barren and gold bearing gravel cannot easily be
made. Further, any mining of the alluvial gravel will considerably endanger the channel
walls of rivers, and consequently the neighbouring forests, plantations and fields. The river
!&
Land Environment
Exposed bed rock and foundation of piers in a river due to mining
flow will be modified with possible disturbance occurring in the downstream sections,
vitally affecting the downstream villages. Sociologically, the mining will no way be largely
beneficial to the people living there because they already pan and win gold in small quantities.
The cost of these adverse socio-economic impacts and reclamation is difficult to assess,
but will probably be higher than the value recovered by mining. It may be noted that only
250 kg of gold is estimated from this area.
1.2.2.5 Response
The Mining and Minerals (Regulation and Development) Act, 1957 lays down the legal
framework for the regulation of mines and development of all minerals other than petroleum
and natural gas. The relevant rules in force under the MMRD Act 1957, are the Mineral
Concession Rules, 1960, and the Mineral Conservation and Development Rules, 1988. The
health and safety of the workers is governed by the Mines Rules, 1955. The minor minerals
are separately notified and come under the purview of the State Governments. The State
Governments have for this purpose formulated the Minor Mineral Concession Rules.
Consequent to the economic reforms initiated by the Government of India in 1991 and
on recognizing the need for rapid growth in the mineral sector, the MMRD Act was amended
in early 1994. It permits private investment, both domestic and foreign, for the minerals
that were hitherto considered for exploitation only in the public sector. In accordance with
the amended Act, the Government introduced the provision of Reconnaissance Permit (RP)
for 10,000 km2 per state for a period of three years.
The Government of India brought out Coastal Regulation Zone (CRZ) Notification, 1991
to regulate the development activities proposed in the coastal tracts of India. It has
provisions to regulate mining of minerals in the coastal zone in accordance with a CRZ
status report. The CRZ regulation does not permit mining from the zone between the high
tide and low tide lines. In order to prevent environmental degradation and also to ensure the
Land Environment
!'
incorporation of environmental management measures with a development activity, it is
stipulated that development or modernization activities in the country, depending on their
impact potential, should obtain environmental clearance as per the provisions of
Environmental Impact Assessment Notification, 2006 issued under Environmental
(Protection) Act, 1986. Accordingly, mining of minerals with lease area more than 50 ha
requires environmental clearance from Government of India and if the mining lease area is
less than 50 ha or more than or equal to 5 ha, there is requirement of getting the
environmental clearance from the State Level Expert Appraisal Committee on Environment.
The environmental management plan, mandatory for such clearance, is to ensure safeguards
against environmental degradation.
In order to protect the rivers from large scale dredging of river sand and to protect the
biophysical environment of river systems, Government of Kerala enacted an act namely
The Kerala Protection of River Banks and Regulation of Removal of Sand Act, 2001.
Accordingly, the government formed District Level Expert Committees (DLEC) under the
chairmanship of the District Collector and Kadavu Committees under the chairmanship of
the President of respective Grama Panchayat or Chairman of respective Municipality. The
identification of Kadavus of river banks from where sand removal can be permitted and the
total quantity of sand that can be removed (with due regards to the guidelines of expert
agencies) are regulated by the DLEC. The Act also ensures the supervision and monitoring
of sand removal by Kadavu Committee. The Act envisages the preparation and
implementation of River bank Development Plan for the upkeep of biophysical environment
of a river using River Management Fund, but its progress is very poor.
1.2.3 Soil Erosion
Soil erosion generally takes place due to wind and water. In Kerala, the soil erosion is
mainly due to flowing water and is catalyzed by peculiar land form, soil types, climate and
landuse. Soil erosion results in soil degradation. Consequently, the soil structure breaks,
organic matter content depletes, operative soil depth reduces and plant populations
degenerate. The water erosion is severe and extensive and the sea erosion is episodic and
intense, threatening the life and property of the region. The channel erosion and landslides,
involve spectacular mass displacement and movement. The process of mass displacement
is due to the instability of land mass vis-à-vis gravity, and hence, generally termed as
gravity erosion. The quantum of eroded soil or debris gets transported over land or deposited
in ponds, rivers, reservoirs and lakes or washed down to the sea.
Soil erosion results not only in the loss of soil materials, but also in the loss of soil
nutrients, and soil bio-resources. Loss of soil causes decrease of soil volume over the
bedrock that is available for storage of water and hence will reduce effective water
availability for growth of plants as well as recharge of ground water. Soil flora and fauna
that is abundant in the surface soil and responsible for the fertility and productivity of soil,
also get washed off along with top soil.
"
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The topography of the land plays the most important role in soil erosion as far as Kerala
is concerned. Kerala is a narrow strip of land (width varies from 15 to 120 Km) situated on
the western slopes of the Western Ghat (the Sahyadri). The Western Ghat extending along
the eastern boundary (about 450 Km) is endowed with rich natural resources- soil, water
and bio diversities and covers about two third of the total area of the State. Topography of
the State is characterized by very steeply sloping mountain and hills, rugged and undulating
highlands, steep or moderately steep and undulating midlands and moderately to gently
sloping lowlands. These physiographic zones form nearly parallel belts. In the midland region,
characteristic feature is the presence of a number of laterite hills interspersed with narrow
valleys (Elas paddy fields). The steep slopes in the area facilitate quick run off resulting
in only short duration for infiltration and ground water recharge. Surface flow in such
terrains achieves very high velocity causing soil displacement and movement.
The diversity in elevation is very high in the State, which ranges from below mean sea
level to 2694 m above MSL (Anamudi Peak). The altitudinal characteristics of the central
region of the state are given in Figure 1.15. The low lands are almost level lands (<7.5
MSL) and constitute about 10 % of the total geographic area. The midlands (7.5 75 MSL)
and highlands (>75 MSL) share the rest of the area almost equally and they display moderate
to steep and very steep slopes. Aerial distribution of land in various slope classes is given
in Table 1.14. It indicates that 87% of the land area is characterized by slopes, where
unscientific land use and indiscriminate deforestation will intensify soil erosion.
The soils are erodable to various degrees depending on its characteristics and location.
The general erodability of soil is given in Table 1.15. The major portion of the State is
lateritic and as such is more prone to erosion. This is due to the porous nature and coarse
texture of the soil with medium to low cohesiveness. The erodability of soil in a catchment
Table 1.14. Slope class distribution, Kerala
Category
Level to nearly level
Very gently sloping
Gently sloping
Moderately sloping
Moderately steep
Steep
Very steep
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Slope
(Degree)
0-1
1-3
3-5
5-10
10-15
15-30
>30
Area
(%)
13
24
13
19
20
2
9
"
Figure 1.15. Altitudinal characteristics of Central Kerala Region
"
Land Environment
Table 1.15. Erodability of soils, Kerala
Category
Percentage
None to slight
20
Moderate
69
Severe
4
Area not studied
7
increases with increasing silt content. The sandy soils with less than 4% organic matter
has a minimum erodability factor (K-factor) of 0.02. The silt dominated soils with less than
5% organic matter possesses a maximum K-factor of 0.60. A soil erodability factor varying
from 0.1 to 0.25 can reasonably be attributed to many of the Kerala catchments. It may
generate soil erosion varying from about 9 t/ha/yr to 174 t/ha/yr.
The state enjoys bimodal-tropical-monsoon-climate. The rainfall is of high intensity; of
the order 60 mm/hr. Heavy downpours occur in short spells during the monsoons. The
soils, though with ample infiltration rate, find it impossible to store much intense rain and
excess water runs off the surface in no time, due to the sloping terrain. There are pockets
annually receiving around 6000 mm of rainfall such as Neriamangalam, Mundakkayam and
Vythiri and only 600 mm of rainfall such as Chinnar, a rain shadow region.
Though Kerala has good vegetative cover (Forests, plantation crops, and other agricultural
crops), there are certain areas that lack sufficient canopy cover. Open lands with insufficient
canopy cover are seen in the laterite exposures of the North Kerala. Vegetation cover
offers good protection to soil against erosion and its absence will lead to enhanced soil
erosion.
Destruction of this vegetation either by deforestation or any other processes, is
associated with several undesirable conditions. In the highlands of Kerala with its rugged
topography and heavy rainfall, forests reduce the peak flow and prolong the duration of
flow, thereby reducing surface runoff. Deforestation causes rapid runoff from catchment
areas, as well as frequent flash floods in downstream areas. Traditionally, dispersed linear
settlements developed along the ridges and upper slopes and the intervening valleys between
ridges are used for seasonal agriculture. When annual crops such as cassava are grown in
such deforested land, soil erosion occurs on slopes, which in turn increases the silt carried
by rivers and reduces the storage capacity of reservoirs.
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"!
1.2.3.2 Pressure
The high density of population of the state exerts enormous pressure on the land
resources. The increasing population density led to fragmentation of holdings due to the
shift from joint family to nuclear family added further pressure on land. As a result, natural
vegetation cover reduced significantly, landuse intensity increased appreciably, land
management and soil conservation activities reduced dismally. Fast pace of urbanization
and consequently roads, buildings and such other infrastructure took its share of land.
Agriculture became less beneficial economically and it became difficult for farmers to
afford conservation practices. Soil excavation, land leveling, conversion of paddy fields etc
have reached greater pace and proportions with the introduction of modern machineries.
Soil erosion in the State is extensive and approximately 70% of the total geographical area
is under moderate erosion.
1.2.3.3 State
The erosion status of the state reveals that 83,500 ha is severely eroded, 973,245 ha
is moderately eroded, 1064,879 ha is moderate to slightly eroded, 307,708 ha is slightly
eroded and 620,965 ha is under permanent vegetation and is well protected. It is estimated
that on an average annually about 15-18 tons/ha of soil is eroded from areas where adequate
conservation practices are not adopted. The extent of erosion is given in Table 1.16. A
rough estimate of soil erosion and sedimentation for India reveals that about 5300 million
tones of top soil are eroded annually and 24% of this quantity is carried by rivers as
sediments and deposited in the sea, and nearly 10% is deposited in reservoirs reducing
their storage capacity by 2% (Department of Land Resources, Ministry of Rural
Development).
Table 1.16. Extent of soil erosion (% of the TGA)
Erosion class
Extent(%)
Slight
20
Moderate
70
Severe
4
Every year, various forms of soil erosion such as sheet erosion, rill erosion, channel
erosion, gully erosion, stream bank erosion, sea erosion are causing huge damage to Keralas
economy. The presence of more erodable layers below the topsoil mass works as a causative
factor for landslides. When rainwater seeps into those layers it acts as a lubricant and the
""
Land Environment
top soil mass slides down slope by gravitational forces. Geology, vegetation, topography
etc play vital roles in landslide vulnerability.
The erosion indices based on slope works out to be very high for Kerala. However, the
soil of the mid and uplands are well drained, as porous as sand in many places, and absorb
moderate intensity rainfall without initiating erosion (Jayakumar, 2005). Soils of midlands
and highlands are coarse textured and spheroidal structured. Infiltration rate of different
soils of Kerala are given in Table 1.17. It indicates that soils are capable of permitting
infiltration of moderate intensity rainfall and free drainage; thus resisting runoff to a certain
extent.
Table 1.17. Infiltration rate of certain soils, Kerala
Initial (cm/hr)
After I hr (cm/hr)
Coastal
Alluvium
10.3
5.3
Riverine
Alluvium
8.7
2.3
Red
Loam
6.5
2.1
Forest
Loam
11.3
4.9
Grey
Onattukara
3.4
0.9
Lateritic
4.3
2.2
Thomas et al., (1997) reported that from a teak plantation and a eucalyptus plantation,
the soil loss was found to be 15 t/ha/yr and 46 t/ha/yr respectively. Silt yield reduces
significantly in well managed and protected micro catchments, indicating that land
management measures play a major role in controlling soil erosion (Varma and Abin, 2005).
Unchecked soil erosion will lead to soil and land degradation adding more and more waste
land.
The land degradation status as assessed in 1985 and 1994 and the land degradation in
different types of landuses are given in Tables 1.18 and 1.19 respectively. Areas under
different types of land degradation are given in Table 1.20. The study of KSLUB (2003)
using IRS-IC (LISS-III) data revealed that Kerala has eleven categories of wastelands (Table
1.21). The distribution of different types of waste land in the State is given in Figure 1.16.
The Soil Conservation Unit under the Department of Agriculture is implementing soil
conservation schemes in the State. Besides, soil conservation schemes are taken up under
various watershed development projects. According to an Evaluation Study by the State
Agricultural Finance Corporation, the total area where soil conservation measures have
been taken up till 2005-06 is 3.85 lakh ha. The silt entrapped is 13.45 t/ha/yr and the
water conserved is 6814 m3/ha/yr. Subramaniyam (1993) reported that out of the estimated
total area of 174.96 million ha affected by soil erosion and land degradation, so far about
35 million ha has been treated during the last four decades leaving a remaining area of 140
million ha unattended.
Land Environment
"#
Table 1.18. Status of land degradation, Kerala (1985 & 1994)
(Area in Lakh ha)
1985
% Geo Area
Type of Degradation
Soil Erosion
(a) Water
(b) Wind
Ravines
Saline
Sodic
Waterlogged/Marshy
Mine & Quarry Wastes
Shifting Cultivation
Degrade Forests
Special Problems
A-Acid Sulphate
S-Sandy Waste
C-Chos
T-Torrents
LS-Land Slide
Total
1994
% Geo. Area
15.77
1.17
0.61
1.8
-
40.6
3
1.6
4.6
-
9.52
0.01
0.76
1.98
0.01(s)
24.5
neg
2
5.1
neg
19.35
49.8
12.28
31.6
(Source: Dft. Rep. Status of Land Degradation in India. Dept. of Agriculture &
Co-operation, Govt. of India).
Table 1.19. Category-wise land
degradation, Kerala (2003)
Category
1.Soil erosionMod. to severe
2.Control
water
logging
3.salinity
4.Degraded forest
5.Semi stream bank erosion
6.Land slides
7.Sea erosion
Total
&
(Source : SPB, 2005)
"$
Area (Lakh
Ha)
9.52
0.76
1.98
1.00
1.00
0.50
14.76
Table 1.20.Various types of land degradation and Wastelands, Kerala
1 Water erosion
Area
(lakh Ha)
23.12
2 Wind erosion
0.00
3 Physical deterioration
0.00
4 Chemical deterioration
0.00
5 Other problems- Nutrient loss
2.96
No
Types of Land Degradation
Total
26.08
Per cent of Total Geographical Area
45.6
(Source : NBSS & LUP, Bangalore)
Land Environment
TY PE S OF W A S T E L A ND IN K ER A L A
L an d wit h/w ith ou t scr ub
W at er log ged /M a rsh y land
D e gra de d n ot ifie d fore st
la nd
D e gra de d p as tu res /g ra zing
la nd
D e gra de d la nd un de r
p lan tat ion
S a nds -Inla nd/ C oas ta l
M in ing/ Indu st ria l w ast e land
B a rr en ro ck ar ea
S t eep s lope a re a
(Source: Wasteland Atlas of India, 2000)
Figure 1.16. Distribution of different types of waste land
1.2.3.4 Impact
The severe soil erosion resulted in reduced soil fertility and productivity, and crop
production became less remunerative. According to the reports of National Sample Survey,
Kerala farmers are among the most indebted in the country (Anon, 2006). A number of
environmental problems have developed as a result of erosion related problems. Floor Anthoni
(2000) brought out some important issues as listed below:
•
Loss of land: the top layer of productive land is washed away.
•
Loss of crop/pasture: crops and pasture are destroyed due to wash out or covered
by mud.
•
Reduced yields: flooded fields may take a long time to recover; wash out of fertilizers
•
Damage to structures: roads, fences, bridges, trees, houses etc get damaged,
needing costly repair, often when cash flow is at its lowest (in winter).
•
Down-stream damage: neighboring fields may receive an unwelcome load of soil
and mud, rivers silt up and river banks erode.
Land Environment
"%
•
Flooding: floods over cropland destroy crops, kill animals, damage houses. Fields
become waterlogged with fine silt.
•
Coastal marine damage: silt and mud settle on the bottom, killing bottom-living
organisms. Dirty water suffocates filter feeders like sponges, sea squirts and clams.
Nutrients from mud and fertilizers cause excessive plankton blooms which turn
poisonous, killing fish and upsetting mariculture of mussels, oysters and scallops.
Seaweeds die through lack of light.
Table 1.21. Types and extent of waste lands, Kerala (After KSLUB, 2003)
Sl. Category of wasteland
Area
No.
(km2)
1 Land with scrubs
691.12
2 Land without scrubs
2.91
3 Waterloggedpermanent
20.27
4 Waterlogged seasonal
248.49
5 Under-utilized/degraded
432.77
notified forest land
scrub dominated
6 Degraded pastures/grazing 117.26
land
7 Degraded land under
51.54
plantation crop
8 Coastal sand
11.55
9 Mining
2.18
10 Barren rocky/stony
193.48
waste/sheet rock
11 Steep sloping area
17.56
Total
1789.15
%
38.63
0.16
1.13
13.89
24.19
6.55
2.88
0.65
0.12
10.81
0.98
100.00
The studies carried out in teak plantations indicated that input of 32710 m3/ha of water
from rainfall leads to a surface run off of 8310 m3/ha resulting in the N loss of 17 kg/ha and
K loss of 2.3 kg/ha. Similarly in eucalyptus plantations, a surface run off of 5675 m3/ha
resulted from the input of 29575 m3/ha of water from rainfall leads to the N loss of 52 kg/
ha and K loss of 8 kg/ha (Thomas et al., 1997). Erosion of the topsoil also leads to reduced
soil quality and low productivity over time. Some of the landslides in Idukki District during
recent years are thought to be the result of deforestation, changing cropping patterns and
soil disturbance. (Varma, 2005) compiled the sedimentation rate of certain reservoirs in
Kerala to highlight the impact of siltation consequent to soil erosion (Table 1.22).
"&
Land Environment
Table 1.22. Sedimentation rate in selected reservoirs, Kerala
Sl. No.
Reservoir
Year of Catchment area
survey
(km2)
1
2
3
4
5
6
7
8
Sholayar
Poringalkuthu
Peppara
Neyyar
Mangalam
Peechi
Malampuzha
Peruvannamuzhi
2002
175.8
2002
692.5
2001
86.00
1997
140.00
1985
48.55
1985
107.00
1990
47.63
1986
108.8
Mean annual storage loss
Gross
capacity
(Mm3)
153.00
32.00
38.40
106.19
--228.40
--
Live
capacity
(Mm3)
150.00
30.00
29.76
77.40
24.67
109.00
-113.45
Annual
storage
loss (%)
0.29
0.55
1.32
0.71
0.30
0.97
0.25
1.66
0.76
1.2.3.5 Response
In order to spearhead the activities for protection and conservation of soil, the
Government of Kerala is implementing integrated watershed development projects through
the Department of Agriculture, Rural Development and Western Ghat Cell for more than a
decade. There are also non-governmental organizations involved in watershed development
programmes. The Department of Agriculture has constituted two technical wings for soil
survey and soil conservation under it with independent entity. The soil survey organization
is providing the baseline information on watersheds for identifying and prioritizing microwatersheds to be treated. The soil conservation unit organizes the implementation of
agronomic and engineering measures.
One of the centrally sponsored schemes that was extended to many districts was the
National Watershed Development Programme for Rainfed Areas (NWDPRA), a programme
for promoting desirable landuse and soil conservation. This was implemented through the
panchayat level agricultural offices. Another major centrally sponsored project taken was
the Integrated Wasteland Development Project, especially in the districts of Kasargode,
Wayanad, Malappuram and Palakkad through the Department of Rural Development with
the objective of land and water conservation and development and employment generation.
Various watershed development programmes are also taken up under Western Ghat
Development Programme (WGDP), Rural Infrastructure Development Fund (RIDF), HARIYALI
etc.
Most of the watershed projects failed to generate sustainability because of the failure
of Government agencies to involve the people. Both Government departments and NonGovernment organisations (NGO) have been pursuing development activities quite
independent of each other. NGOs tend to work more as independent implementers than as
catalysts for bridging the gap between local people and the state. During the 9th Five year
Land Environment
"'
plan period, a massive campaign, as part of Peoples Plan Campaign for Decentralized
Governance was launched to prepare Watershed based Development Master Plan for each
micro-watershed in the State. As a result, Watershed Appraisal Report was prepared for
152 Blocks of the State, which was handy in preparing watershed based development
programmes in subsequent years.
However, there is a need for greater coordination and integration of these programmes
ensuring informed participation of the local governments as well as people. The recent
National Employment Guarantee Scheme largely replaces the various earlier schemes for
water and soil conservation and afforestation. As part of the 11th Five Year Plan, Local
Self Government Institutions aim to develop comprehensive watershed programme by
scientifically reviewing each small watershed through peoples participation. It is proposed
to convert the watershed programme into a massive public movement by lining up farmers,
agricultural labourers and volunteers. It will be beneficial only if the above mentioned different
schemes are integrated and implemented based on such a blue print.
1.2.4 Soil Quality Deterioration
Soil quality ,defined as the capacity of a specific kind of soil to function, within natural
or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or
enhance water and air quality, and support human health and habitation is an important
tool for evaluating and understanding the effects of soil management on a specific soil
resource. The health of a soil is largely defined by soil functions and represents a composite
of its physical, chemical and biological properties. The basic functions of soil are:
•
Sustaining biological activity, diversity, and productivity;
•
Regulating and partitioning water and solute flow;
•
Filtering, buffering, degrading, immobilizing, and detoxifying organic and inorganic
materials, including industrial and municipal by-products and atmospheric deposition;
•
Storing and cycling nutrients and other elements within the earths biosphere; and
•
Providing support of socioeconomic structures (i.e. buildings, roads) and protection
for archeological treasures associated with human habitation
Soils are essential for food production, storage and filtration of water and nurturing
multitudes of species by providing a habitat. Therefore, environmental upkeep of soils is
fundamental. The threats to soils are accelerated by industry, mining and farming, waste
disposal etc. Other threats are soil sealing, essentially due to paving and concreting of
roads, building premises, play grounds, runways etc., which greatly reduces the available
soil cover that facilitates seepage of rainwater.
#
Land Environment
Soil is a life support system to be perpetually kept in a stage of high productivity.
Geologic, geographic, climatic, topographic, biologic and anthropogenic factors either enhance
or inhibit soil health and productivity. Extensive deforestation, intensive cultivation and
unscientific developmental activities in the state resulted in destruction of natural
ecosystems, accelerated run off, soil loss along with nutrients, hydrological degradation
and productivity loss. Waste disposal from industries and mines, excessive and injudicious
use of pesticides and fertilizers, urbanization etc., aggravates soil contamination leading to
soil quality deterioration.
The industrial growth in Kerala, though much lower compared to rest of India, has led to
the establishment of 640 large and medium industries and about 2.5 lakh small scale
industrial units (Viju et al., 2005). These industries generate waste in solid and liquid form
which are mostly disposed or discharged in to adjacent land in the absence of appropriate
waste management systems. There are about 133 industries under major and medium
category, distributed in 13 districts, generating hazardous waste to the tune of 82,726 t/
yr (Vijayabhas et al., 2005). In addition, 290 small industrial units also produce hazardous
waste. The coir units in the state itself generate about 500 t/yr of solid wastes out of
which about 143 t/yr is of hazardous nature as a result of dyeing and bleaching facilities
attached. There is lack of appropriate disposal mechanism for the hazardous waste produced
by many industrial units. In addition, there are a number of automobile service stations and
vehicle repair shops, producing waste oil and grease that ultimately find their way to soil.
The over use of chemical fertilizers and pesticides are on the rise and widespread,
especially on account of expanding plantation and fruit crops. The consumption of chemical
fertilizers in the State during 2001-02 is reported to be 177,125 tones (Directorate of
Agriculture, 2003). The quantity of pesticides, weedicides and fungicides applied in Kuttanad
is of the order of 485 t/yr. The indiscriminate application of such chemicals affected the
soil health.
Due to urbanization and consequent change in life style, the domestic solid waste volume
is increasing appreciably (Table 1.23). The prediction is that the waste generation will
reach 9300 t/d by 2006. Almost 50% of the waste in the urban area goes uncollected
from the road sides and other places of dumping, where it is putrefied and leach to the soil.
The waste collected is also mostly disposed of in the open in municipal collection centres
and dumping yards in the absence of an appropriate waste recycling, reuse or recover
facilities. The situation in the Grama Panchayaths is also poor, largely in the absence of a
suitable waste management system.
1.2.4.2 Pressure
Intensive cultivation, often with incorrect crop and soil management practices, give rise
Land Environment
#
Municipal solid waste dump at Vilappilsala
Table 1.23. Domestic solid waste generation in 2001, Kerala
Total Population
2001
5 Corporations
53 Municipalities
999
Panchayaths
Total
2456618
5810307
23574449
Per capita
Waste
Generation (g)
400
300
200
Total Waste
Generation(t/day)
983
1743
4715
7441
(Source: SEUF, 2006)
to heavy loss in soil quality. Organic or green manure application is grossly neglected in the
recent years primarily owing to its cost factor and scarcity. This gave rise to alterations in
soil structure, which in turn led to changes in all other soil quality attributes. Moreover,
#
Land Environment
excessive or imbalanced application of chemical fertilizers had its share in protracting the
problem of acidification in the arable soils. At the same time, practices like liming, which
can rectify acidity, are not given enough concern, again due to the scarcity of the liming
material, and hence the ability of soil to sustain agriculture decreases. As soil acidifies, its
buffering capacity lowers as base cations such as magnesium and calcium, both essential
plant nutrients, are leached from the soil. As acidification proceeds, metals, including
aluminium which is toxic to plant growth, get accumulated. Nitrogen deposition also
contributes to soil and water eutrophication, as well as to acidification. Even though, nitrogen
is an essential plant nutrient, excess inputs can contribute to soil eutrophication.
Extensive deforestation together with unscientific forestry practices has paved way
for huge quantities of soil loss through erosion from the up lands to lower areas. In these
places, loss of the fertile top soil has totally altered quality aspects of soil leading to severe
deterioration in soil properties. Considerable decrease in effective soil depth interferes
with the rooting and anchorage of plants. The transportation of soil from the upper reaches
and its settlement in the lower valleys or water bodies changes the physical properties
such as infiltration rate and water holding capacity, chemical properties such as pH and
biological properties such as microbial activity and enzyme activity, affecting soil biodiversity.
Wastes contain potential contaminants including heavy metals, organic compounds and
pathogens which damages soil quality. Heavy metals such as cadmium, chromium, copper,
mercury, nickel, lead and zinc occur naturally in soil at levels dependent on soil parent
material. Many are essential to living organisms in trace concentrations. Waste dumping
on ground can cause elevated concentrations of metals, adversely affecting soil processes.
The haphazard disposal of solid wastes by industries, in the absence of proper waste
management facilities enhances the adverse impact on soils.
Pesticides used in agriculture include insecticides, fungicides, herbicides, growth
regulators and seed treatments and comprise a wide range of chemicals. Pesticides can
enter watercourses, damaging aquatic ecosystems and polluting drinking water. Two major
pesticides reported in Kerala environment are Hexa Chlorocyclo Hexane (HCH) and
Endosulfan. HCH introduced to the environment from industrial discharges, insecticide
applications or spills may cause acute toxic effects including the death of animals, birds, or
fish, and death or low growth rate in plants (Bunton 1996; Smith, 1991). The insecticide
load in surface waters does not ordinarily reach concentrations acutely toxic to aquatic
fauna. However, lindane, a gamma-isomer of HCH, has high chronic toxicity to aquatic life.
The effects of low insecticide concentrations often appear only after relatively long exposure
times. Chronic exposure to lindane can be hazardous to freshwater macroinvertebrates
even at unexpectedly low concentrations (Schulz et al. 1995). Such low-concentration
effects may depend on both species and substance and therefore cannot be predicted from
toxicity data at higher concentrations. Manufacture and usage of lindane continues in
Land Environment
#!
numerous countries, and production of technical HCH is suspected to be continuing in
some parts of the world. Li (1999) concluded that India, was probably the most heavily
contaminated country with respect to environmental levels of HCH.
The pesticide, Endosulfan, is persistent in the environment, with a half life of several
years in soil. It may accumulate in the bodies of fish and other organisms exposed to
endosulfan contaminated water. The main source of human exposure to endosulfan is via
ingestion of food that contains this pesticide as a result of direct pesticide application or
bio-concentration (ATSDR 1997). Endosulfan may be lethal to humans and animals by
inhalation, oral or dermal exposure. The main target is the central nervous system. In
studies on experimental animals, damage to the liver, kidney, gastrointestinal, haematopoietic
and dermal systems and developing foetuses have also been demonstrated following
exposure to endosulfan (ATSDR 1997).It is recognized, that agricultural production relies
on such inputs and that a balance needs to be struck between sustaining agriculture
economically and changing land use practices.
Uncollected waste and that dumped indiscriminately on the road margins are a direct
burden on public health and environment. Though the producers of waste are made
responsible to segregate the waste into biodegradable, non-biodegradable and domestic
hazardous and store at the place of generation for delivering it to the municipal stream, it is
yet to become a habit and practice. Similarly, the municipalities are made responsible for
collection, transportation, processing and disposal of waste, the preparedness so far is
poor. In order to reduce the environmental pollution due to domestic solid wastes, it is
mandatory to segregate and store the waste at source, collect the waste from source and
transport it to the processing facility, process the waste for recovery and dispose the
residues safely. However, these are not practiced regularly, leaving the wastes for
putrefaction on road sides and public places. The sanitary practices are mostly ignored by
civic authorities leading to soil contamination and water pollution. Figure 1.17 indicates the
poor level of such environment friendly practices in comparison to national level.
1.2.4.3 State
Even though Kerala occupies only 1.18 % of the total geographicl area of India, it has a
variety of soil types (Figure 1.5) owing to varied topographic features, high rainfall and
geologic conditions. As a consequence, the soil properties also vary widely. But almost 70
% of the area is covered by laterite and associated soils and hence properties inherent to
these soils can be considered as fairly representative of the whole State (KAU, 2000).
Assessment of soil quality through a Minimum Data Set as detailed below, presents a
dismal picture of the status of soil quality in the state. Almost all the parameters evaluated
indicate soil degradation at different stages which needs immediate intervention.
#"
Land Environment
Figure 1.17. Compliance status of waste management practices, Kerala
A) Physical
a) Texture and Structure
The relative proportion of mineral particles of different sizes (sand, silt, clay), which is
designated as texture and the size, shape, and arrangement of these particles, designated
as structure are key factors in soil quality. The texture of Kerala soils ranges from sandy
to clayey (Table.1.24). In the coastal area, the soil texture, especially of the garden lands,
indicates two separate zones, one with sandy loam and the other with sandy soil. In laterite,
which is the major soil type, it varies from sandy loam to sandy clay loam (Antony, 1982).
This soil mainly consists of Low Activity Clays which are susceptible to crusting due to
impact of rain drops, thereby causing intense run off and erosion. The black soils of Chittoor
are clayey in texture which form hard mass that cracks on drying and turn sticky on
wetting, making the soil impervious. Soils of Orumundakan and kaipad lands contain coarser
fractions compared to pokkali lands. The very high gravel content of laterite soils ranging
Land Environment
##
Table.1.24 Texture and structure of the different soil types of Kerala
Soil
Texture
Structure
1.
Laterite
Sandy loam to sandy
clay loam
Weak granular to moderate sub
angular blocky
2.
Forest
Sandy clay loam to
clay
Weak granular to moderate sub
Angular blocky
3.
Red loam
Weak granular
4.
Coastal alluvium
Sandy loam to sandy
clay loam
Sandy to loamy sand
5.
Kuttanad (acid saline) Silty clay loam to clay
Massive
6.
Clay loam to clay
Massive
7.
Hydromorphic saline
Pokkali & Kaipad
Kole
8.
Black
Sandy loam to clay
9.
Grayish Onattukara
Loamy sand
Medium to coarse subangular
blocky
Weakly coherent, massive
10. Riverine alluvium
Sandy loam
Structureless
11. Brown hydromorphic
Sandy loam to clay
Massive
Weak granular
Silty clay loam to clay Moderate, medium subangular
blocky
from 30 80 % and the varying depths of laterite bed, causes serious root zone limitation
(Venugopal, 1980). This is a serious concern as the crops are mostly perennials. Both
gravel and laterite pan are absent in the associated red soils.
Majority of the Kerala soils exhibit a weak granular to moderate sub angular blocky
structure, with certain patches exhibiting a massive structure. This shows that the soil
binding agents are not very active in these soils (Table.1.24). Maintaining good soil structure
is essential to sustaining long-term agricultural productivity. Good structure implies that
the state and stability of aggregates do not limit a crops yield potential, that the soil is
suitable for maximum root growth and penetration, and that the soil is stable against forces
causing soil degradation.
The intense cultivation in the midland region and faulty agro techniques of slope cultivation
especially tapioca has depleted the surface soils and along with it organic matter and plant
nutrients (Venugopal, 1980). The removal of the soil column exposes the laterite bed which
on exposure to air and prolonged dry conditions promotes dehydration and crystallization of
the iron hydroxides, resulting in the formation of iron stone petroplinthite. The process is
irreversible and makes such areas unsuitable for any cultivation. Extensive areas of
#$
Land Environment
petroplinthite formation are the characteristics of the laterite landscape in Calicut,
Malappuram and Kannur districts of Kerala. These areas are designated as waste lands
(KSLUB, 1989).
Organic matter has an important role in maintaining good soil structure. The granular
structure which is considered ideal for cultivation is built by the activity of the soil organisms
which will mix the organic matter and soil particles together with the glue-like substances
excreted by them. Deviations from the ideal indicate deteriorating soil structure which
increases the risk of soil erosion. Soils that have weak and unstable aggregates are the
most susceptible to accelerated structural damage. This emphasizes the need for better
management options like higher rates of incorporation of organic matter so as to prevent
further deterioration in soil quality.Bulk Density (BD) and Water Holding Capacity(WHC)
b) Bulk Density (BD) and Water Holding Capacity(WHC)
Bulk density, defined as the weight of soil per unit volume is a fundamental soil property
which is used as an important site characterization parameter since it changes for a given
soil. It is also essential in interpreting nutrient budgets and calculating soil porosity. BD of
the Kerala soils varies from 0.9 to 1.7 Mgm-3 depending on the locations (Table.1.25).
Heavy soils pose a threat to cultivation making root penetration difficult. In the laterite
soils where the hard laterite pan is observed, sometimes higher values of 1.8 Mgm-3 have
been recorded, even though it ranges from 1.27 to 1.35 in general.
WHC which directly reflects the water storage and drainage capacity also shows wide
variation ranging from 21.5 % to 50 %. The lesser soil volume because of high gravel
content in the laterite soils leads to lesser available water holding capacity and hydraulic
Table 1.25. Bulk density and WHC of Kerala soils
Soil
1. Laterite
2. Forest
3.Red loam
4.Coastal sandy
5.Kuttanad(Acid saline)
6.Hydromorphic saline
Pokkali & Kaipad
7. Kole
8. Black
9.Greyish Onattukara
10.Riverine alluvium
11.Brown hydromorphic
Land Environment
BD(Mgm-3)
1.27 1.35
1.07 1.24
1.17 1.71
1.59 1.62
0.94 1.35
1.26 1.30
WHC (%)
29.7-50.1
31.5 51.8
21.5 47.5
18.2 20.5
35.4 61.3
49.5 51.0
0.86 1.41
1.20 1.79
1.43 1.64
1.35 1.42
1.25-1.45
41.1 86.1
60.3 71.2
19.6 21.2
40.6 44.6
42.5- 45.3
#%
properties which leads to rapid movement of water. The low WHC of the kaolinite clays
also leads to poor water availability in the root zone of most of the crops especially during
summer months. The above values indicate that these properties have to be modified
favourably by suitable soil conservation methods for improving the air: water relations in
soils.
c) Effective soil depth and Water Table depth
The effective depth of a soil for plant growth is the vertical distance into the soil from
the surface to a layer that essentially stops the downward growth of plant roots. The
barrier layer may be rock, sand, gravel, heavy clay, or a cemented layer. Plants growing on
shallow soils have less mechanical support than those growing in deep soils. Trees growing
in shallow soils are more easily blown over by wind than are those growing in deep soils.
ESD, in general, shows wide variation from shallow to very deep (Table.1.26). Laterite
soils which is the major soil type in Kerala also shows wide variation in ESD ranging from
50 cm (shallow, in some locations in Malappuram district) to 150 cm (very deep, in
Trivandrum district).
Table.1.26. Effective Soil Depth and Water Table Depth
Soil
1. Laterite
2. Forest
3.Red loam
4.Coastal sandy
5.Kuttanad(Acid saline)
6.Hydro saline Pokkali&Kaipad
7. Kole
8. Black
9. Onattukara
11.Brown Hydromorphic
Effective Soil Depth
Shallow to very deep
Deep to very deep
Very deep
Very deep
Shallow
Shallow
Shallow to moderately deep
Moderately deep
Deep to very deep
Moderately deep
Moderately deep to deep
Water table depth
15 30 m
>20m
>25 m
> 3m
Submerged to <1m
Submerged to <1m
Submerged to <1m
<1m
125 cm
<2m
<2m
The water table depth is very important as far as plant growth is concerned. Shallow
water table will interfere with the root activity by restricting aeration and thereby growth.
If it is very deep, dearth of water will limit plant growth. In Kerala soils water table fluctuates
from < 1 m (in kari, pokkali soils) to >25 m (in red loam) (Table.1.26). The places with
excessively shallow soil and water table need special attention for proper management.
#&
Land Environment
25
45
25
5
air
wa ter
mi neral ma tter
org anic mat ter
Figure.1.18. Components of soil
B) Chemical
a) Soil organic matter content
The quantity of organic matter in a soil is a major indicator of its quality. Although soil
organic matter comprises only a small fraction of the total mass of most soils, this dynamic
soil component influences soil properties to an extent far out of proportion to the small
quantity present.
It acts as a reservoir of plant nutrients, maintains soil structure and improves the
overall quality of the soil. Maintaining a sufficiently high level of quality organic matter is
therefore one of the most critical objectives of soil management for improving physical
(structure), chemical (nutrient availability) and biological (soil flora and fauna) properties of
soils.
The status of SOM is generally low to medium in majority of the soils even though
variation can be found in soil types depending on the location. A low level of organic matter
is characteristic of red and laterite soils consequent to the high mineralization rate. Kari
soils are having a high status of organic matter where as laterite soils generally are poor in
SOM. Soil Organic Carbon (Figure 1.19) which is a direct measure of SOM ranges from
0.11 % (in laterite) to 17.5 % (in kari) (KAU, 1994). Laterite soils are generally devoid of
decomposing or partially decomposed organic matter.
Land Environment
#'
25
20
15
10
5
yd
ro
m
h
u
n
w
br
o
e
ri
ve
ri
n
on
at
tu
k
al
lu
vi
ar
a
k
ac
bl
le
ko
po
t ta
n
kk
al
ad
y
d
ta
l
co
as
re
ku
lo
d
sa
n
am
st
re
fo
la
t
er
it
e
i
0
H i g he s t
Lo w e s t
M e an
Figure 1.19. Organic carbon content (%) of Kerala soils
The Kari soils are rich in fossil organic matter at different stages of decomposition.
Occurrence of Kari soils in isolated patches can readily be distinguished by their deep black
charcoal colour which is due to high organic matter content. Top soil contains well decomposed
organic matter in the range of 10 30 %. But very often this layer is underlain by partially
decomposed fibrous plant residues containing less than 50 % mineral matter. Soils of
some of the regions are called muck or peat soils purely on the organic matter content and
its degree of decomposition. Organic carbon content of soils of different locations varies
widely ranging from 5.35 to 17.5 %. Organic mater in kari soils is largely of ligno-protein
complex consisting of large quantities of lignin, ether and alcohol soluble substances and
other resistant fractions of organic matter. In black soils of Chittoor, the soil surface is
rich in partially decomposed organic matter which exhibits a highly colloidal nature.
SOM, which is primarily related to climate, has a pivotal role in controlling and modifying
the physical, chemical and biological properties of soil. The data shows that the Kerala
soils have to be managed with frequent addition of good quality organic manures so as to
maintain a constant moderate level of SOM to make the soil more fertile.
$
Land Environment
(b) Acidity (pH)
Soil reaction, an indication of the alkalinity or acidity of soil, acclaims paramount
importance among the chemical and the electrochemical characteristics that influence soil
fertility and crop production. Soil reaction is determined by the measurement of pH.
All soils except the black soils of Chittoor are acidic in reaction showing a pH of less
than 6.5 (Varghese, 1973). The humid tropical climate with high rainfall, acid parent material
and high rate of organic matter decomposition favour the formation of acidic soils in Kerala.
Extreme acidity is observed in the Kari soils of the Kuttanad region. The pH of air dried
samples in Kari soils ranges from 2.8 to 5.3(Varghese and Aiyer, 1973). In wet samples a
higher pH is observed than dry samples. Seventy five percent of Kari soils register a pH
below 4.5. Seasonal fluctuations are observed in pH of Kari soils. The highest pH is noted
in October November, while the lowest in March April (Padmaja et al, 1994).
Kari soils are affected by periodic saline water inundation with consequent accumulation
of soluble salts. In these soils, free sulphuric acid is formed by the oxidation of sulphur
components of organic residues or that accumulated in the soil from seawater by repeated
inundation (Thampatti, 1997).Among exchangeable cations, H dominated and occupied about
75 to 80 % of the exchange complex. pH of the soil increased with depth. Air drying
increased the intensity of acidity mainly due to oxidation of sulphur compounds of the soils
of the upper horizons but the lower layers turned to neutral or alkaline. Dissolution of Ca
CO3 in the form of lime shells which are mostly seen in the lower horizons neutralize acidity
and change the pH to neutral or alkaline.
Table.1.27. Values of pH and EC of Kerala soils
Soil
1. Laterite
2. Forest
3.Red loam
4.Coastal sandy
5.Kuttanad (Acid saline)
6. Hy.saline (Pokkali & Kaipad)
7. Kole
8. Black
9. Onattukara
10. Riverine alluvium
11. Brown Hydromorphic
pH
4.6 5.5
4.8 5.2
4.5 5.4
5.2 6.5
2.8 5.3
3.3 6.0
2.8 5.7
6.3 8.3
5.2 6.5
4.7 5.6
5.0 5.5
EC (dSm-1)
0.02 0.09
0.01 0.04
0.01 0.10
0.04 0.09
2.3 3.95
1.5 20.0
0.16 15.0
0.13 0.36
0.04 0.09
0.02 0.016
0.01 0.04
(Source: Soil Survey Organization, Kerala,,2007)
Land Environment
$
The acidity characteristics of the wet lands of Kerala shows that major part of potential
acidity is constituted by non exchange acidity (pH dependent acidity) because pH dependent
changes are more in Kerala soils owing to the predominance of kaolinite and sesquioxides.
The highest exchange acidity is noticed in Kari soils followed by Pokkali and the least in
black soils (Table.1.28). Path coefficient analysis of important acidity contributing factors
and the correlation and regression analysis of soil characteristics indicated that exchangeable
aluminum was the best parameter for measurement of acidity (Usha and Varghese,1997).
High dose of lime application causes reacidification of soil at a faster rate especially in
soils having high potential acidity. But if submerged, all the wetlands except the acid
sulphate soils will attain a pH around 5.5 within two weeks, which will not pose a problem
for rice cultivation. Polder cultivation with low rates of lime after maintaining 10cm water
Table. 1.28. Characterization of acidity in major wetlands of Kerala
Name of wetland
Vellayani-Tropic
Fluvaquent
Karamana-Typic
Tropaquent
Kari(Thakazhi) -Typic
Sulphaquent
Karapadom(Nedumudi) Aeric Tropaquept
Kayal(D Block) -Typic
Hydraquent
Pokkali(Njarakkal) Sulphic Tropaquept
Kole(Anthikkad) -Typic
Tropaquept
Kaipad(Pazhayangadi) Tropic Fluvaquent
Pattambi-Aeric
Kandiaqult
Kattampally-Tropic
Fluvaquent
Wynad-Typic
Tropaquent
Chittoor-Petrocalcic
Calciustert
Active
acidity
Dry pH
1:1(H2O)
Exchange
acidity
cmol(+)kg-1
Non exchange
acidity
cmol(+)kg-1
Potential
acidity
cmol(+)kg-
4.35
1.58
17.42
19.00
5.28
0.41
13.59
14.00
3.20
16.40
113.65
130.05
4.31
3.31
32.59
35.90
4.44
4.93
36.67
41.60
3.18
8.03
33.17
41.20
4.63
1.38
28.62
30.00
5.27
0.69
15.00
15.69
4.93
0.49
18.81
19.30
5.46
0.16
19.63
19.79
4.83
0.34
12.86
13.20
6.99
0.12
19.13
19.25
1
(Source: Usha, 1995)
$
Land Environment
level is recommended for economic returns from Kari and Pokkali lands. Subsurface tile
drains are used to remove acidity as well as salinity (KAU, 1998). Keeping the soil under
submergence as for as possible was found to be the best remedy for these soils. They did
not require lime to raise the pH for rice cultivation.
But studies conducted with upland crops have shown that they respond to lime application
(KAU, 2005). This points to the need for ameliorative practices like application of lime in
upland cultivation and submergence in low lands.
(c) Electrical Conductivity(EC) and salinity
EC is the direct measure of the salt content in a soil. In Kerala, only the black soils of
Chittoor are neutral to alkaline in reaction, all others are acidic. But sea water inundation
poses serious problems in Kari, Pokkali, Orumundakan and Kaipad lands which exhibit EC
values higher than 4 dS m-1 which will interfere with plant growth.
Most of the coastal land, deltaic areas at river mouths and reclaimed back waters are
either at sea level or 1 1.5 m below MSL. This leads to intrusion of sea water upto a
distance of 10 20 km upstream during high tides. These periodically inundated lands
constitute the major saline soil areas of the state. Based on location, extent and intensity
of salinity, three types of saline soils are recognized in Kerala. They are
1.
Pokkali lands known after pokkali type of cultivation; located between
Thanneermukkom and Enamakkal bunds i.e. in the coastal areas of Ernakulam and
Thrissur districts mostly distributed in Cochin, Kanayannoor,
Paravur,Thrissur and Kodungallur taluks.
2.
Orumundakan lands of Alappuzha and Kollam districts, known after the long
duration variety of rice grown there, distributed mostly in Cherthala and
Ampalapuzha taluks.
3.
Kaipad lands of Kannur district, situated in the low lying deltaic areas of river
mouths.
The different types of lands described above constitute an area of about 30000 ha.
Pokkali, Kaipad and Orumundakan lands are cropped with paddy once in a year from JuneJuly to Oct Nov when the salinity level in the surface soils is brought below the critical
level of less than 4 dSm-1 for the saturation extract of the soil, by monsoon showers. Soils
of pokkali lands are deep, dark bluish black in color, impervious and clayey in texture which
form hard mass which cracks on drying and turn sticky on wetting. Soils of Orumundakan
and kaipad lands contain coarser fractions compared to pokkali lands. Sea and backwater
tides make these soils saline. During monsoon season when rainwater and fresh water
from rivers enter the field, salinity is partially washed off. Under these conditions the
inherent acidity of these soils becomes more dominant (Padmaja et al, 1994).
Land Environment
$!
A comparative study of the seasonal variation in salinity and pH in these lands showed
that high level of salinity occurred during summer months in all these soils (Samikkutty,
1977). In pokkali and kaipad lands salinity decreased rapidly upto August and was maintained
till Dec- Jan. Orumundakan lands maintained high level of salinity in spite of leaching with
rain water. Soils on the mounds formed for sowing seeds attained low levels of salinity on
washing and leaching with rain water, while salts accumulated in the soils between the
mounds.
As a result of tidal influence, rice cultivation is practiced when salinity levels are low
and prawn culture is resorted to at other times. As the southwest monsoon sets in, salts
and various toxic elements get washed off and rice is cultivated after adopting suitable
water management practices.
From the above, it is found that keeping the soil under submergence as far as possible
is the best remedy for overcoming the problems in these soils. Subsurface tile drains which
can remove acidity as well as salinity can be recommended wherever possible (KAU, 1990,
Mathew et al, 2004).
(d) Cation Exchange Capacity(CEC) and Nutrients
CEC (which is a direct measure to store and retain nutrients ) of the laterite soils is very
low ranging from 2-4 cmol(+)kg-1 which goes upto 6 c mol(+)kg-1 in red loam soils(Figure
1.20). Sandy soils have a CEC value of <2. Kari, kayal and black soils exhibit higher CEC
ranging from 15-30 c mol (+) kg-1.
c m ol/kg
16
12
8
4
0
soil types
L a terite
R ed loa m
K u ttan a d
K ole
F orest
C oasta l sa n d y
P okk ali & K a ipa d
B la ck
Figure 20. CEC (c mol kg-1) of Kerala soils
$"
Land Environment
The values suggest that the nutrient retaining power of the soils should be improved by
appropriate management practices. The status of available nutrients (Table.1.29) shows
that Kerala soils are low to medium in major plant nutrients and deficient in certain essential
micronutrients like B. Toxicity of certain micronutrients like Fe and Mn is observed in these
soils.
Table.1.29. Available major nutrient status (kg ha-1) of Kerala
1. Laterite
Soil
Av. N
78-175
2. Forest
3.Red loam
384-550
154-171
4.Coastal sandy
5.Kuttanad (Acid saline)
6. Hydro. saline Pokkali& Kaipad
7. Kole
8. Black
9. Onattukara
11. Brown Hydromorphic
102-164
242-256
182 500
200
151-172
90-152
295-341
382-419
Av. P
14.6 17.8
Av. K
55.3

01.1
16.2-25.6
152- 258
18.0-28.61
52.3

12.8
9.6-14.8
56-83
6.85 - 10.9
60-208
5.88 - 57.2
24 592
11.5
144
18.5-23.2
48.6-59.3
8.2-14.5
58-78
22-34
172-194
28-48
112-128
A study on the available nutrient status of the major wet land soils of Kerala shows that
kari soils of Kuttanad are having the highest content of N (Table.1.30).Available P is high in
all wet land soils except Pattambi and Kattampally. Almost all the soils are low in available
K.
A perusal of the data on secondary nutrients (Table.1.31) reveals that the wet lands
are not deficient in Ca, Mg and S. The black soils of Chittoor, are found to be rich in CaCO3
concretions. In the Kari soils, presence of high amounts of sulphates and sulphides are
noted, the source being sea water and organic matter. Iyer (1989) observed that Kari soils
contain iron sulphide similar to marcasite and pyrrhotite which on exposure produces
sulphuric acid and ferrous sulphate.
Table.1.32 shows that among the micronutrients, iron toxicity is a problem in Kari soils.
Mn toxicity is not reported from any part of Kerala. The low Cu availability in Kari soils can
be attributed to the formation of insoluble complexes with organic matter and formation of
CuS and Cu2S. Deficiency of micronutrients is not seen in any of wet lands.
A perusal of the data on secondary nutrients (Table.1.31) reveals that the wet lands
are not deficient in Ca, Mg and S. The black soils of Chittoor, are found to be rich in CaCO3
Land Environment
$#
Table.1.30. Available major nutrient status (kg ha-1) of wet land soils of Kerala
Name of wetland
Vellayani-Tropic Fluvaquent
Karamana-Typic Tropaquent
Kari(Thakazhi) -Typic Sulphaquent
Karapadom(Nedumudi) Aeric
Tropaquept
Kayal(D Block) -Typic Hydraquent
Pokkali(Njarakkal) Sulphic Tropaquept
Kole(Anthikkad) -Typic Tropaquept
Pattambi-Aeric Kandiaqult
Chittoor-Petrocalcic Calciustert
Wynad-Typic Tropaquent
Kaipad(Pazhayangadi) Tropic
Fluvaquent
Kattampally-Tropic Fluvaquent
N
419
321
570
517
P
48
27
41
48
K
128
180
277
541
442
416
430
364
348
343
271
65
43
34
22
56
27
43
794
405
187
120
156
96
63
281
21
186
(Source: Usha and Varghese, 1997)
Table.1.31 Available secondary nutrient status (mg kg-1) of wet land soils of Kerala
Name of wetland
Karapadom(Nedumudi) -Aeric Tropaquept
Pokkali(Njarakkal) -Sulphic Tropaquept
Wayanad-Typic Tropaquent
Kaipad(Pazhayangadi) -Tropic Fluvaquent
Ca
621
648
1246
456
1219
1724
1072
707
4852
673
403
875
Mg
118
106
373
202
33
567
133
131
122
119
78
222
S
1496
591
4026
2517
1249
3260
1937
365
204
216
420
467
(Source: Usha and Varghese, 1997)
concretions. In the Kari soils, presence of high amounts of sulphates and sulphides are
noted, the source being sea water and organic matter. Iyer (1989) observed that Kari soils
contain iron sulphide similar to marcasite and pyrrhotite which on exposure produces
sulphuric acid and ferrous sulphate.
$$
Land Environment
Table.1.32 shows that among the micronutrients, iron toxicity is a problem in Kari soils.
Mn toxicity is not reported from any part of Kerala. The low Cu availability in Kari soils can
be attributed to the formation of insoluble complexes with organic matter and formation of
CuS and Cu2S. Deficiency of micronutrients is not seen in any of wet lands.
Table.1.32 Available micro nutrient status (mg kg-1) of wet land soils of Kerala
(Usha and Varghese, 1997)
Name of wetland
Karapadom(Nedumudi) -Aeric Tropaquept
Pokkali(Njarakkal) -Sulphic Tropaquept
Wayanad-Typic Tropaquent
Kaipad(Pazhayangadi) -Tropic Fluvaquent
Fe
431
238
2399
416
381
455
299
291
263
88
163
143
Mn
33
21
32
27
32
14
46
31
19
21
5
36
Zn
3.4
3.1
9.2
3.2
3.6
7.2
5.2
2.3
9.3
3.9
1.3
2.5
Cu
4.1
6.2
1.3
5.7
3.1
2.1
8.4
10.2
7.3
2.9
2.7
2.6
Microbiological characteristics
a. Microbial activity
Microbial bio mass is considered as the main bioindicator to analyze the soil health
state. A study on the microbial activity in Kerala soils (Philip 1971) reveals that it is the
highest in the forest soils because of the relatively high organic matter content in these
soils. The activity in general is high in the top soil and decreases with depth (Tables.1.33,
1.34 & 1.35).
Studies on the soils of Kuttanad showed that these soils had low nitrifying bacterial
population but ammonifying capacity was found to be high (Table.1.36).
Liming increases the microbial activity of the acid soils of Kerala (Nambiar, 1961).
Abundant growth of Blue Green Algae was noted in limed soils whereas in unlimed soils,
the predominant algal flora was the green ones. The BGA found were species of Scytonema,
Oscillatoria, Anabaena and Nostoc. The green algae noted were Chlamydomonas, Volvox,
Oedogonium, Tetraspora, Spirogyra and Sirogonium (Amma et al.,1966). Certain algal
forms like Aulosira fertilissima and Calothrix brevissima are encountered in all the rice
fields of the state (Aiyer,1965).
Land Environment
$%
Table.1.33. Bacterial population (106 g-1 of dry soil) in different locations and crops
(Philip, 1971)
Location & crop
Vellayani ( coconut garden )
Vellayani ( paddy field )
Trivandrum ( coconut garden )
Trivandrum ( paddy field )
Ponmudi ( forest , above 300 MSL)
1.
2.
3.
4.
5.
6.
0-7 cm
9.72
16.31
8.97
12.38
40.71
17.60
7-15 cm
7.91
10.32
9.26
14.86
55.66
9.64
15-30 cm
6.72
6.51
5.04
10.91
23.43
3.4
Table.1.34. Fungal population (106 g-1 of dry soil) in different locations and crops
(Philip, 1971)
Location & crop
1.
2.
3.
4.
5.
6.
0-7 cm
1.16
1.90
0.99
0.82
4.75
1.01
7-15 cm
1.14
0.98
0.86
0.76
4.11
0.63
15-30 cm
0.79
0.65
0.45
0.31
1.01
0.47
Table.1.35. Population of Actinomycetes (106 g-1 of dry soil) in different locations and
crops (Philip, 1971)
1.
2.
3.
4.
5.
6.
Location & crop
0-7 cm
6.24
5.41
5.91
4.60
9.13
3.11
7-15 cm
6.17
5.78
7.01
4.17
9.76
3.25
15-30 cm
4.87
5.45
3.41
2.19
4.30
2.06
Table.1.36. Bacterial activity in the Kari soils of Kuttanad (Pillai, 1964)
Soil
Depth
pH
Total count
Millions/g
Koithuruthu
Surface
subsurface
Surface
subsurface
Surface
subsurface
Surface
subsurface
5.4
6.7
3.6
5.6
3.7
2.7
4.2
3.9
0.58
0.52
0.44
0.23
0.39
0.11
0.27
0.22
Oorukari
Elurkalam
Kochuputhenkari
$&
Ammonifyin
g mg N/g
soil
21.53
19.46
26.17
22.54
23.38
12.46
23.94
16.1
N fixing
capacity mg
N/g sucrose
3.3
3.8
3.67
2.48
1.22
1.08
1.79
2.57
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b. Soil enzyme activity
Soil enzymes activity are sensitive indices of management induced changes in soil quality.
Pesticides are found to impose direct effects on enzyme activities due to their interaction
with microbial population. Hence assay of enzyme activity in soil is considered as an important
tool to obtain functional information on specific aspects of the bio- activity of the soil.
Table.1.37. Enzyme activity in soils of different agro ecosystems (Aparna,2000)
UA
Ph. A
Pr. A
DA
CA
RA
Kayamkulam
(wet land)
130.3-150.5
33.9-38.4
190.8-211.2
142.5-148.7
5.0-6.2
3.34-3.63
Pattambi
(wet land)
139.2-143.1
26.5-27.3
245.2-265.4
257.1-268.2
10.0-11.1
3.8-3.98
Chethackal
(rubber plantation)
338-351
102.5-107.3
356.5-365.8
472.4-490.6
38.3-43.2
3.8-4.6
Balaramapuram
(upland)
134.5-150.8
38.2-45.8
138.9-151.1
183.6-204.5
21.5-28.2
2.7-2.9
UA - Urease activity (ppm of urea hydrolysed g-1h-1 )
Ph. A - Phosphatase activity (mg of paranitrophenol released g-1h-1 ),
Pr. A - Protease activity mmols of amino N hydrolysed g-1h-1 ) ,
DA - Dehydrogenase activity (mg of TPF hydrolysed g-1day-1 ),
CA - Cellulase activity (ppm of glucose hydrolysed g-1day-1 ),
RA - Respiratory activity (mg of CO2 evolved g-1h-1 )
Studies on the activity of three enzymes viz. invertase, amylase and cellulase in the
rice soils of Kerala showed that the activity of these enzymes was higher in soils with a
high content of organic matter and clay percentage. The alluvial soils from Aluva had the
highest activity of urease and amylase whereas the black soils of Chittoor showed the
highest activity of invertase enzyme (Aiyer & Krishnaswamy,1971). Activity was higher in
the rhizosphere of paddy than in the non-rhizosphere. The populations of bacteria and fungi
(136.13 millions g-1 and 8.66.millions g-1 ) reached their maximum in the pre-flowering
stage of paddy whereas the actinomycetes population was at its maximum ( 14.27 millions
g-1) prior to harvest.
The rate of CO2 evolution was higher in the rhizosphere than in the non-rhizosphere
soils. Invertase and amylase were positively correlated with the rate of CO2 evolution from
the soil. Application of Lindane at normal rates did not exert any significant influence on the
microbial population.
D. Soil contamination
Indiscriminate use of chemical fertilizers and pesticides, for short-term gains, plunders
the soil and reduces the quality of the produce. The demand for pesticides and fertilizers,
the vital constituents of modern agriculture practices, has increased recently due to the
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$'
need to protect high yielding crops. Pesticides are more harmful as its constituents are
poisonous chemicals, the continued use of which upsets the delicate balance of the
ecosystem. The toxicity aspects of many of the widely used pesticides are not known to
the farmers who use it. The degradation rate of pesticides is also very slow after entering
into the environment. The wide spread use of pesticides and fertilizers has created a serious
threat to the general health of the society. Studies cite the indiscriminate use of pesticides
as reason for the unprecedented rise in the number of cancer patients in Kerala. Das et al
(2000) confirmed serious deterioration of the ecosystem of Kuttanad, the rice bowl of
Kerala as there were high concentrations of heavy metals and organochlorine pesticide
residues in water and sediment. High levels of bioaccumulation of these chemicals are
taking place in humans and animals living in the area. The studies also showed the presence
of virulent strains of poliovirus I and other viruses like hepatitis viruses in water.
Organochlorine pesticide residues are also found in considerable amounts in water. It was
observed that water and sediment in the Kuttanad system acted as sources for
bioaccumulation in the faunal compartments. High concentrations of residues were found
in plankton, benthos, earthworm, clam, fish, prawn, frog, cows milk and human blood from
the area.
The concentrations of cadmium, iron, manganese, nickel, lead, zinc, chromium and copper
in water in Kuttanad region, reported by Das et al (2000) indicates heavy metal pollution in
the hinterland area. All heavy metals except nickel and chromium exceeded the respective
permissible levels. Iron and manganese were also dominant. The heavy metal concentrations
were also identified in the sediments. The presence of metals, especially nonessential
metals like cadmium and lead, in edible organisms and cow milk, reported in the study
raises serious concern. These indicated that the local people are facing considerable risk of
heavy metal poisoning. The high concentration of copper at the discharge point of
Manimalayar suggests its source to the rubber plantations upstream as copper sulphate is
widely sprayed in rubber plantations.
Similarly, the analysis of water and sediment samples collected from the creek and
adjacent wetlands near Udyogamandal Industrial Estate indicated high organic contaminants
and heavy metals (Labunska et al., 1999). The study indicated the following:
%
•
Sediment from the creek near Hindustan Insecticides Limited (HIL) contained more
than 100 organic compounds, 39 of which were organochlorine, including DDT and
its metabolites, endosulfan and several isomers of hexachlorocyclohexane (HCH).
•
In contrast, sediment collected immediately upstream from HIL contained none of
these compounds at detectable levels (and no identifiable organochlorine), strongly
suggesting that discharges and/or run-off from the HIL plant have resulted in heavy
contamination of the creek sediments with a range of pesticide residues and other
hazardous organochlorine chemicals.
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•
DDT and HCH were also detectable in the water/effluent sampled downstream
from HIL and the wetlands surrounding the Udyogamandal estate. The presence of
other chlorinated chemicals were also identified in the creek (particularly chlorinated
benzophenones) suggests widespread contamination of the wetland.
1.2.5.4 Impact
In Kerala state more than 67 % of the total geographic area is subjected to soil
degradation due to different factors like erosion, landslides, water logging, acidification,
laterisation, pollution etc. Soil erosion by heavy rainfall with landslides has become a common
phenomenon in high altitude zones. The cultivated fallows on 25 % sloping lands produced
the highest run off and soil loss. When compared to the national average, the rate of loss
in Kerala is very high. Large areas of long- settled marginal lands are now under intensive
crop production as a result of high and rapidly growing rural population. Human settlements
compete for use of agricultural lands. Over exploitation for subsistence and commercial
uses has led to loss of vegetation for soil cover. Soil erosion and nutrient depletion are
common, though there is evidence that intensification has some times led to greater use of
soil protecting practices.
This type of quality deterioration had direct impacts on agricultural productivity. New,
high-yielding crop varieties often require increased inputs of nutrients and more stable
water regimes in order to produce maximum yield. Loss of soils ability to hold and store
nutrients and water has significantly restrained the achievement of the full yield potentials
of new agricultural technologies. New technologies may allow yields to increase or stay
the same, even in the face of soil degradation, but these yields may mask important losses
in the productive potential that could have been realized if soil quality had not been reduced.
The true loss of productivity because of soil mismanagement or degradation is this loss in
productive potential.
Soil degradation causes both direct and indirect degradation of water quality. Soil
degradation from erosion leads directly to water quality degradation through the delivery of
sediments and agricultural chemicals to surface water. Soil degradation indirectly causes
loss of biological activity which can increase the vulnerability of soils to erosion and
exacerbate the water quality problems associated with sedimentation.
The indirect effects of soil quality degradation may be as important as the direct damages
resulting from sediment delivery, but they are often overlooked. Soil degradation impairs
the capacity of soils to regulate water flow through watersheds. The physical structure,
texture, and condition of the soil surface determine the portion of precipitation that runs
off or infiltrates soils. In the process, the volume, energy, and timing of seasonal stream
flows and recharge to groundwater are determined. Soil erosion and compaction degrade
the capacities of watersheds to capture and store precipitation. Stream flow regimes are
Land Environment
%
altered, seasonal patterns of flow are exaggerated, increasing the frequency, severity, and
unpredictability of high-flow periods and extending the duration of low-flow periods. The
increased energy of runoff water causes stream channels to erode, adding to sediment
loads and degrading aquatic habitat for fish and other wildlife. Soil degradation that leads to
the loss of a soils capacity to buffer nutrients, pesticides, and other inputs accelerates
the degradation of surface water or groundwater quality. Erosion not only results in the
direct transport of sediment, nutrients, and pesticides to surface waters but also reduces
the nutrient storage capacity of soils. A reduced nutrient storage capacity may lead to less
efficient use of applied nutrients by crop plants and a greater potential for loss of nutrients
to surface water and groundwater.
The pesticides held by soil organic matter or clay may become more mobile in the soil
environment as erosion reduces organic matter levels and changes the soils texture .Reduced
biological activity can slow the rate at which pesticides are degraded, increasing the likelihood
that the pesticides will be transported out of the soil to surface water or groundwater. The
use of chemicals contaminates the water table and causes health hazards to those consuming
the produce. Many of the pesticides, which are used by the Govt. agencies for crops, are
turning lethal not only to human beings but also highly toxic to fish, birds, fowl, bees and
wildlife. Many of such compounds exhibit rapid degradation in water and bind to soil particles
and persist for a relatively long period. Just like Endosulfan, a toxic pesticide, most of them
do not leach into groundwater, but are particularly prone to runoff immediately after spraying.
A study conducted by Centre for Science and Environment (CSE, 2001) reported results of
its laboratory analysis on samples brought from villages of Kasargode district, Kerala,
where a lot of unusual diseases related to the central nervous system have been reported,
especially among children. The first tests conducted on the level of pesticide contamination
in the village showed that extremely high levels of the organochlorine pesticide endosulfan
were present in all the samples, from human blood and milk, to soil, water, fruits, vegetables,
cows milk and skin tissue, fish and frog.
The pesticide contamination in soil results in different abnormalities like cerebral palsy,
retardation of mental and/or physical growth, epilepsy and congenital anomalies like stag
horn limbs are very common among children. There are too many cases of cancer of the
liver and blood; infertility and undescended testis among men; miscarriages and hormonal
irregularities among women; skin disorders; and asthma, to name a few. Psychiatric problems
and suicidal tendencies have also been rising.
Two major pesticides reported in Kerala environment are Hexachlorocyclohexane (HCH)
and Endosulfan. HCH, which is introduced into the environment from industrial discharges,
insecticide applications or spills may cause significant damage. Acute toxic effects may
include the death of animals, birds, or fish, and death or low growth rate in plants (Bunton,
1996). The insecticide load in surface waters does not ordinarily reach concentrations
%
Land Environment
acutely toxic to aquatic fauna. However, lindane, a gamma-isomer of hexachlorocyclohexane,
has high chronic toxicity to aquatic life. The effects of low insecticide concentrations often
appear only after relatively long exposure times. Chronic exposure to lindane can be
hazardous to freshwater macroinvertebrates even at unexpectedly low concentrations
(Schulz et al. 1995). Such low-concentration effects may depend on both species and
substance and therefore cannot be predicted from toxicity data at higher concentrations.
Manufacture and usage of lindane continues in numerous countries, and production of
technical HCH is suspected to be continuing in some parts of the world. Li (1999) concluded
that India was probably still the most heavily contaminated country with respect to
environmental levels of technical HCH.
The pesticide endosulfan is persistent in the environment, with a half life in soil for
several years. It may accumulate in the bodies of fish and other organisms exposed to
endosulfan contaminated water. The main source of human exposure to endosulfan is via
ingestion of food that contains this pesticide as a result of direct pesticide application or
bio-concentration (ATSDR 1997). Endosulfan may be lethal to humans and animals by
inhalation, oral or dermal exposure. The main target is the central nervous system. In
studies on experimental animals, damage to the liver, kidney, gastrointestinal, haematopoietic
and dermal systems and developing foetuses have also been demonstrated following
exposure to endosulfan (ATSDR 1997). Endosulfan has also been found to exhibit some
oestrogenic properties in freshwater invertebrates (Zou and Fingerman 1997).
The wastes, which are not scientifically treated, get decayed and create great
environmental problems in Kerala as well. These are storehouses of different types of
microbes and other pathogens causing different health problems to the public as a whole
and the nearby residents in particular. These waste dumping areas are becoming shelters
of flies, mosquitoes, rats and other rodents, which are the spreaders to diseases like
Tetanus, Yellow fever, Dengue, Plague and very recently Chikungunya out break in Kerala.
Compaction in combination with other soil degradation processes can reduce the health
of crop root systems, leading to less efficient nutrient use and increasing the pool of
residual nutrients that can be lost to surface water or groundwater. The decline in crop
productivity and farm profitability associated with this gradual deterioration in soil health
and quality, is a downward spiral that cannot be remedied by increasing farm inputs. To
enhance soil quality, everyone must recognize that the soil resource affects the health,
functioning, and total productivity of all ecosystems. We must become more aware of
potential side effects of soil management and land-use decisions.
1.2.4.5 Response
Properly managed, organic farming reduces or eliminates soil and water pollution and
helps conserve water and soil on agricultural lands. Organic farming is one of several
Land Environment
%!
approaches to sustainable agriculture. In order to overcome the pollution threat from
excessive fertilizer application, Government of Kerala has decided to encourage organic
farming. The State is planning to extend support in line with the National Programme on
Organic Farming. It is evolved based on the guidelines of the International Federation of
Organic Agricultural Movement (FOAM), the Codex Alimentarius Commission (Codex), a
joint organisation of FAO and WHO, and European Union Standards. There are many nongovernmental organizations in the state who have already taken initiatives for popularizing
organic farming for sustainable agriculture.
A study by the National Institute of Occupational Health (NIOH) and an enquiry by a
committee constituted by Government of Kerala, in the background of unusually high
incidence of deformities and diseases in Padre, a village in Keralas Kasaragod district, and
its linkage with excessive use of endosulfan, an organochlorine pesticide, established the
extremely high adverse impact of excessive use of chemical pesticides. Subsequently,
both the Union and State governments banned aerial spraying of endosulfan. Owing to
public pressure and the weight of evidence, the Government of Kerala suspended all uses
of endosulfan pesticide. This conveyed the dangers of using excessive chemical pesticides
in farms.
In order to prevent the possibility of soil contamination due to the disposal of industrial
wastes, the Government of India made it mandatory for all those generates industrial
wastes to have environmental management plan for its recovery, reuse, recycle or safe
disposal. The Central Pollution Control Boards stipulates these conditions from time to
time and the State Pollution Control Boards monitor the satisfactory compliance. In addition,
the Government of India promulgated the Hazardous Wastes (Management and Handling)
Rules, 1999 under the Environmental Protection Act, 1986. The rule necessitated an
occupier and operator of a hazardous waste management facility to take responsibility for
the proper collection, reception, treatment, storage and disposal of hazardous waste. The
rule stipulates the details as to how the hazardous wastes has to be handled, transported
and disposed.
The management and handling of municipal solid waste is made the responsibility of
civic bodies. The Kerala Panchayati Raj Act, 1994 and the Kerala Municipalities Act, 1994
includes various provisions with regard to various measures to be adopted for domestic
waste collection and management. The Government of India brought out a comprehensive
rule, namely, the Municipal Solid Waste (Management and Handling) Rules, 2000 which
stipulates detailed guidelines and conditions for collection, transportation, processing/
treatment and disposal of biodegradable and non-biodegradable wastes. Accordingly,
Government of Kerala launched intensive initiatives, including the setting up of Clean Kerala
Mission. This is with a long-term vision for a waste free, unpolluted, hygienic and clean
Kerala by evolving a new healthy citizenship believing in zero waste concept, that of
reduction, reuse, recycle and recover at least 80% of the waste generated and a society
%"
Land Environment
inclined to create wealth from waste. Accordingly, all the Urban Local Bodies were persuaded
to prepare integrated solid waste management projects with the support of the mission.
Most of the local bodies either implemented or implementing waste management projects.
In addition, the Government of Kerala has launched a major campaign for waste free Kerala
focusing on the Grama Panchayats for popularizing the management of waste by the
producers themselves, as far as possible in the household. These campaigns are yielding
result, but the progress is slow.
1.3. Conclusions and Recommendations
Population pressure and urbanization have disturbed the desirable landuse system of
the State. The indiscriminate reclamation of wetlands, especially paddy land, and their
conversion for non-agricultural purposes, reduced the food crop production and degraded
the ecosystem balance. In order to overcome the deteriorating scenario, agricultural
intervention has to be planned considering the resource potential, its sustainability and
environmental aspects, especially the aspects of land capability and suitability. The guidelines
of Food and Agricultural Organization (FAO) on land suitably enable appropriate landuse
planning especially in the agricultural sector. The crop suitability model for a micro watershed
prepared through participatory and integrated land evaluation for a selected watershed in
Thiruvananthapuram district is worth considering for replication (Samad, 2004).
The sustainable management of landuse looks to be a distant dream, considering the
intensive intervention. The land is mostly subjected to undesirable practices and hence
subjected to serious degradation. In order to over come this and to have a comprehensive
action plan for conservation and management of limited land that the State has, it is
appropriate to evolve a detailed Land Use Policy and integrated action plan. The policy
should be followed up with necessary statutory regulations and appropriate institutional
mechanisms, with effective provisions to prevent further degradation of land and upgrade
the existing status of land environment.
Most of the existing mineral based industries today are confined to the extraction and
sale of raw minerals without optimal value addition. This is a drain in economy. Therefore,
it is high time to concentrate on indigenous beneficiation of minerals to develop high quality
end products. The lack of sufficient attention in this field also denied the scope for reasonable
employment opportunities and desired economic development.
Management practices for reducing soil erosion include agronomic and engineering
measures. Agronomic measures are comparatively less expensive. Minimum tillage, zero
tillage, conservative tillage, mulching, cover cropping, multi tier cropping, contour ploughing,
optimal fertilizing and organic farming are some of the important agronomic practices.
Engineering measures are contour bunding, bench terracing, land leveling, gully plugging,
check dams, and such other water harvesting structures etc.
Land Environment
%#
It is essential to emphasize watershed based approaches for conservation and
management of the natural resources in a systematic manner. It provides a ridge to valley
approach, thereby protecting the upper reaches from soil erosion and conservation of water
depending on the potential of each parcel of land. There is also a necessity of popularizing
appropriate technology applications in watershed management programmes.
To protect soils from unsustainable landuse practices and pollution, a soil protection
strategy should be developed and implemented. Such a strategy should include the
maintenance of a sustainable environment, precautionary measures for soil protection,
protection of multifunctional role of soils, framework for a soil monitoring programme etc.
Knowledge relating to the sustainable use of soil is scarce. There are many areas where
information is required, particularly regarding the input, persistence and bioavailability of
potential contaminants as well as their impacts on soil quality and sustainability. Information
is also required on their effects on key soil processes such as nutrient cycling and
decomposition of organic matter. To assess the long-term sustainability of agriculture, it is
crucial that accurate information on the soil resource, such as levels of organic matter,
nutrient status and pH, is collected at regular intervals. Long-term effects of fertilizer and
pesticide use on soil quality need to be assessed. There is a need for a systematic
examination of soil erosion along with the quantification of erosion rates. The role of land
management in the maintenance of soil quality and alleviation of many environmental
problems needs to be assessed. Such management will have an important role to play in
minimizing physical damage and loss of soil, minimizing the impacts of soil acidification and
eutrophication, conserving current carbon stocks and minimizing future emissions of
greenhouse gases from soils.
Inputs of organic wastes to soils are largely unregulated and impacts on soil quality and
sustainability are unknown. Information needs to be gathered on the inputs and accumulation
of the potential contaminants present in organic wastes, such as heavy metals, organic
compounds and pathogens, and impacts on soil quality.
Preventive and curative measures against pollution and contamination of soil and land
may receive high priority for years to come, and technological measures to prevent the ill
effects on human health will get priority in short term. Recent trends in agriculture technology
clearly indicate a major change in the traditional agricultural practices. Often it is touted
that in order to cater to the large and increasing demand for agricultural produce, one has
to use fertilizers, pesticides and use tillage to remove weeds etc. However, recent reports
by the Food and Agricultural Organization (FAO) clearly show that conservation agricultural
practices can be employed to have sustainable farming. These techniques, currently employed
in Brazil, many parts of Western Europe and the U.S. clearly show that farming can be
practiced without sacrificing yield. Hence, the following points are to be recommended for
ensuring food security without upsetting the natural ecological balance.
%$
Land Environment
•
Waste disposal mechanisms of major pesticide companies must be checked
regularly.
•
Strict rules must be introduced to restrict the extent of use of pesticides in
agriculture in our State.
•
A system should also be in place to ensure the safety of products brought from
neighboring States.
•
Government must launch programmes to promote use of organic fertilizers and
encourage organic farming among farmers.
•
Experts in the field should be consulted on a timely basis and interventions in
policies should be modeled on that.
•
Public should be made aware of the advantages of using organic food products.
•
techniques enabling contamination-free produce
•
mechanisms ensuring adherence to these techniques
•
reporting/rectifying violations if any and checks to confirm and certify output for
quality.
•
The methods of organic farming should be strengthened using vigorous research
and traditional knowledge in pest management using tobacco, gourd and sugarcane
should be used
•
The Agriculture Department and The Agricultural Universities have to come out
with a comprehensive plan.
•
The core issue is in reaching a balance in production and fair return to farmers.
Hence standards should be set regarding the use of chemical fertilizers and
pesticides.
•
Long term soil conservation, lesser threat to bio and eco diversity from chemical
fertilizers, reduced pollution of water table by chemical residues and better soil
nutrition
•
In Kerala, NGOs should work with agriculture scientists and irrigation engineers to
re-educate farmers in different aspects of farming, fertilizer application etc.
Because of a lack of information relating to changes in soil properties over time, it is not
possible, at this stage, to assess whether current land use practices and pollutant inputs
are sustainable. For these reasons, a quantitative assessment of the soil resource is required
as an initial step in the implementation of a soil monitoring programme. Long term monitoring
Land Environment
%%
of soil quality is essential in order to assess whether the current status is sustainable and
to assess whether potential soil protection measures are successful.
Many pressures from human activities can affect the physical, biological and chemical
components of soil leading to changes in soil quality. But no serious concern has been given
to potential threats of soil quality deterioration. This is partly due to the long time scales
over which soils respond to these pressures and to difficulties associated with regulating
a resource, which is primarily in private ownership. In addition, there is no universally
accepted definition of soil quality and no numerical standards, with which to compare the
qualities of different soils in relation to their function, or to monitor changes over time.
Because of the very high population density, all forms of biotic pressure on soil are high and
hence, it is an immediate and critical necessity to map and monitor soil quality and promptly
take remedial measures.
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&"
Land Environment
WETLANDS OF KERALA
Wetlands are kidneys of our landscape
We are cutting out our kidneys to enlarge our stomachs
Eric Freyfogle, Illinois law professor
2.1.
INTRODUCTION
2.1.1. Background
Wetlands are ecotones or transitional zones that occupy an intermediate position
between dry land and open water. Wetland ecosystems are dominated by the influence
of water, they possess characteristics of both terrestrial and aquatic ecosystems and
properties that are uniquely of their own. Wetlands support a wide array of flora and
fauna and deliver many ecological, climatic and societal functions. Scientists often
refer to wetlands as the kidneys of the earth and forests as the lungs of the earth.
India by virtue of its extensive geographical stretch and varied terrain and climate,
supports a rich diversity of inland and coastal wetlands.
Kerala is well known for its wetlands. These wetlands provided livelihood to the
residents in the area in the forms of agricultural produce, fish, fuel, fiber, fodder, and
a host of other day-to-day necessities. As long as human intervention remained minimal,
the ecosystem, through its all-encompassing balancing nature, was self-cleansing.
But the development demands that determine the choice of the paths upset the natural
harmony. Infrastructure development in the form of roads, railways, and other lines of
communication fragmented the contiguity of the wetlands, and destroyed extensive
tracts of coastal vegetation thereby upsetting the entire complex ecology; rapid
Wetlands of Kerala
&#
urbanisation encroached into the rich and luxuriant mangrove forests, while industrial
development not only caused pollution but prevented any regeneration possibilities as
well; modern shrimp farms brought in the final onslaught - the irreversible destruction
of wetlands. Coastal Kerala with its high density of population cannot bear such
onslaughts any longer. The degradation of the wetlands of Kerala is not an isolated
event. Worldwide, wetlands are in peril. They are either being polluted, drained or
filled up to give way for development. The rate of wetland loss has accelerated in
recent years. Thus the wetlands are now the most threatened ecosystems of our
planet.
This report is the result of a multidisciplinary study and analysis of the status of the
wetlands of Kerala mainly based on the earlier studies and is presented in four sections.
The section I gives an introduction to the wetlands with background, concept and
definition, origin and classification, status of wetlands in India and Kerala, biodiversity,
previous studies and institutional and legislative mechanisms. Section II describes the
issues in conservation and sustainable management frame work for reporting of the
wetlands of Kerala, using the DPSIR (Driving forces of environmental change, Pressures
on the environment, State of the environment, Impacts on population, economy,
ecosystems and Response of the society) framework. The status of five wetlands,
three Ramsar sites, one national site and one manmade reservoir in the State is
critically anlysed using the DPSIR framework, in the section III. The conclusions and
recommendations of the study are given in section IV.
2.1.2 Definition of Wetlands
The Ramsar Convention (1971) defines wetlands as:
areas of marsh, fen, peat land or water, whether natural or artificial,
permanent or temporary, with water that is static or flowing, fresh, brackish
or salty including areas of marine water, the depth of which at low tide
does not exceed 6 meters. It may also incorporate riparian and coastal
zones adjacent to the wetlands and islands or bodies of marine water
deeper than 6 meters at low tide lying within the wetlands.
Cowardin et al (1979) define wetlands as the lands transitional between terrestrial
and aquatic systems where the water table is usually at or near the surface, or the
land is covered by shallow water. This includes three attributes that help to delineate
a wetland: (i) the area must be permanently or periodically inundated or water must
be present for at least seven successive days during the growing season, (ii) the area
must support hydrophytic vegetation and (iii) the substrate is predominantly hydric
soils that are saturated or flooded for a sufficiently long period to become anaerobic in
their upper layers. From the utilitarian point, wetlands can be defined as transitional
areas between permanently flooded deepwater environm ents and well drained uplands
&$
Wetlands of Kerala
that contribute a wide array of
biological, social and economic
benefits (Watzin and Gozzelink,
1992).
2.1.3 Significance of
Wetlands
Wetland systems directly
and indirectly support lakhs of
people, providing goods and
services to them. They help
check floods, prevent coastal
erosion and mitigate the effects
of natural disasters like
cyclones and tidal waves. They
store water for long periods.
Their capacity during heavy
rainfall to retain excess
floodwater
that
would
otherwise cause flooding
results in maintaining a
constant
flow
regime
downstream, preserving water
quality and increasing biological
productivity for both aquatic life
as well as human communities
of the region. Inundated
wetlands are very effective in
storing rainwater and are the
primary source for recharging
ground water aquifers.
The importance of wetlands
was clearly demonstrated by
2004 Indian Ocean Tsunami.
Wetlands may have provided a
green barrier to protect coastli
nes and the coastal comm
unities that live there. There
were localized and anecdotal
Wetlands of Kerala
Box 2.1: Warblers and wetlands
(Editorial by the The Hindu -19-03-2007)
The rediscovery in Thailand of a bird believed to be
extinct, the large-billed reed warbler, far away from
the Sutlej Valley of Himachal Pradesh where it was
first found 139 years ago, illustrates the incomplete
nature of biodiversity knowledge. Almost a year ago,
ornithologist Philip Round of Mahidol University
recorded a single individual of the small wetland
bird species in the Laem Phak Bia Environmental
Research and Development Project area in Thailand.
He published his exciting discovery recently after
Staffan Bensch of Swedens Lund University
confirmed the birds identity through DNA analysis.
This warbler is genetically distinct from two similar
birds, including the familiar Blyths reed warbler.
The rediscovery will set off a race among bird
watchers and experts to find the group of largebilled reed warblers of which the Thai specimen is a
part. Its range, believed to be somewhere between
Thailand and Northwest India, presents an
opportunity for Indian ornithologists to collaborate
with those abroad and come up with critical data
about the bird. Much work needs to be done on its
distribution, preferred habitat vegetation, and
behaviour. Moreover, the rediscovery of a long-lost
bird during a routine study is a pointer to the need
for more work in field biology in India. Only last
year, nature lovers were elated when painstaking
research by a professional astronomer, Ramana
Athreya led to the confirmed recording in Arunachal
Pradesh of a new babbler species, the Bugun
liocichla.
The rediscovery of the warbler underscores the
importance of wetlands as a biodiverse habitat.
According to a comprehensive study by the Salim
Ali Centre for Ornithology and Natural History, India
lost about 38 per cent of its wetlands during the
1990s. In some districts, the loss is as high as 88
per cent. Wetlands, apart from providing many
resources to local communities, act as flood buffers
and afford water security. This newspaper has
repeatedly editorialised on the need for greater
recognition of the role of wetlands and stronger
legislative protection. The current revenue
classification of many wetlands as wasteland
betrays poor understanding of their importance and
encourages their use as garbage dumps. Continuous
monitoring of wetlands for spatial transformations
and changes in water, vegetation, and biodiversity
is essential for their long-term viability. Birds are a
key marker of wetland health and this habitat is
crucial for the survival of many migratory species
that come as winter visitors to the sub-continent.
&%
reports from around the Indian Ocean region of how the dam aging impact of the
Tsunami was reduced behind mangrove stands and coral reefs.
Many wading birds and waterfowl like egrets, herons and cranes nest in wetlands.
Of the 78 endangered species of birds in India, 55 depend on wetlands (37 threatened
species such as the Sarus crane and the spot-billed pelican and 18 near threatened
species led by the lesser flamingo and the white ibis). Wetlands also provide food and
shelter for mammals. They act as natural filters and help remove a wide range of
pollutants from water, including harmful viruses from sewage and heavy metals from
industries. Wetlands retain nutrients by storing eutrophic parameters like nitrogen and
phosphorus and accumulating them in the sub-soil, thereby decreasing the potential
for eutrophication.
Mangrove forests are valued for production of fish and shell-fish, live-stock fodder,
fuel and building materials, local medicine, honey and bees-wax and for extracting
chemicals used in tanning leather. Apart from that, they provide durable timber, fuel
wood, and protein rich fodder for cattle, edible fruits, vegetables and traditional
medicines.
The importance and usefulness of wetlands was first brought to the notice of the
world through a Convention on Wetlands held at the Iranian city of Ramsar, in the
year 1971. The Convention was an inter-governmental treaty that provided the
framework for national action and international co-operation for the conservation and
wise use of wetlands and their resources. As of 9th March 2007 there are 154
Contracting Parties to the Convention, with 1650 wetland sites, totaling 149.6 million
hectares, designated for inclusion in the Ramsar list of Wetlands of International
Importance.
2.1.4 Origin and Classification of Wetlands
Formation of wetland is a function of climate (precipitation, temperature, wind and
insolation), hydrology (internal and external drainage), chemistry (water and soils),
geomorphology (landform and soil parent material), and biology (fauna and flora).
Wetland development is dynamic as different types of wetlands represent transitions
from one type to another. As a result, wetlands often share characteristics of more
than one wetland class, form, subform or type.
Three major factors characterise a wetland: water, substrate (physico-chemical
features) and biota. Of the three factors that characterise wetlands, water has special
status because neither the characteristic substrates nor the characteristic biota of
wetlands can develop in the absence of specific hydrologic conditions. Disturbance of
the biota or substrate can produce a wetland in which the characteristic substrates or
organisms are absent at least temporarily. In contrast, elimination of the characteristic
hydrology of a wetland eliminates the wetland, even though the characteristic substrate
and organisms can persist for sometime after the hydrologic change. Thus, when
hydrology has been altered, the presence of organisms and substrate that are
characteristic of wetlands is not necessarily indicative of wetlands.
&&
Wetlands of Kerala
The Ramsar Bureau has coined a Ramsar Classification System for Wetland Type
as approved by Recommendation 4.7 and amended by Resolution VI.5 of the Conference
of the Contracting Parties (COP). The categories listed herein are intended to provide
only a very broad framework to aid rapid identification of the main wetland habitats
represented at each site.
I. Marine/Coastal
A
-
Permanent shallow marine waters less than six meters deep at low tide;
include sea bays and straits.
B
-
Marine sub tidal aquatic beds; includes kelp beds, sea-grass beds, and
tropical marine meadows.
C
-
Coral reefs.
D
-
Rocky marine shores; includes rocky offshore islands, sea cliffs.
E
-
Sand, shingle or pebble shores; includes sand bars, spits and sandy
islets; includes dune systems.
F
-
Estuarine waters; permanent water of estuaries and estuarine systems
of deltas.
G
-
Intertidal mud, sand or salt flats.
H
-
Intertidal marshes; includes salt marshes, salt meadows, salting, raised
salt marshes; includes tidal brackish and freshwater marshes.
I
-
Intertidal forested wetlands; includes mangrove swamps, nipa swamps
and tidal freshwater swamp forests.
J
-
Coastal brackish/saline lagoons; brackish to saline lagoons with at least
one relatively narrow connection to the sea.
K
-
Coastal freshwater lagoons; includes freshwater delta lagoons.
Zk(a) -
II.
Karst and other subterranean hydrological systems, marine/coastal
Inland Wetlands
L
-
Permanent inland deltas.
M
-
Permanent rivers/streams/creeks; includes waterfalls.
N
-
Seasonal/intermittent/irregular rivers/streams/creeks.
O
-
Permanent freshwater lakes (over 8 ha); includes large oxbow lakes.
P
-
Seasonal/intermittent freshwater lakes (over 8 ha); includes floodplain
lakes.
Q
-
Permanent saline/brackish/alkaline lakes.
R
-
Seasonal/intermittent saline/brackish/alkaline lakes and flats.
Wetlands of Kerala
&'
Sp
-
Permanent saline/brackish/alkaline marshes/pools.
Ss
-
Seasonal/intermittent saline/brackish/alkaline marshes/pools.
Tp
-
Permanent freshwater marshes/pools; ponds (below 8 ha), marshes and
swamps on inorganic soils; with emergent vegetation water-logged for
at least most of the growing season.
Ts
-
Seasonal/intermittent freshwater marshes/pools on inorganic soil; includes
sloughs, potholes, seasonally flooded meadows, sedge marshes.
U
-
Non-forested peat lands; includes shrub or open bogs, swamps, fens.
Va
-
Alpine wetlands; includes alpine meadows, temporary waters from
snowmelt.
Vt
-
Tundra wetlands; includes tundra pools, temporary waters from
snowmelt.
W
-
Shrub-dominated wetlands; Shrub swamps, shrub-dominated freshwater
marsh, shrub Carr, alder thicket; on inorganic soils.
Xf
-
Freshwater, tree-dominated wetlands; includes freshwater swamp forest,
seasonally flooded forest, wooded swamps; on inorganic soils.
Xp
-
Forested peat lands; peat swamp forest.
Y
-
Freshwater springs; oases.
Zg
-
Geothermal wetlands
Zk(b) -
Karst and other subterranean hydrological systems; inland
Note: floodplain is a broad term used to refer to one or more wetland types,
which may include examples from the R, Ss, Ts, W, Xf, Xp, or other wetland types.
Some examples of floodplain wetlands are seasonally inundated grassland (including
natural wet meadows), shrub lands, woodlands and forest. Floodplain wetlands are
not listed as a specific wetland type herein.
III.
'
Man-made wetlands
1
-
Aquaculture ponds (e.g., fish/shrimp)
2
-
Ponds; includes farm ponds, stock ponds, small tanks; (generally below
8 ha).
3
-
Irrigated land; includes irrigation channels and rice fields.
4
-
Seasonally flooded agricultural land.
5
-
Salt exploitation sites; salt pans, salines, etc.
Wetlands of Kerala
6
-
Water storage areas; reservoirs/barrages/dams/impoundments (generally
over 8 ha).
7
-
Excavations; gravel/brick/clay pits; borrow pits, mining pools.
8
-
Wastewater treatment areas; sewage farms, settling ponds, oxidation
basins, etc.
9
-
Canals and drainage channels, ditches.
Zk(c)-
Karst and other subterranean hydrological systems; human-made
According to Ministry of Environment & Forests, Government of India, wetlands
are broadly divided into Inland wetlands and Coastal wetlands and each class is further
divided into different types.
Geomorphologically, the wetlands in Kerala may be divided among five major systems
at the broadest level as marine, estuarine, riverine, and lacustrine and palustrine. Due
to the unique physical characteristics Kerala endows, like backwater systems and a
diverse terrain of high land, midland and low land within a thin strip of landmass of
about 38864 sq km, there exists much ambiguity in the classification of wetlands.
Thus, major classes and types of wetlands are redefined keeping the MoEF classification
system as the standard. Accordingly the following major wetland classification system
is suggested by the detailed study on wetlands of Kerala by CED (2003a), and is given
in table 2.1.
Table 2.1: Classification Scheme for Wetlands of Kerala (CED, 2003a)
Wetland classes
Inland Wetland
Wetland types
Fresh water lakes
Fresh water swamps
Reservoirs
Large Ponds
Coastal Wetlands
Estuaries/ Backwaters
Mangrove Forests
Kol, Kuttanad and Pokkali wetland Systems
Coastal Swamps
Mud flat
Aquaculture Pond
Islets/Thuruthu
Wetlands of Kerala
'
Delineation of wetlands into the above said categories is mainly done on the basis
of various parameters like location, physical extent, depth, salinity, bio-diversity etc.
2.1.5.
Status of Wetlands in India
The Ministry of Environment and Forests, Government of India (1990) estimated
that different types of wetlands occupies 4.7 million ha, of which 1.5 million ha are
natural, 2.6 million are man made and 0.6 million ha are Mangrove vegetation. The
results of the nation wide wetland inventory (Garg et al., 1998) reveals that there are
27,403 wetland units in the country occupying 7.6 million ha, of which coastal Wetlands
are 3959 units with 4.0 million ha, whereas inland wetlands are 23,444 units with
3.6 million ha. So far, India has designated 25 wetland sites as Ramsar sites of
International Importance (table 2.2).
Table 2.2: Wetlands in India designated as Ramsar Sites (WI, 2007)
No.
'
Name
State
Date of
Declaration
1.
Ashtamudi Backwater
Kerala
19/08/02
2.
Bhitarkanika Mangroves
Orissa
19/08/02
3.
Bhoj Wetland
Madhya Pradesh
19/08/02
4.
Chilka Lake
Orissa
01/10/81
5.
Deepor Beel
Assam
19/08/02
6.
East Calcutta Wetlands
West Bengal
19/08/02
7.
Harike Lake
Punjab
23/03/90
8.
Kanjli
Punjab
22/01/02
9.
Keoladeo National Park MR
Rajasthan
01/10/81
10.
Kolleru Lake
Andhra Pradesh
19/08/02
11.
Loktak lake MR
Manipur
23/03/90
12.
Point Calimere Wildlife and Bird Sanctuary
Tamil Nadu
19/08/02
13.
Pong Dam Lake
Himachal Pradesh
19/08/02
14.
Ropar
Punjab
22/01/02
15.
Sambhar Lake
Rajasthan
23/03/90
16.
Sasthamkotta Lake
Kerala
19/08/02
17.
Tsomoriri
Jammu & Kashmir
19/08/02
18.
Vembanad-Kol Backwater system
Kerala
19/08/02
19.
Wular Lake
Jammu & Kashmir
23/03/90
Wetlands of Kerala
20.
Upper Ganga*
Uttar Pradesh
08/11/05
21.
Surinsar-Mansar*
Jammu & Kashmir
08/11/05
22.
Hokera (Hokersar)*
Jammu & Kashmir
08/11/05
23.
Rudrasagar*
Tripura
08/11/05
24.
Renuka*
Himachal Pradesh
08/11/05
25.
Chandertal*
Himachal Pradesh
08/11/05
MR- sites under Montreaux Record.
•
Wetlands identified as Ramsar sites during the CoP 09 meeting held at Uganda
during 8-15 November, 2005.
The total area covered under the 25 sites is 6, 77,131 ha. These 25 wetland sites
represent different habitats. Of these three Ramsar sites are in Kerala - Vembanad
backwater and Kole lands, Ashtamudi backwater and Sasthamkotta fresh water Lake.
2.1.6 Wetlands of Kerala : Present Scenario
In Kerala, despite its small land area of 38864 km2 has about 590 km long coastline
studded with worlds best string of beaches. It is bestowed with a vast network of
backwaters, lagoons, natural lakes, rivers and canals.
The State has two clearly distinct rainfall seasons i.e., south west monsoon and
north east monsoon resulting in near water-logged conditions in almost 20% of the
total geographic area of the State. Thus, as much as one fifth of its total landmass is
wetlands. Nair et al (2001) reported a total of 217 wetland areas in Kerala (table 2.3),
of which157 greater than 56.25 ha with an aerial extend of 127930 ha, in which 64
designated as inland wetlands (area 34199.5 ha), whereas 93 are coastal wetlands
(area 93730.5 ha).
Table 2.3: Area under wetlands of Kerala (Nair et al, 2001)
Wetlands
Area(ha)
%Area
No. of units
Natural
2180.00
1.70
11
Man-made
32019.57
25.03
53
Total
34199.57
26.73
64
Natural
85671.50
66.97
86
Man- made
8059.00
06.30
07
Total
93730.50
73.27
93
Grand Total
127930.07
100
157
Inland wetlands
Coastal Wetlands
Wetlands of Kerala
'!
Fig.2.1: Location Map of selected wetlands of Kerala (CED, 2003a)
'"
Wetlands of Kerala
There are 32 major backwaters/estuaries in Kerala (table 2.4)
Table 2.4: Backwaters/ Estuaries of Kerala (CED, 2003a)
No Name
District
1.
Karingote estuary
Kasaragode
2.
Nileswar backwater
Kasaragode
3.
Kava backwater
Kannur
4.
Dharmapatanam backwater
Kannur
5.
Mannayed estuary
Kannur
6.
Mahe estuary
Kannur
7.
Kattampally
Kannur
8.
Kotta backwater
Kozhikode
9.
Korapuzha estuary
Kozhikode
10. Payyoli backwater
Kozhikode
11. Elathur backwater
Kozhikode
12. Kallayi backwater
Kozhikode
13. Beypore estuary
Kozhikode
14. Kadalundi estuary
Kozhikode/Malappuram
15. Conolly Canal
Kozhikode
16. Puraparamba backwater
Malappuram
17. Purathur / Ponnani estuary
Malappuram
18. Chettuva backwater
Thrissur
19. Azheekode estuary
Thrissur
20. Kodungalloor backwater
Thrissur
21. Akathumuri lake
Thrissur
22. Cochin estuary
Ernakulam
23. Vembanad backwater
Kottayam & Alappuzha
24. Kayamkulam backwater
Alappuzha
25. Ashtamudi estuary
Kollam
26. Paravoor backwater
Kollam
27. Edava Nadayara backwater
Thiruvananthapuram
28. Anchuthengu backwater
Thiruvananthapuram
29. Kadinamkulam backwater
Thiruvananthapuram
30. Veli lake
Thiruvananthapuram
31. Poonthura backwater
Thiruvananthapuram
32. Poovar backwater
Thiruvananthapuram
Wetlands of Kerala
'#
Compared to coastal land, the highland and midland hold very few wetlands. There
are 7 major freshwater lakes in Kerala, which have no direct connection with the
Arabian Sea (table 2.5).
Table 2.5: Freshwater Lakes of Kerala (CED, 2003a)
No.
Name
District
1.
Pookode
Wayanad
2.
Muriyad
Thrissur
3.
Kattakambal
Thrissur
4.
Enammakkal
Thrissur
5.
Manakkodi
Idukki
6.
Sasthamkotta
Kollam
7.
Vellayani
Thiruvananthapuram
Manmade lakes and reservoirs created by constructing dams across various rivers
in the Western Ghats contribute to a sizeable proportion of artificial wetlands of the
State (table2.6).
Table 2.6: Reservoirs of Kerala
(Compiled from various sources, mainly from KSEB website, www.kseboard.com)
'$
No
Reservoir
River Basin
District
Area (ha) - @
FRL
1.
Pazhassi
Valapattanam
Kannur
648
2.
Kuttiyadi
Kuttiyadi
Kozhikode
1052
3.
Malampuzha
Bharathapuzha
Palakkad
2313
4.
Mangalam
Bharathapuzha
Palakkad
393
5.
Meenkara
Bharathapuzha
Palakkad
259
6.
Chulliyar
Bharathapuzha
Palakkad
159
7.
Pothundi
Bharathapuzha
Palakkad
363
8.
Walayar
Bharathapuzha
Palakkad
259
2092
9.
Parambikulam
Bharathapuzha
Palakkad
10.
Thunakadavu
Bharathapuzha
Palakkad
283
11.
Kanjirapuzha
Bharathapuzha
Palakkad
512
12.
Peechi
Karuvannur
Thrissur
1263
1010
13.
Chimmony
Karuvannur
Thrissur
14.
Vazhani
Kecheri
Thrissur
255
15.
Sholayar
Chalakkudi
Thrissur
870
16.
Peringalkuthu
Chalakkudi
Thrissur
263
17.
Pamba
Pamba
Idukki
570
Wetlands of Kerala
18.
Kakki
Pamba
Idukki
1800
19.
Anathodu
Pamba
Idukki
1700
20.
Gavi
Pamba
Idukki
1000
21.
Idukki
Periyar
Idukki
6160
22.
Anayirankal
Periyar
Idukki
433
23.
Kundala
Periyar
Idukki
230
24.
Mattupetti
Periyar
Idukki
324
25.
Sengulam
Periyar
Idukki
33
26.
Periyar lake
Periyar
Idukki
2890
27.
Cheruthoni
Periyar
Idukki
1700
28.
Azhutha
Periyar
Idukki
Not available
29.
Ponmudi
Periyar
Idukki
260
30.
Kallarkutyy
Periyar
Idukki
648
31.
Neriyamangalam
Periyar
Ernakulam
413
32.
Bhoothathankettu
Periyar
Ernakulam
608
33.
Idamalayar
Periyar
Ernakulam
2830
34.
Malankara
Muvattupuzha
Ernakulam
566
35.
Kallada
Kallada
Kollam
2590
36.
Neyyar
Neyyar
Thiruvananthapuram
1500
37.
Aruvikkara
Karamana
Thiruvananthapuram
258
38.
Peppara
Vamanapuram
Thiruvananthapuram
582
39
Lower Meenmutty
Vamanapuram
Thiruvananthapuram
Not available
There are many other water resources such as ponds and tanks which is one of the
specialties in Kerala. Each Panchayat/Urban local body has number of both public and
private ponds and tanks, the details of which is given in table 2.7.
Table 2.7: Ponds, tanks and other small wetlands of Kerala
(Pan Fish book, 2002)
Number of Ponds
District
No.
Panchay
at
Ponds
Private
ponds
Public
Ponds
Quarry
ponds
Irrigation
tanks
Holy
ponds
and
streams
1
Thiruvananthapuram
1633
171
00
06
34
69
2
Kollam
581
825
503
82
17
188
3
Pathanamthitta
390
456
654
138
06
59
4
Alappuzha
340
11400
00
04
03
303
5
Kottayam
226
1641
491
84
75
208
6
Idukki
66
558
77
19
47
23
Wetlands of Kerala
'%
7
Ernakulam
732
3450
296
164
72
204
8
Thrissur
984
5861
182
43
213
258
9
Palakkad
633
3070
242
134
61
314
10
Malappuram
555
3632
245
145
45
272
11
Wayanad
29
1489
01
16
61
03
12
Kozhikode
94
855
110
33
24
284
13
Kannur
292
626
470
25
35
301
14
Kasaragode
265
1858
86
11
145
148
6820
35892
3357
904
838
2634
TOTAL
By virtue of its unique location Kerala provides a wide variety of aquatic habitats,
harbouring unique types of vegetation of their own. The most important among them
are the Mangrove ecosystems which are very rich in species diversity. The important
mangrove sites of Kerala are shown in table 2.8.
Table 2.8: Mangrove Ecosystems, Kerala (CED, 2003a)
'&
No.
Mangrove Area
District
1.
Chittari
Kasaragode
2.
Dharmadom
Kannur
3.
Nadakkavu
Kannur
4.
Edakkad
Kannur
5.
Valapattanam
Kannur
6.
Pappinisseri
Kannur
7.
Muzhapilangad
Kannur
8.
Kunhimangalam
Kannur
9.
Pazhayangadi
Kannur
10.
Kavvai
Kannur
11.
Thalassery
Kannur
12.
Ezhimala
Kannur
13.
Mahe
Kannur
14.
Kotti
Kozhikode
15.
Koduvalli
Kozhikode
16.
Badagara
Kozhikode
17.
Kallai
Kozhikode
18.
Kadalundi
Kozhikode/ Malappuram
Wetlands of Kerala
19.
Tirur
Malappuram
20.
Chetwai
Thrissur
21.
Edappalli
Ernakulam
22.
Panangad/Kumbalam
Ernakulam
23.
Kannamali
Ernakulam
24.
Puthuvypin
Ernakulam
25.
Aroor
Alapuzha
26.
Kumarakom
Kottayam
27.
Asramom
Kollam
28.
Veli
Thiruvananthapuram
The unique wetland ecosystems of Kerala (table 2.9) include marshy and waterlogged
areas and vast Polders (paddy cultivating areas) associated with the backwaters and
lakes (which also store the flood waters and storm waters) and the Myristica Swamps
in the Western Ghat forests. About 53 patches of Myristica swamps have been recorded
from the Kulathupuzha, Anchal forest ranges and Shendurny Wildlife Sanctuary of the
Kollam and Thiruvananthapuram districts of Southern Kerala.
Table 2.8: Unique Wetland Ecosystems of Kerala (CED, 2003a)
No.
1.
2.
3
4.
5.
Ecosystem
Kuttanad Paddy fields
Pokkali Lands
Kol Lands
Kaippad lands
Myristica Swamps
District
Alappuzha
Ernakulam
Thrissur
Kannur
Kollam/ Thiruvananthapuram
Wetlands of international/national importance in Kerala:
Vembanad-kol, Ashtamudi and Samsthamkotta, are the three designated Ramsar
sites of Kerala. In addition to this, two more wetlands - Kottuli in Kozhikode District
and Kadalundi in Kozhikode and Malappuram Districts - have been identified by the
Ministry of Environment and Forests, Government of India, under National Wetland
Conservation Programme. The Ministry, in 2004, had approved a programme to prepare
Management Action Plan for Kottuli Wetland. The components include mangrove
afforestation, pollution abatement, fishery development, social interventions and
monitoring and evaluation which have been formulated and implemented with multiinstitutional participation.
Wetlands of Kerala
''
2.1.7. Institutional Structure, Policies and Legislation
At the International level, Wetlands International is providing necessary institutional
support to various wetland conservation activities in different countries. It is an
independent, non-profit, global organization, supported by Government membership
from all continents of the world, extensive specialist networks and volunteers. It
currently works through 15 country offices in Central and Eastern Europe, Africa,
South, East and North Asia, Oceania and South America; with its head office in
Wageningen, the Netherlands. Wetlands International has adopted the following four
long-term, strategic global goals to provide direction to its future work.
i)
Stakeholders and decision makers are well informed about the status and
trends of wetlands, their biodiversity and priorities for action,
ii)
The functions and values of wetlands are recognized and integrated into
sustainable development,
iii)
Conservation and sustainable use of wetlands is achieved through integrated
water resource management and coastal zone management, and
iv)
Large scale, strategic initiatives result in improved conservation status of
species, habitats and ecological networks
The MOEF, GOI is the apex body at the national level to co-ordinate the activities
related to Wetland Management in the country. At State level, the Department of
Environment and Forests or Department of Science and Technology is in charge of the
wetland management activities in the respective States. Realising the importance of
wetlands and developing an inter-sectoral framework for conservation of wetlands, a
National Committee on Wetlands was constituted. State Steering Committees have
been constituted in all the concerned States under the chairmanship of Chief Secretary
having members from various subject matter departments relating to wetland
conservation in the State.
They also include NGOs, academicians and representatives of stakeholders, including
member from the Ministry. This model has worked out very well as all conflicts within
various departments concerning wetland issues are resolved under the chairmanship
of the Chief Secretary of concerned State Government. Under the National Wetland
Conservation Programme, 94 sites have been identified for conservation in the country,
49 being recently added to the conservation list including 35 mangroves, 4 coral
areas and 10 urban lakes. Identification of these wetland sites is based on Ramsar
criteria which include aspects of waterfowl population, dominance of various plant/
animal species, biodiversity values, cultural aspects, religious and sacred sanctities,
socio-economic aspects, sustainable fisheries, traditional knowledge and other such
issues. Furthermore, in the proposed National Wetland Strategy, a great deal of
Wetlands of Kerala
emphasis has been given to the significance of wetlands for water supply, coastal
protection, and food security and livelihood improvements of the wetland dependent
people.
A number of R&D organizations in the State are involved in the study of various
aspects of wetlands. Interestingly the different wetland units are under the
administrative control of different departments and agencies in the State. The Kerala
Forests and Wild Life Department is in charge of the mangrove areas and the fresh
water lakes, backwater areas, reservoirs, etc., are under the administrative control of
Water Resources Department. The Science and Technology Department is cocoordinating the Coastal Regulation Zone activities which also includes the mangrove
areas.
The Ramsar Convention is a historical Convention in many respects particularly, as
it is one of the oldest ecosystem specific Conventions that speaks of wise use of
wetlands and not conservation alone. India is also a signatory to the Ramsar Convention.
As a part of the conservation strategy a data book called Montreaux Record is kept of
all those wetlands that require international help for conservation. The inclusion of a
site in this list makes it eligible for a global package for conservation related activities.
It also enjoins the Parties to the Convention to formulate and implement their planning
so as to promote the conservation of listed wetlands and as far as possible, the wise
use of wetlands in their territory (Art 3.1). The review of legal and institutional issues
related to wise use of wetlands is mandated further by the Additional Guidance for
the implementation of the wise use concept (I-2 of the Additional Guidance).
The Major Legislations in India Related to Wetlands are:
i)
The Indian Forest Act,1927
ii)
The Indian Fisheries Act, 1897 as amended by Indian Fisheries (Madras
Amendment) Act, 1927.
iii)
The Port Trust Act, 1963
iv)
The Wildlife Protection Act (WPA), 1972
v)
The Water (Prevention and Control of Pollution ) Act, 1974
vi)
The Water Cess Act, 1977
vii) The Air (Prevention and Control of Pollution ) Act, 1981
viii) The Forest (Conservation) Act, 1980
Wetlands of Kerala
Box 2.2: Criteria for identifying wetlands of international importance
Group A of the Criteria (Sites containing representative, rare or unique wetland
types)
Criterion 1: A wetland should be considered internationally important if it contains
a representative, rare, or unique example of a natural or near-natural wetland type
found within the appropriate biogeographic region.
Group B of the Criteria. (Sites of international importance for conserving biological
diversity)
Criteria based on species and ecological communities
Criterion 2: A wetland should be considered internationally important if it supports
vulnerable, endangered, or critically endangered species or threatened ecological
communities.
populations of plant and/or animal species important for maintaining the biological
diversity of a particular biogeographic region.
plant and/or animal species at a critical stage in their life cycles, or provides refuge
during adverse conditions.
Specific criteria based on waterbirds
Criterion 5: A wetland should be considered internationally important if it regularly
supports 20,000 or more waterbirds.
supports 1% of the individuals in a population of one species or subspecies of
waterbird.
Specific criteria based on fish
a significant proportion of indigenous fish subspecies, species or families, life-history
stages, species interactions and/or populations that are representative of wetland
benefits and/or values and thereby contributes to global biological diversity.
Criterion 8: A wetland should be considered internationally important if it is an
important source of food for fishes, spawning ground, nursery and/or migration path
on which fish stocks, either within the wetland or elsewhere, depend.
Specific criteria based on other taxa
supports 1% of the individuals in a population of one species or subspecies of wetlanddependent non-avian animal species.
Adopted by the 7th (1999) and 9th (2005) Meetings of the Conference of the
Contracting Parties, superseding earlier Criteria adopted by the 4th and 6th Meetings
of the COP (1990 and 1996), to guide implementation of Article 2.1 on designation
of Ramsar sites.
Wetlands of Kerala
ix)
The Environment Protection Act, 1986
x)
The Coastal Regulation Zone Notification,1991
xi)
The Environmental Impact Assessment Notification, 1994
xii) The Municipal Solid Wastes (Management and Handling) Rules, 2000
xiii) The Biodiversity Act, 2002
xiv) The Coastal Aquaculture Authority Bill, 2004
The Environment (Protection) Act, 1986, is an umbrella Act, which was enacted
with the objective of protecting and improving the environment and for matters
connected therewith. Environment as defined in Section 2 of the Environment
(Protection) Act included water, air and land and the interrelationship which exists
between water, air and land and human beings and other living creatures, plants and
micro-organisms and property. This Act has been instrumental in protecting wetlands
and groups of wetlands. Several significant regulations and notifications have been
passed under this broad Act for monitoring pollution and safeguarding the environment.
The Coastal Regulation Zone Notification, 1991 which in fact imposes restrictions on
industries, operations and processes in the coastal zone areas (500 meters from the
High Tide Line and the area between the High Tide Line and the Low Tide Line) has
been issued under this Act. The Environment Impact Assessment Notification of 1994
was also issued under this Act. Section 3 of the Environment (Protection) Act deals
with the power of the Central Government to take measures to protect and improve
the environment. The section reads as follows:
Section 3 (1) Subject to the provisions of this Act, the Central Government shall
have the power to take all such measures as it deems necessary or expedient for the
purpose of protecting and improving the quality of the environment and preventing,
controlling and abating environmental pollution. Such measures may include:
Section 3 (v) restrictions of areas in which industries, operations and processes or
class of industries, operations or processes shall not be carried out or carried out
subject to certain safeguards.
There are four key policies relating to environmental protection in India. They are:
•
The National Forest Policy, 1988
•
The Policy statement for Abatement of Pollution, 1992
Wetlands of Kerala
!
•
The National Conservation Strategy and Policy Statement on Environment and
Development, 1992
•
The National Environment Policy, 2006
There are also provisions in the Indian Penal Code for environmental protection.
The Indian Penal Code has a chapter on offences affecting Public Health, Safety,
Convenience (Chapter XIV). Sec. 268 provides that a person is guilty of a public
nuisance who does any act or is guilty of an illegal omission which causes any common
injury, danger or annoyance to the public or to the people in general who dwell or
occupy property in the vicinity, or which must necessarily cause injury, obstruction,
danger, or annoyance to persons who may have occasion to use any public right.
The section further explains that a common nuisance is not excusable on the ground
that it causes some convenience or advantage. Other concerned provisions are: a
negligent act likely to spread infection or disease dangerous to life (Sec. 269 I.P.C.),
a malignant act likely to spread infection or disease dangerous to life (Sec. 270
I.P.C.), making atmosphere noxious to health (Sec. 278 I.P.C.).
Various acts, rules and regulations that have been passed by the State of Kerala
regarding the governance of the water resources. Important ones among them are:
i)
The Travancore Cochin Public Health Act, 1955.
ii)
The Travancore Cochin Irrigation Act, 1956
iii)
The Travancore - Cochin Fisheries Act, 1956.
iv)
The Kerala Land Reforms Act, 1963
v)
The Kerala Land Utilization Order, 1967
vi)
The Kerala Panchayat Raj Act, 1994
vii) The Dam Safety Act-2000
viii) The Kerala Ground Water (Control and Regulation) Act, 2002
ix)
The Kerala Protection of River Banks and Regulation of Removal of Sand Rules,
2002
x)
The Kerala Irrigation and Water Conservation Act 2003
xi)
The Kerala WaterPolicy (draft), 2007.
"
Wetlands of Kerala
2.2 MAJOR MANAGEMENT ISSUES
The wetlands in Kerala are currently subjected to acute pressure owing to rapid
developmental activities and indiscriminate utilization of land and water. As a result,
the system is being degraded, especially in the tropics, at an alarming rate of around
one percent per year. Though there were no quantitative estimates on the rate of
destruction of wetlands in Kerala, the qualitative degradation of the ecosystem is,
more or less, well understood. The major issues facing the wetlands of Kerala are
mainly related to pollution, eutrophication, encroachment, reclamation, mining and
biodiversity loss.
The unscrupulous exploitation of the fragile wetland system and undesirable input
of residues exceeding the wetlands assimilative capacity is now increasingly resulting
in various kinds of pollution in the wetland system of Kerala. Eutrophication, which is
defined as the nutrient enrichment of waters stimulates an array of symptomatic
changes. Encroachment and Reclamation of wetland for various activities along with
unauthorized occupation is continuing in the wetlands from time immemorial. Major
resources of the wetlands which are being unwisely harvested are sand, lime shell,
fish and other bioresources. The threats to wetland biodiversity are at an all time high,
caused by detrimental human activities. Our mismanagement of land and water is
reflected in the decline we see today in the extent and quality of wetlands and the
important biodiversity they support.
The major issues identified for the wetlands of Kerala are analysed here using the
DPSIR framework of reporting (Fig. 2.2).
2.2.1 Driving Forces
The degradation of the major wetlands of Kerala has been driven by various direct
and indirect forces. The major driving forces of wetland degradation are: (i) population/
households growth and urbanization, (ii) industries (iii) infrastructure (iv) agriculture
(v) aquaculture (vi) fishing (vii) poaching (viii) mining (ix) deforestation (x) services (xi)
water transport and xii) tourism.
2.2.1.1 Population/household growth and urbanization
The human settlements were traditionally concentrated around the wetland systems
and the reasons for this are obvious. According to the census data (2001), the
population in Kerala doubled over five times in the last century (6 million in 1901 to 32
million in 2001) whereas Indias population could grow slightly more than three times
(238 million in 1901 to 1027 million in 2001). However, the trend has changed now
Wetlands of Kerala
#
and Kerala has registered the lowest growth rate during 1991-2001 among 35 States
and Union Territories in India. The population growth rate in Kerala during the last
decade works out to be 9.42 per cent (for the whole India it is 21.34%), the lowest
after the formation of Kerala State.
D RI VIN G FO R C ES
P opulation/households
growth and urban iza tion;
Industries;
Infrastru cture ; A griculture;
A quacu lture ;
F ishi ng; Poaching; M inin g;
De fore station; Se rvices;
Water tra nsp ort and
To urism
R ES PO N SE S
Le gal a nd instituti onal
re view ;
Re sea rch an d De velopm ent
Initiati ves;
P eople ’s M ovem ents
P RE SS U RE
In du strial eff luen ts;
R etting o f coco nut husk ;
Leach ates fro m ag ricultu ral
field s; W aste disp osal;
Petro leum h yd ro carbo ns;
H yd raulic interv en sio n s;
Land use chan g es;
O v er exp loitation an d
Weed in festatio n .
IM PA CT S
ST A T E
D imi nuti on of
Biore sou rces; Speci es loss;
Food toxicity; W ate rborne
and zoono tic diseases;
O bstruct ion to n avigation;
De crease in agri cult ure
production and produc tivity;
F lood a nd drought;
A esthe tic value depletion
Pol luti on and
e utrophicat ion;
Encroa chme nt,
rec lam ation and mining;
Biodiversity
Fig. 2.2 : DPSIR framework for wetlands of Kerala
$
Wetlands of Kerala
The present trend in Kerala is a shift from joint family to nuclear families resulting
in increase in households. According to the census data, the number of households in
Kerala has increased from 55 lakh in 1991 to 67 lakh in 2001. The average size of
households in the State has declined from 5.3 persons to 4.7 persons during this
period.
Rapid urbanisation and the consequent development of infrastructure have taken a
heavy toll to the wetlands. The urban sector in Kerala comprise of five Municipal
Corporations and 53 Municipalities. Unlike the other parts of the country, the
urbanization in Kerala is not limited to the designated cities and towns. Barring a few
Panchayats in the hilltracts and a few isolated areas here and there, the entire State
depicts the picture of an urban- rural continuum. Given the level of modern activities,
a good number of people engaged in traditional activities found them being gradually
marginalized from the mainstreams of the economy. This has created a lot of livelihood
insecurities and led to large-scale migration of people into cities and towns in search
of different kinds of jobs. According to 2001 census, 25.97% of the population lives
in urban areas. During 1981, it was 18.74%. Interestingly, most of these urban areas
are lying adjacent to major wetland systems. All Municipal Corporations except Thrissur
are very close to the important wetland systems of the State.
The increase in population and households and urban expansion thus becomes
major driving forces for most of the wetland issues identified. The urban expansion
requires more wetland areas to be converted resulting to ecosystem changes and
biodiversity loss. The household activities harmful to the wetlands include more waste
generation and disposal to the wetland system, direct/indirect defecation, small scale
encroachment and reclamation, mining and destruction of biodiversity.
Fig. 2.3 Wetland reclamation for housing
Wetlands of Kerala
%
2.2.1.2 Industrial development
Industrialization, in the past century was considered as the major activity for solving
the unemployment problem in the State. For promoting industries, exemptions were
given, especially in environmental management related activities. Thus, many small,
medium and large modern industries emerged on the banks of the backwaters and
rivers and they dump their wastes into the waterbed in an attempt to save the costs
of pollution abatement. A good number of large, small and cottage industries are now
located near the wetlands and drainage basins of Kerala. The Aluva Kalamassery
belt is one of the major industrial area of Kerala located adjacent to Vembanad wetlands.
The major industries adjacent to the wetlands include various chemical industries,
paper, Aluminium, refinery, ceramic, spinning mills, match factories, cashew processing,
milk pasteurization, etc. Coir units are the main small scale industry in the coastal
belt. In addition there are many small scale units like fish processing, food processing,
motor and welding workshops, etc., functioning adjacent to many of the wetlands.
2.2.1.3. Infrastructure development
The infrastructure development activities are in full swing in Kerala in the areas
adjacent to the major wetlands and drainage basins, for many years. The major activities
include construction of roads, bridges, dams, railway lines, air ports, harbours and
ports, landing centres for water transport, commercial and residential buildings etc.
The construction activities are the need of the day, but what is lacking is proper
development planning and environmental monitoring in almost all the cases. Most of
the activities create some kind of interventions in the system causing degradation.
2.2.1.4. Agriculture
Agriculture expansion accompanied by intensive use of agrochemicals has become
a major driving force for wetlands causing encroachment, reclamation, pollution,
eutrophication, and biodiversity loss. Paddy cultivation is prevalent in the low land
areas like Kuttanad, Kole, Pokkali and Kaipad lands. Mixed cultivation with coconut as
main crop is also predominant in many wetland areas. Vegetable cultivation is also
common in summer season in many parts of the reservoirs and river banks. The
catchment areas of most of the wetlands are cultivated mainly with rubber, coconut,
pepper, tapioca, plantain, mixed vegetables, etc.
2.2.1.5. Aquaculture
Like agriculture, aquaculture has also various dimensions and scales of operation in
the wetlands of Kerala and has become a driving force for pollution, eutrophication,
Encroachment, and Biodiversity loss. Most of the aquaculture farms are using
commercially available organic and inorganic feeds and are using artificial techniques
for filtration. In earlier days rice cultivation and shrimp farming (Chemmeen kettu)
&
Wetlands of Kerala
were done alternately in the same areas, during the natural infiltration periods. Recent
developments in the field of aquaculture, especially culture of high valued species like
shrimp has brought aquaculture under the focus of attention of the people in general
and the entrepreneurs and exporters in particular. Aquaculture is also practiced in
many of the inland wetlands, like ponds, reservoirs, etc. This includes integrated fish
culture in reservoirs and larger ponds and culture of Tilapia, Catfish, Ptunis, etc., in
family ponds.
2.2.1.6 Fishing
Backwater fishing is one of the major economic activities of the rural coastal
communities. In the inland wetlands, fishing is mainly an alternate income generation
activity. The current level of inland (including backwaters and estuaries) fish production
of Kerala is to the quantum of about 75000 tones/year (www.kerala.gov.in/
dept_fisheries/dept_fisheries.htm). The population engaged in this sector in Kerala is
currently 2, 51,482 of which 41,223 are active fishermen. Overexploitation of the
fishery resources is a major threat to the wetlands now.
Fig. 2.4: Brahminy Kite - found killed in a wetland
Photo courtsy: Nameer P.O. (KAU)
Wetlands of Kerala
'
2.2.1.7 Poaching
Intensive poaching of water birds, including migratory birds for food is one of the
major threats to the birds of wetlands. Poaching is carried out using shotguns and
poison.
2.2.1.8.Mining
The state of Kerala is blessed with large deposits of black sands (containing ilmenite,
monazite, rutile and zircon) glass sands (pure silica) , clays, bauxite, iron-ore, lime
stone, graphite, lime shell (raw material for white cement) and river sand (construction
material). The occurrence of these deposits are controlled by specific geological
formations consisting of crystalline rocks including charnockite, khondalite and the
Sargur group; sedimentary rocks of Tertiary age, laterite cappings on crystallines and
sedimentaries, and subrecent to recent sediments. Even though all the above deposits
are available, the mining activities are restricted to black sand, glass sand, clays,
laterites, lime shell and river sand.
Fig. 2.5: Sand Mining
Wetlands of Kerala
In order to meet the demand from the construction sector, indiscriminate mining of
sand from the river basins, estuaries and even paddy fields are practiced in almost all
areas. The Licenses for sand and shell mining are given by the Local Self Government
Institutions in almost all river basins. Mining will not be a major issue, if we adopt a
scientific method of exploitation of resources.
Another major mining activity in the coatal wetlands is for the collection of lime
shell for industrial purposes. The traditional lime shell mining has little effect to the
wetlands. But recently, the industrial sector has started in-depth (upto 7 m) lime shell
mining in Vembanad Lake using mechanical devises which is an emerging threat to
the system.
2.2.1.9 Deforestation
Due to various pressures and continuous onslaught, the extent of forests dwindled
during the 19th and 20th centuries. In 1905, forests covered 65 percent of Kerala. An
estimate on the changes in forest cover in the southern part of the Western Ghats
using satellite data, between 1973 and 1995 by Jha et al (2000) showed a loss of
25.6% in forest cover over 22 years. The dense forest was reduced by 19.5% and
open forest decreased by 33.2%. As a consequence, degraded forest increased by
26.64%. According to official sources, the States forest accounted for 27.83 percent
of its land area (GOK, 2006). The vanishing forests cover in the watershed of the
rivers leading to soil erosion and subsequent siltation and eutrophication problems in
the wetlands.
2.2.1.10 Services
The activities related to services comprise water supply, sanitation, irrigation,
electricity, etc. Most of these activities require interventions in the wetland system in
various ways, causing threat to the system
2.2.1.11 Water transport
The water transport system is intended for providing facilities for transport and
cargo transportation at cheaper rates to the people residing in the water logged areas
and is provided mainly by the State Water Transport Department (SWTD). There are
also some private operators in this field. Mechanized boats are mostly used for the
purpose. The inland water transport system in Kerala consists of 1895 kms of
waterways. This includes navigable river, backwaters and manmade cross canals.
2.2.1.12. Tourism
The national and international leisure industry has introduced many measures to
promote tourism related activities in the wetlands. Wetland tourism is now progressing
Wetlands of Kerala
in Kerala concentrating the backwaters, reservoirs, lakes and major ponds. The main
attractions in almost all the cases are house boats, majority of them are mechanised.
The unimpeded tourism activities contribute to the increased pollution, eutrophication,
encroachment, reclamation, mining and biodiversity loss in the wetlands.
2.2.2 Pressures
The outputs from various activities in the land and water exert heavy pressures on
the system and become threats to the sustainability of the system. The major pressures
identified are from (i) industrial effluents (ii) retting of coconut husk (iii) leachates
from agricultural fields (iv) waste disposal (v) petroleum hydrocarbons (vi) landuse
changes (vii) hydraulic intervensions (viii) overexploitation of resources and (ix) weed
infestation.
2.2.2.1. Industrial effluents
The effluents from the industries situated on the banks of the rivers and wetlands
are the main sources of chemical pollution of wetlands of Kerala. These effluents
contain a large number of toxic ingredients such as acids, alkali, heavy metals,
suspended solids and a number of other chemicals, which have immediate and longterm effects on the organisms. Several estuarine and river systems in Kerala are now
hot spots of heavy metallic pollution. Depending on the natural and anthropogenic
inputs in an area, the association of heavy metals varies with different fractions of
the sediments.
2.2.2.2. Retting of coconut husk
Coconut husk retting, a widespread activity causing organic pollution of the wetlands
of Kerala, results in release of, large quantities of organic substances like pectin,
petosan, fat and tannin are liberated into the water by the activity of bacteria and
fungi. The decomposition of pectin results in the production of hydrogen sulphides the basis of the nauseating smell in and around retting zones. High organic content (613%), high BOD (5,137 mg/1), low oxygen (0.05 ml/l) and high sulphide (4.97 mg/1)
characteristic of retting zones are found to be devastating for the bottom fauna.
Fig. 2.6: Coconut husk retting
Wetlands of Kerala
2.2.2.3. Leachates from agricultural fields
Wetlands, usually found adjacent to paddy fields and there is great likelihood that
human habitations develop in adjacency to these wetland ecosystems. The present
intensive agriculture practices are using large quantity of both inorganic and organic
fertilizers and pesticides. The fertilizers and pesticides being applied in the paddy
fields and home gardens, ultimately reach the wetlands during rainfall and floods. The
intensive aquaculture farms also using commercially available feeds, the excess quantity
of which is reaching the wetland system causing eutrophication problems.
2.2.2.4 Waste disposal
Municipal solid waste and sewage are the major pollutants of almost all wetlands
in the State, and are the main sources of pathogens in the system. There is no
sewerage system in any of the cities and towns in Kerala, except for a partial system
in Thiruvananthapuram City, where there is no proper sewage treatment plant. So
ultimately, the waste reaches the Parvathy Puthanar, a river running along the western
edge of the City. The urban wastes include hospital wastes, market and slaughter
house wastes and sewage and wastes generated from other commercial and residential
areas including overflow from latrines. It also contains large quantities of non-degradable
solid wastes, mainly plastic bags and containers. There is no proper hospital waste
management system for most of the major hospitals, including the government medical
colleges.
Fig. 2.7: Municipal solid waste in wetlands
Wetlands of Kerala
!
Fig. 2.8: Plastic wastes in canals of Kochi
Fig. 2.9: Solid wastes disposed in bundles
"
Wetlands of Kerala
The people living near the wetlands in the rural stretches are also depositing the
household wastes into the system. Hanging latrines (with outlet directly to water
body) are common scene in the banks of most of the wetlands. According to an
estimate the latrines of about 60 per cent of houses near to the wetland areas and
canals are directly or indirectly opening into the wetlands. There is no proper slaughter
house waste management practices in most of the cities and rural areas. The present
practice is to dump the wastes in the sides of wetlands or rivers during night. The
infrastructure development activities in the State along the sides of the wetlands
generate a huge quantity of debris which consists of organic and inorganic materials
and toxic compounds like cement, clay, wood, oil grease, paints, insect repellent
substances, etc. A good quantity of these, are dumping directly into the wetlands.
The tourism activities in the wetlands generate large amount of wastes both in the
land and water. The wastes generated in the houseboats are directly reaching into the
system.
2.2.2.5 Petroleum hydrocarbon
The wetland ecosystem in Kerala is also threatened by petroleum hydrocarbon
(PHC) pollution. Numerous oil tankers and other vessels plying through the waters are
major sources of pollution. The input of PHC to the aquatic system is purely of
anthropogenic nature. It is found mostly in the form of unburned fuel and oil and the
tarry nature of these residues adheres to the respiratory system of aquatic organisms.
The oil spread as film over the water in Akkulam-Veli Lake system inhibits free exchange
of oxygen with atmosphere and light penetration resulting in impairment of primary
production. Oil and grease spills from the boats used for water transport, fishing and
tourism are other sources for PHC pollution. Wash out from the motor workshops,
bus stands, boat building yards, etc., situated on the outer reaches of the wetlands
and the construction wastes are also sources of PHC pollution.
2.2.2.6 Land use changes
The wetlands are currently subjected to acute pressure of rapid developmental
activities. Most of the government sponsored projects especially in urban areas are
finding space in wetland areas for which large scale reclamation is going on.
Unauthorized encroachment of wetland areas for non-wetland purposes are still
continuing in the State especially areas adjacent to low land paddy fields, mangrove
areas and other backwater areas. Initially most of the encroachments are for agriculture
purposes; later these areas were reclaimed and used for various other purposes.
The unscientific land use and agricultural practices along with forest clearing in
uplands and in wetland areas exert major pressure on wetlands leading to soil erosion.
This causes siltation leading to vertical shrinkage and related problems like salinity
Wetlands of Kerala
#
intrusion, ecosystem change and biodiversity loss. The eroded soil contain large amount
of nutrients which causes eutrophication. Utilization of low lands for purposes other
than the originally envisaged, like paddy lands for vegetable cultivation, aquaculture,
etc., are common practice in many places, which lead to the change in the ecosystem
Reclamation of the private owned low land areas for construction purposes, for
industries, etc., are common activities in many places. In addition to this, some areas
are excavated for clay and soil for making country bricks. The wetland loss due to
various anthropogenic activities has been responsible for bringing to the verge of
extinction of countless species of medicinal and economically important plants and
animals.
2.2.2.7. Hydraulic interventions
Most of the hydraulic interventions in the rivers and wetlands are for providing the
basic needs of the people like drinking water, electricity and for providing suitable
condition for agriculture and fisheries. These create changes in ecosystem and related
issues.
Box 2.3: Hydraulic Interventions in Vembanad
Wetland System
One can identify roughly four hydraulic hydrologic interventions
within the entire Vembanad wetland system. The first and the oldest
was the reclamation and creation of the Wellington Island and the
Shipping channel maintained near the Kochi mouth., Then came the
major reclamation and bunding works in the Kuttanad area for improving
agriculture in the area. This started about a century ago and came virtually
to a halt four or five decades ago. The third intervention was the
construction of the Thottapally spillway (1955) to divert floodwaters of
Achankovil, Pamba, Manimala and Meenachil directly to the sea. The
last intervention was the Thanneermukkom barrier (1975) built to prevent
salinity ingress into the Kuttanad agricultural area during summer. All
the above interventions, except the first significantly altered the original
flow pattern, salinity ingress, pollution dispersion and other
characteristics, turned out to be insufficient, requiring for the flood
prevention works. The capacity of the Thottappally Spillway especially
that of the leading channel, turned out to be insufficient, requiring for
the flood prevention works. As for the Thanneermukkom barrier, although
only 2/3rd of the originally designed numbers of gates were constructed,
yet this structure has fulfilled its envisaged function. The barrier has,
however led to social conflicts, especially between the fishermen above
the barrier and the Kuttanad farmer, since brackish water fish such as
prawns have disappeared upstream of the structure. In addition, the
barrier has reduced the flushing of pollutants and also increased pollution
in the stagnant waters upstream, including infestation with weeds.
$
Wetlands of Kerala
2.2.2.8. Overexploitation of resources
The unsustainable commercial exploitation of wetland resources exerts major
pressure on the system. The present practices in the fisheries sector have adverse
effect to the system like blocking the migratory pathways of fish and other organisms,
destruction of fish larvae, poisoning wetlands during capturing, etc. Even small sized
fishes were also caught for using as cattle feed.
Sand mining and mining of other resources like lime shell are carried out without
any studies or taking in to consideration the sustainability aspects. In addition to the
licensed mining, there are a lot of people engaged in illegal sand mining activities in
the wetlands and rivers.
Fig. 2.10: Aquatic weeds
2.2.2.9 Weed infestation
Increased trade and commercial activity has brought with it, a large number of
aquatic weeds, into this area. The excessive growth of weeds like Salvinia molesta,
Eichhornia crassipes and Damasonium flavum, etc., exerts great pressure on the
biodiversity of wetlands. The alien weeds have found great competitive advantage
over the native aquatics.
2.2.3 State of Environment
2.2.3.1 Pollution and eutrophication
Most of the pollution sources are man made and include industrial effluents, sewage
and faecal disposal, pesticides and chemical fertilisers, retting of coconut husks,
slaughter house waste, domestic waste, etc.
Wetlands of Kerala
%
•
The pollution of wetland ecosystem in the State is considerably high especially
in Vembanad-Kol backwater system due to the various types of pollution in
the upstream area of Pamba, Achenkovil and Periyar rivers which ultimately
drain in to Vembanad-Kol backwater system as well as various anthropogenic
activities in the proximity of the backwater. The low water level in the summer
months in these rivers also lead to salinity intrusion in to the river water which
makes the river water unsuitable for drinking and other uses like irrigation.
The same situation prevails also in many other wetlands in the State.
•
The concentration of total metal content varies with location and sediment
texture. It also shows seasonal variation. The concentration of Hg, Pb, Zn, Cr
and Cd are found to be high in fine-grained sediments and low in sandy
sediments. The estuarine region also exhibit high organic carbon content,
especially at the point of effluent discharge. In general, the highest
concentration of heavy metals in sediments was observed during pre-monsoon.
During the monsoon season, the sediment exchange, a part of the exchangeable
phase of the metals, to the water column due to high influx from the rivers.
The high metal concentrations observed in Kochi harbour area during the premonsoon season are also attributable to the intrusion of high saline waters
and precipitation of particulate matter. The heavy metal pollution has a longterm impact, which is evident from Beypore estuary, where considerable
amounts of mercury has been found retained in the sediments even after the
stoppage of industrial effluent discharge.
•
Analysis of particulate metal content indicates high concentration of Zn, Cr,
etc., due to industrial pollution in Kochi region of the backwater system. The
benthic organisms such as mussels and oysters are found to have high
accumulation of zinc beyond the permissible limits. High concentrations of
Zn, Cu, and Fe were also observed in the backwater oyster, Crassostrea
madrasensis (Preston) from Kochi region. The distribution of trace metals (Cd,
Cu, Fe, Mn, Zn and Hg) in Crassostrea of Kochi region was found to exhibit
seasonal variation. The oyster is found to be a suitable indicator organism for
metal pollution in backwaters.
•
The pathogen limit in many of the wetland systems in the State seem to be on
the higher side, compared to the standards. These create a situation of drinking
water scarcity in many of the places where people are mainly depending on
wetlands for their drinking water needs.
&
Wetlands of Kerala
Fig. 2.11: Eichhornia crassipes
•
Many of the lake systems of Kerala are facing serious environmental problems
due to intense weed growth resulting from high degree of eutrophication. Due
to excessive eutrophication and the resultant weed growth, the Akkulam-Veli
backwater system is in the verge of total degradation. Other backwater systems
especially parts of Vembanad, Ashtamudi, etc., are also affected by excessive
weed growth. Aquatic weeds are characterized by spontaneous growth and
appearing without being sown or cultivated and also have high reproductive
capacity.
Fig. 2.12: Eutrophication process
Wetlands of Kerala
'
•
At present the prolific growth of two species of aquatic weeds, viz. Eichhornia
crassipes (Water Hyacinth) and Salvinia molesta (African Payal) has created
serious environmental problems in many wetland ecosystems of the State. In
fact, the prolific growth of Water Hyacinth has grown to the level of a difficult
managerial problem in backwaters. In most cases, upstream wetlands are
acting as a nursery - cum - store-house of this perennial weed, posing constant
threat to the native flora. Flash floods bring in mats of this aquatic weed,
masking the entire water body for days together. This prevents capture of
sunlight by the submerged plants for photosynthesis and hence even lead to
their total elimination. As a result, the common submerged and floating aquatic
plants, which are part of the local ecosystem, are gradually replaced by water
hyacinth. Plants facing threat and total elimination under this category include
Nymphaea, Nymphoides, and Vallisneria.
Fig. 2.13 Nymphoides indica
•
The aquatic plants and animal species are affected due to eutrophication
causing either their elimination or species change. The increased growth of
aquatic weeds, pollution of water, etc., has been obstructing the growth of
other aquatic plants and animals hindering the resource conservation.
2.2.3.2 Encroachment, reclamation and mining
•
Wetlands under extreme threat are more in Kerala than in any other State.
Studies carried out in recent years have pointed out the unfavorable changes
taking place in the physical, chemical, biological and geological environment
of the wetlands. Segmentation of wetland by constructing bunds, dredging,
reclamation and consequent shrinking have been implicated as major reasons
Wetlands of Kerala
Box 2.4: Kuttanad, the Rice bowl of Kerala
The Kuttanad landscape comprises around 1100 km2 of which about 304 km2
lies below sea level. The land, which is presently inhabited by human population, is
developed by reclaiming the waterlogged areas over the years. Kuttanad is drained
by a network of rivers and man-made channels. The main feature of the drainage
system is the Vembanad Lake that was formerly a large lagoon. The tidal flow into
this lake is controlled by a regulator at Thaneermukkom. This network of canals and
bunds throughout its entire extent gave it the sobriquet Holland of Kerala.
The landform of Kuttanad comprises of Kayalnilangal, Karinilangal and
Karappadangal. Kayalnilangal comes to around 8,100 hectares while Karinilangal
around 6,075 ha and Karappadangal around 42,505 hectares. Kayalnilangal is below
the sea level. Though the soil is acidic, if the saline intrusion is prevented, the area
can be utilised for paddy cultivation twice in a year. Karinilangal is waterlogged and
due to the presence of high acidity, this contributes only very little to the cultivable
land. Karappadam is the land, which has been reclaimed over the years. North
Kuttanad, mid Kuttanad, upper Kuttanad and Kuttanad comprises the Karappadams.
This is comparatively fertile and is less affected by saline water intrusion. North
Kuttanad is prevented from salt intrusion by the Thaneermukkom Regulator.
The water inflow of Kuttanad is mainly controlled by four river systems originating
from the Western Ghats region viz., Meenachil, Manimala, Pamba and Achenkovil,
which ultimately drain into Kuttanad. Hydroelectric and irrigation projects in these
rivers determine the water flow to the Kuttanad. The human interventions and resulting
land use changes in the upstream of these rivers cause serious consequences in the
ecological conditions of the downstream areas.
The total basin area of these four rivers comes to around 5838 km2. The
floodwaters enter Kuttanad from the upstream catchments during the monsoon period.
The floodwater from these rivers carries considerable sediment load that spreads out
on the lowland. During high floods water overflows bunds over to the roads and
homesteads and cause serious havoc.
Farmming is the main occupation of the people of Kuttanad. Paddy cultivation
predominates in the low land. Coconut palms are planted on bunds and reclaimed
lands. The extent of coconut cultivation is increasing. Pepper, banana and yarms are
also cultivated in certain areas. The reclamation of land for habitation and raising
homestead cultivation has reduced the available area for floodwater storage, which
results in the rise of flood levels.
The problem of Kuttanad is mainly attributed to the mismanagement of its
hydrological regime. When the development was under way, hydrological aspects
were not given due consideration which finally resulted in its present ecological
crisis.
The area suffers regularly from:
•
Flooding and salt-water intrusion which limit the growing season to a few
months
•
Lack of drinking water in the dry season because of salinity intrusion,
various types of pollution etc.
•
Lack of dry land to build settlements, leading to very high population
densities on the reclaimed bunds
•
Poor road network because of the number of criss-crossing water courses,
leading to a dependence on water transport
Wetlands of Kerala
for the habitat destruction and dwindling of resources.
•
Erstwhile Government of Travancore encouraged the farmers to reclaim
Vembanad backwater in the Kuttanad region for paddy cultivation. In the
initial stages of these reclamations, according to an estimate in 1834, Vembanad
backwater had a total area of nearly 36500 ha. (Gopalan et al, 1983). A total
area of 23104.87 ha, has been reclaimed from the backwaters for the purpose
of paddy cultivation, paddy cum-shrimp culture and coconut husk retting during
the period between 1834 and 1975. This brought about a horizontal shrinkage
of around 64 per cent of the total area of the Vembanad backwaters.
•
The aspiration for raising two or more crops of paddy in the reclaimed area in
Kuttanad, Government constructed a spillway for flood control at Thottapally
in 1955 and a barrier for checking the intrusion of saline waters
atThanneermukkom (commissioned in 1974). This has ecologically severed
nearly 6900 ha of brackish water lying south of Thanneermukkom from the
main body of Vembanad backwater system.
•
Projects for developing Cochin Harbour (1920-1936), Fishery Harbour (1978),
Integrated Project for the Development of Cochin Port, Urban Development
Project of the Greater Cochin Development Authority (G.C.D.A) and Town
Planning Trust (1981-1985) and such other activities claimed a total wetland
area of 720 ha, from the Vembanad backwater of Kochi region. Thus it is
amply clear that, though the conversion of wetlands began in 1834, major
reclamations were carried out in the course of past hundred years during
which Vembanad backwater reduced itself from an area of 36500 ha to 12675
ha. i.e., 35%.
•
The loss of Mangrove area associated with the backwaters of Kerala, due to
encroachment and reclamation is not correctly estimated. According to Chand
Basha (1992) during the last century, the reduction was from around 700 sq
km to 17 sq km.
•
All the rivers of Kerala are now vulnerable to saline incursion. Efficiency of the
backwaters acting as a buffer zone between the sea and the rivers has declined
due to such aerial shrinkage.
•
The Vembanad backwaters in Kochi region and the coastal areas in Alappuzha,
Kayamkulam, Kollam, Paravur and Veli are identified as some of the hotspots
in the State. The Water Balance Study of Kuttanad conducted by the IndoDutch team reveals that about 90600 ha. (20%) of Kayal was reclaimed
between the years 1968-1983. Erosion, transportation and deposition of
sediments are natural processes controlled by mainly geologic, climatic, physical,
vegetative and other conditions throughout the geologic times. However, during
the present century, because of deforestation, manmade structures and change
in cropping system in the uplands, the rate of transport of sediment from the
Wetlands of Kerala
watersheds and their deposition in the wetlands have increased considerably.
This trend of erosion and sediment movement poses environmental problems
since, before adjusting to the equilibrium for the new conditions, additional
problems are encountered.
•
In the light of data on the shrinking backwaters, the Agency for Aquaculture
Development, Kerala (ADAK) carried out a realistic survey of the back waters
of Kerala in 1989 -90 with a view to assess the potential brackish water areas
suitable for aquaculture. The results of this survey have revealed that there
exists only a total area of around 65210 ha of brackish waters in Kerala,
including the fish farms and prawn filtration fields. This shows that the
backwaters of Kerala have undergone shrinkage of 73% percent of the originally
estimated 242600ha. This has to be taken seriously and strategy has to be
formulated for conservation and management of existing wetland areas with
local stakeholder participation.
•
The increase in sediment supply by the watershed will have its impact on the
watershed itself and on the river systems as well as wetlands. Water storage
space is often reduced by sediment accumulation. To avoid rapid loss in waterstorage capacity and consequent reduction in the life of wetlands, measures
may be introduced to reduce sediment inflow. The loss in water storage space
will change the entire ecology of the wetlands.
•
The forces acting upon a sediment particle brought to a wetland by stream
flow include a horizontal component due to the force of water acting upon the
particle in the direction of flow and a vertical component due to force of
gravity. A particle remains in suspension and is transported into a wetland so
long as turbulence exists, creating an upward force equal to, or exceeding,
that of the force of gravity. When a flow enters a wetland, the increased
cross-sectional area and wetted perimeter result in a decrease in velocity and
turbulence of the original stream flow. Eventually, these are dissipated over
large areas of the wetland and become ineffective as a transporting media.
The particle then settles to the bottom and is said to be deposited.
•
It is also possible that in some wetlands, the sediment inflow, upon entering,
retains its identity and transports the finer particle through certain length. This
results in greater percentage of the finer particles being transported
downstream. Where the incoming sediment load contains larger quantity of
coarse-grained materials or coagulated fine-grained materials, maximum
deposition occurs in the head-water area. The sand and gravel are deposited
first, progressively finer materials being deposited by the stilling effect of the
water body. Clays and colloids are transported for greater distances. Where
maximum initial deposition occurs in the head-water areas, the deposits advance
into the wetland basin with time. Excessive outflows cause this process and
stream flow erodes materials previously deposited at higher water stages and
transports them to lower elevations in the basin. The sediments in the coastal
Wetlands of Kerala
!
wetlands can also be from the sea, in which case the entire dynamics will be
different.
•
The availability of minable sand/lime shell in Kerala is not yet well studied and
doccumented. Amidst the strong intervention of the judiciary on the over
exploitation of river sand mining, Kerala could not come up with sensible
solutions on where and how much to be mined from each of the rivers available
in the state. Very little published data is available on the quantification of lime
shell and river sand mining, which is mostly the propriety of the respective
Grama Panachayats wherever these materials are available.
2.2.3.3. Biodiversity
Western Ghats of Peninsular India is one of the eighteen Global Hot Spots of
biodiversity. The diversity of climatic, edaphic and biotic regimes have shaped the
evolution of over 4000 taxa of angiosperms, 117 amphibians, 150 reptiles, 508 birds,
79 mammals and an unknown number of taxa from less studied groups. By virtue of
its unique location (sandwitched between the Arabian Sea on the west and the Western
Ghats on the east), topography (ranging from the coastal lowlands to mountain regions
intervened by vast expanse of undulating midlands) and high rain fall, Kerala provides
a wide variety of aquatic habitats like rivers, streams, pools, ponds, lagoons, estuaries
etc. harbouring unique types of vegetation of their own.
The wetlands of Kerala are treated as sites of exceptional biodiversity in the country
and are characterized by several endemic species. The coastal plains have been ravaged
since early times of human habitation and most of the land is now used for housing
and agriculture. Even these disturbed habitats are potential location for rapid speciation
has been amply proved from the long list of new taxa discovered and described form
here during the last two decades. Increased trade and commercial activity has brought
with it a large number of aquatic and wetland weeds into this area. Moreover, such
activities have also resulted in the creation of man-made reservoirs, abandoned granite
quarries and clay pits which, in course of time, have provided ideal habitats for aquatic
biota.
2.2.3.3.1 Flora
Though the benthic algae and other macro vegetation also contribute significance
to the primary production, in wetlands phytoplankton plays a major role and has
received much attention. The phytoplankton in the wetlands varies from freshwaters
to truly estuarine and marine species. Phytoplankton in coastal wetlands has
reproductive rates to offset their population, which is lost by the downstream drift.
Predominance of certain species depends on favorable conditions that facilitate their
rapid reproduction. There are many studies on the phytoplanktons of Kerala; most of
them are confined to the Ramsar sites. A total of 100species of phytoplanktons were
recorded from the backwaters of Kerala (Unnnithan et al, 2005). There are some
scattered studies by Madhusoodhanan and his students of Calicut University and
Panikker of SN College. A study on marine fungi of the Kerala coast was attempted
"
Wetlands of Kerala
by Ravindran (2003). A compilation all available data revealed the presents of about
90 species of Cyanobacteria, 275 species of marine/fresh water algae, 35 species of
aquatic fungi.
Joseph (2002) recognised the three groups of aquatic macrophytes in Kerala. The
first group, plants growing in running water are highly reduced, thalloid Podostemaceae
plants, growing attached to submerged rocks in mountain torrents and those and
plants like Aponogeton crispus, A. appendiculatus, Cryptocoryne consobrina and
Vallisneria spiralis etc generally growing in slow-flowing water like rivulets and canals
comes in this group.
The second group of plants growing in stagnant water can broadly be divided into
two subgroups: free-floating (eg members of the family Lemnaceae and Pistia stratiodes
of Araceae) and anchored (eg Ceratophyllum demersum, Eriocaulon setaceum, Hydrilla
vertcillata, Najas indica and some species of Utricularia etc). Among the anchored
hydrophytes four different types were recognised as follows: i) Anchored-submerged:
Blyxa aubertii B. octandra, Ottelia alismoides, Rotala cookii, R. vasudevanii and
Vallisneria spiralis etc, ii) Anchored-floating-leaved: Aponogeton nadans, species of
Nymphaea and Nymphoides and Sagittaria guayanensis are a few common examples
of this kind, iii) Anchored with floating or trailing shoots: They are somewhat
intermediate between the floating leaved and emergent types. Many of them have
specialised structural adaptations for this kind of life, such as swollen petiole, in
Eichhornia crassipes and Trapa natana, aerophores as in Ludwigia adscendens and
some species of Nymphoides, spongy internodes in Neptunia prostrata and floats as
in some species of Utricularia and iv) Anchored-Emergent hydrophytes: Important
representative of this group are: Aeschynomene indica, A. aspera, Acorus calamus,
Dopatrium junceum, species of Eleocharis, Bergia capensis, Hygrophila balsamica, H.
triflora, Damasonium flavum, Limnophila, Monochoria vaginalis, Sacciolepis interrupta,
Typha angustata and Wiesneria traindra.
The third group includes species belongs to several genera of diverse families seen
in the marshy areas.
Mangroves are the most important group of plants present in the coastal wetlands
of Kerala. The extent and health of mangroves have a marked influence on the migratory
species and the abundance of the offshore fisheries in Kerala. The prop roots of
mangroves penetrate deep into anaerobic mud flats and activate mineral cycling and
maintain productivity of the ecosystem. They also provide a suitable substrate for
sessile organisms of economic importance such as oysters. The crown of mangrove
species provides resting and nesting place for many birds. The flowers of the trees are
good source of honey for the honeybees, which are excellent pollinators.
There are clear evidences to show that very rich mangrove vegetation existed
along the coastal tracts of Kerala and once supported about 700 sq km of mangroves
along its Coast (Ramachandran et. al., 1986) and what exist now are only relics of the
past. The total in 1992 was estimated as 16.71 sq km (Chand Basha, 1992), distributed
Wetlands of Kerala
#
in the coastal districts of which Kannur (755ha) has the largest area followed by
Kozhikode (293ha), Ernakulam (260ha), Alappuzha (90ha), Kottayam (80ha),
Kasaragode (79ha), Kollam (58ha), Thiruvanthapuram (23ha), Thrissur (21ha) and
Malappuram (12ha). There is no detailed study thereafter regarding the extent of
Box 2.5: Mangalavanam
Mangalavanam is a wetland area dominated by mangroves near to the Kerala
High Court in Kochi city. The total protected area now is 3.44 ha, of which 2.74 ha
is core area. The area comprises of a shallow tidal lake in the centre with its edges
covered with thick mangrove vegetation. Mangroves are also present along the small
island in the middle of the lake. This water body is connected with Vembanad
backwaters by a canal. The area is well protected from natural predators and not
many similar communal roosting sites are available to birds in a crowded city like
Ernakulam. This site is crucial to the city dwellers also, since it serves as greenery in
the middle of the urban expanse. Apart from the much needed breeding and roosting
site for birds, the rare and threatened mangrove vegetation is preserved here.
Studies by Jayson (2001) recorded 41 species of birds representing 25 families.
The most common bird species found at Mangalavanam were Little Cormorant
(Phalacrocorax niger) and Black-crowned Night Heron (Nycticorax nycticorax). Out
of the 15 true Mangrove species available in Kerala coast, 9 are present in this small
area. A good number of mangrove associates are also present.
Even though considered a wetland area, it attracts a large number of species
from passerine group. Mangalavanam qualifies the criteria for declaring it as an
International IBA (Important Bird Area) of the Birdlife International due to the presence
of more than 1500 Little cormorant and the presence of more than 1000 Blackcrowned Night Heron, which form one per cent of the total global population.
In addition to birds, some other species of vertebrates like: Indian Flying Fox
(Pteropus giganteus), Painted Bat (Kerivoula picta), Three-striped Palm Squirrel
(Funambulus palmarum), House Rat (Rattus rattus), Bandicoot-rat (Bandicota sp.)
were also recorded from the area (Jayson, 2001).
The important conservation issues in this area are:
Accumulation of plastic wastes and invasion by weeds in the lake: Polythene
bags and floating waste materials enter the water during high tide and get entangled
among the aerial roots of mangrove in the lake, thus clogging the lake. Apart from
these, unwanted materials (including hardened cement bags from the nearby railway
store), are also found thrown in the lake. Invasion of the lake by various weeds,
particularly by Eichhornia during the monsoon (June to January) is another disturbance
to the mangrove community. These activities cause siltation in the lake. Finally this
may result in conversion into terrestrial land. This will seriously affect the food
availability of water birds.
Air pollution due to the unloading of cement bags: On an average, 70 trucks
operate in the nearby railway goods yard at a given time. The cement dust produced
from the unloading of cement is deposited on the vegetation of the area. This may
lead to the death or retarded growth of plants and trees.
$
Wetlands of Kerala
mangroves in Kerala. Mohanan (1999) estimated as it to be "less than 50 sq km".
The existing mangrove forests of Kerala are highly localizedand can be classified
into three categories.
i)
More or less undisturbed mangrove areas like Puthuvypin, Mangalavanam,
Kadalundi, etc.,
ii)
Degraded mangrove areas where there are still few patches of good mangroves
and where regeneration measures can be tried out. Areas like Kumarakam,
Asramom, Kunjimangalom and Kavvai belong to this category,
iii)
Completely degraded areas where regeneration is almost impossible. These
include areas, which had been already converted for various purposes like
ports, agriculture farms, built up areas, etc.
A recent investigation by Anupama & Sivadasan (2004) could identify 15 true
Mangroves belonging to 9 genera and 7 families and 49 Mangrove associates from
Kerala. The true Mangrove species listed by them are: Acanthus ilicifolius L., Aegiceras
corniculatum (L.) Blanco, Avicennia marina (Forssk.) Vierh., A. officinalis L., Bruguiera
cylindrica (L.) Blume, B. gymnorrhiza (L.) Savigny, B. sexangula (Lour.) Poir., Exocoecaria
agallocha L., E. indica (Willd.) Muell., Kandelia candel (L.) Druce, Lumnitzera racemosa
Willd., Rhizophora apiculata Blume, R. mucronata Poir., Sonneratia alba J. Sm. and S.
caseolaris (L.) Engler. The family Rhizophoraceae is the most represented one with 6
species belonging to 3 genera. This indicates fairly rich species diversity even in the
present, highly degraded condition. The true mangrove species are confined to the
salty-marshy environment along the backwaters and rivers, whereas the mangrove
associates were also found outside the mangrove environments.
Important mangrove associates are Acrostichum aureum, Aniseia martinicensis,
Alternanthera sessilis, Ardisia littoralis, Bacopa monnieri, Barringtonia racemosa,
Caesalpinia crista, C. nigra, Calophyllum inophyllum, Cerbera odollam, Clerodendum
inerme, Crinum defixum, Cyperus spp., Dalbergia candanatensis, Derris trifoliata, D.
scandens, Dolichandrone spathacea, Eclipta prostrata, Fimbristylis cymosa, F.
ferruginea, F. polytrichoides, Flagellaria indica, Heliotropium curassavicum, Ipomaea
campanulata, I. pes-capre, Lagenandra sp., Mariscus javanicus, Melastoma sp., Morinda
citrifolia, Pandanus ododartissimus, Parsonia alboflavascens, Paspalum distichum,
Phragmites karka, Premna serratifolia, Samadera indica, Sauropus bacciformis, Scaevola
sericea, Sphenoclea zeylanica, Syzygium travancoricum, Taliparithi tiliaceum, Thespesia
populnea, Tylophora tetrapetala, Wedelia chinensis, Zoysia matrella etc.
The unique Myristica swamps are one of the major biodiveristy rich wetlands in
Kerala. About 53 patches of Myristica swamps have been recorded by Kerala Forest
Research Institute (KFRI) from the Kulathupuzha, Anchal forest ranges and Shendurny
Wildlife Sanctuary of the Kollam and Thiruvananthapuram districts of Southern Kerala.
A total of 63 tree species and 97 species of shrub-herb-climber combine were
recorded from the Myristica swamps (Sabu & Babu, 2007). Many of the plants seen
Wetlands of Kerala
%
Fig. 2.14: Mangrove forest at Kannur
Fig. 2.15: Acanthus ilicifolius
&
Wetlands of Kerala
Fig. 2.16: Calophyllum inophyllum
here are endemic to Western Ghats. Two species of earthworms, three species of
crabs, ten species of fishes, thirty four species of amphibians, thirty three species of
reptiles, fifty eight species of birds and twenty one species of mammals have been
recorded as present in the swamps. In addition to this annelids and arthropods are
also being recorded.
Box: 2.6 : Myristica Swamps
From among the incredible diversity of ecosystems, there is rare fresh water wetlands
found in Western Ghats with unique assemblage of floral and faunal biodiversity. Popularly
known as Myristica swamps. These freshwater swamp forest ecosystem is confined to
low altitudes characterized by slow flowing streams of Western Ghats river systems.
Myristica swamps have been recorded from Goa, Karnataka and Kerala in India. Trees
belonging to a primitive family of angiosperms; "Myristicaceae" are the dominant tree
species of this unique wetland ecosystem. Most of Myristicaceae family members are
capable of producing aerial roots when faced with unfavorable conditions. Hence the
Myristica species found in these exceptional wetlands have adaptations such as knee
roots for the anaerobic condition of the swamps, and stilt root for anchoring the tree
species in damp soil. Other than Myristicaceae family species members of other families
such as Celestraceae, Diptereocarpaceae, Anacardiaceae, Xanthophyllaceae and others
are significant part of this swamp community. Ground vegetation is not dense and the
dominant ground vegetation is belonging to Araceae, Zingiberace and Acanthaceae families.
Some of these swamps are considered even as sacred groves and have thus ecoheritage
value. These swamps having variety of microhabitats which provides favorable conditions
for survival and procreation of many annelids, arthropods, molluscs, fishes, amphibians,
reptiles, birds and mammals. Many of these animals found in the Myristica swamps are
endemic and some are on the red-list of IUCN. More importantly this wetlands also play
a critical role in water storing and maintaining ground water level. Myristica swamps are
critically endangered ecosystem in Western Ghats.
www.wetlandsofindia.org:8080/wetlands/freshwater.jsp
Wetlands of Kerala
'
Fig. 2.17: Myristica swamps
2.2.3.3.2 Fauna
Zooplankton is a major group in the energy transfer at secondary level and plays an
important role in the secondary production of wetlands. Long-term variability of
zooplankton is significant to differentiate whether these fluctuations are due to natural
causes or due to man made changes. Incidence of specific plankton may prove to
play useful role in environment gradually management studies. Extreme mobility of
plankton and patchiness of plankton are certain constrains in assessing the effects of
man made changes. The study by Unnithan et al (2005) recorded 20 groups of
Zooplanktons in eleven backwaters of Kerala. Much diversity is observed during the
post monsoon season. Detailed studies in other wetland areas are lacking.
The backwaters and adjoining environments of Kerala have been famous for its
islands and fisheries. Fishes have evolved a diversity of life history pattern. Some
species are short lived, others live for decades. Even within a species, there may be
major variations in life history patterns exhibited by different populations living at
different geographic locations in the wetland.The wetlands are endowed with rich
and diverse fish fauna characterised by many rare, endangered and endemic species.
Out of the 170 and odd fresh water fishes reported from Kerala, the status of over 90
species has been red listed by the IUCN. Out of the above, 18 have been classified as
critically endangered facing serious risk of extinction; 31 species have been classified
as endangered of which 13 are endemic only to Kerala and 18 species have been
classified under vulnerable category.
!
Wetlands of Kerala
The prawn infiltration in the areas of Vembanad backwater together with the inundation
and movements of water in accordance with the micro-ebb and flood tidal regime of the
estuary is a unique feature. There has been a drastic change in the hydrography of the
estuary following the construction of Thottappally Spillway and Thanneermukkam Barrage.
The long stretches of coastal zones and its associated backwater and brackish water
bodies are habitats for many wetland avifauna. Wetlands of Kerala are on the central
Asian-Indian Flyway. Vembanad, Ashtamudi and Periyar lakes, Kulathoor, Purathoor and
Kadalundi river mouths, and jheels like Azhinijlam provide suitable habitats for many migratory
species. Terns, sea gulls, sandpipers, plovers, teals, etc., are some of the important avian
visitors. Besides several paddy fields like Kole lands in Thrissur and Kuttanad in Alappuzha
are places for avian visitors.
Out of the 475 species of birds of Kerala, 128 species are wetland dependant. Out
of which 52 (40.63%) are winter migrants, while 59 (46.09%) species have been
reported breeding in Kerala for sure. Around 5 % are vagrants which are essentially
oceanic/pelagic birds that are blown to the shores because of monsoon winds or
cyclone. According to Birdlife International (2003), Kerala has 16 threatened species
of wetland dependant birds, out of which five are vagrants. Out of the 16 species one
is Critically endangered, three are Vulnerable, while twelve are Near threatened species.
Endowed with wetlands, including inland wetlands such as lakes, reservoirs, ponds
and paddy fields, the North Malabar region is found to be of great conservation value
as they were habitats of 114 species of birds in the water bird census conducted
jointly by the Kerala Forest and Wildlife Department and the Malabar Natural History
Society. The preliminary report on the Census says that 75,683 birds consisting of
114 species belonging to 25 families have been counted from 65 sites where the
census was carried out. All the major wetlands from Purathur (Bharathapuzha estuary)
in the south to Manjeswaram in the north, in various categories such as sea shore,
estuaries, tidal mudflats, mangrove swamps, backwaters, brackish as well as fresh
water marshes, ponds, reservoirs, river banks and paddy fields, were covered for the
census. Birdlife International has stipulated certain criteria for identifying IBAs. In the
case of congregatory water bird species, a site is considered important if it has on a
regular basis greater than or equal to one per cent of bio-geographical population. Five
wetlands - Kattampally, Kasaragode, Kumbala-Shiriya, Purathur and Muzhappilangad
- fall in this category.
The census has found Brown-headed Gull, Black-headed Gull, Northern Pintail,
Garganey, Pallas' Gull, Yellow-legged Gull, Lesser Whistling Teal, Lesser Sand Plover,
Cattle Egret, Little Cormorant, Pond Heron, Little Egret, Purple Moorhen and Median
Egret as the most numerous species of the wetlands in the region. As many as 25
species have been found in numbers ranging from 100 to 1,000. Kattampally in Kannur
Wetlands of Kerala
!
tops the list of 11 important sites with high number of birds and high species diversity
followed by Purathur estuary. While Kattampally has 18,622 birds belonging to 51
species, Purathur estuary has 10,411 belonging to 43 species.
Fig. 2.18 : Wetland Birds
A good number of insects are seen associated with the wetlands. Some species of
butterflies, like the Peacock Pansy and Grey Pansy are found abundantly along with
waterbodies because their larval host plants grow profusely close to the water.
However, the insect diversity of Kerala wetlands was not well studied. The wetland
study by CED (2003a) attempted the collection and identification of insects of the
wetlands. The short term study identified 104 species of insects, mainly butterflies.
The major families represented are Nymphalidae (35 species), Papilionidae (15 species),
Pieridae (14 species), Satyridae (9 species) and Lycaenidae (9 species).
The reptilian fauna of the wetlands include the crocodiles, fresh water snakes and
turtles. Out of these, estuarine crocodile (Crocodylus porosus) has been ruthlessly
hunted down to near extinction and only a few remain in isolated areas. The Indian
Flying Fox (Pteropus giganteus), Painted Bat (Kerivoula picta), Three striped Palm
Squirrel (Funambulus palmarum), House Rat (Rattus rattus), Bandicoot rat (Bandicota
sp.) were recorded from the wetland areas.
However, a comprehensive account on the present status of the biodiversity of the
wetlands in Kerala is still lacking.
!
Wetlands of Kerala
2.2.4 Impacts on Population, Economy, Ecosystem
2.2.4.1 Diminution of bioresources
Many developmental activities like construction of huge buildings , roads, railways and
other infrastructure and town ship development has largely destroyed our biodiversity in
the wetland areas . Destructive fishing such as dynamiting, poisoning, wanton destruction
of spawners, habitat alternation for hydroelectric projects, etc., construction of barrages,
bunds, anicuts, dams, etc., also result in impairment of natural habitats of some of these
species.
The effects of industrial pollution are clearly seen in the form of depletion of biota,
especially benthic organisms, fish mortality and presence of high ammonia in water.
The large doses of heavy metals in the estuarine waters are biologically non-degradable
and remain in the food chain of plants and animals. The destructive process leads to
considerable reduction in the density of bivalves/gastropods and isopods in the
backwaters with time. Weed menace leads to blockage of recreational and
communication facilities in a wetland. Dead plants settle to the bottom resulting in
shoaling of the water body. As a result of biodegradation of plant debris, anoxic
conditions develop, which is deleterious to aquatic life. Only those fish species, which
can withstand below par water quality conditions, can survive and commercially
important fishes disappear. Fish population is alarmingly reduced in coconut husk
retting areas (Bijoy, 2004). The fisheries sector is facing pressure from excess fishing
fleet, habitat degradation, over fishing and juvenile fishery. Overexploitation had led
to massive changes in the species composition of the catch and the disappearance of
previously important species.
Consequent on the reduction in the expanse of backwaters, most of the 45000
active fisherman using 38000 fishing artisanals (28000 are unauthorized) are now
concentrating their fishing effort in the remaining open backwaters for their livelihood.
Fish production per ha in the water south of Thanneermukkom bund was found to be
only 7 per cent of that available per hectare from the open backwater. This has
reflected in the socio-economic condition of the rural fishfolks.
2.2.4.2. Species loss
Aquatic ecosystems and wetlands are usually looked down upon as wastelands
and are being reclaimed for various developmental needs, bringing several taxa, which
would be of great potential value in medicine and other industrial uses, are on the
verge of extinction. The encroachment, mining and reclamation in many locations
lead to loss of biodiversity as well as make changes in the ecosystem functioning.
Loss of wild species including endemic species is a phenomenon associated with
ecosystem changes. In the backwaters, the stake net method of fishing removes a
wide array of non-target organisms, which are functionally important to the aquatic
environment. Other destructive type of fishing and pollution has also impact on the
ecology. Excessive weed growth and algal blooms caused by eutrophication also
causes ecosystem changes. The cumulative deposition of macrophytic biomass in
bringing out a gradual alteration in the estuarine benthic communities due to the
Wetlands of Kerala
!!
disturbance in the food chain. The plastic wastes dumped into the system cause blockage,
water stagnation and related problems in the system leading to biodiversity loss.
Mangroves are the most affected ones through out the coastal reaches of Kerala from
south to north. There were reports from Kerala about the occurrence of mangrove species
like Bruguiera eriopetala, B. malabarica, B. parviflora and Ceriops tagal in the past. (Drury,
1864; Hooker, 1879-1885; Gamble, 1919; Rama Rao, 1914; Chand Basha, 1992). But the
recent investigation by Anupama and Sivadasan (2004) could not able trace these species
in Kerala. Destruction of the mangrove habitat has wiped out several species including
salt-water crocodile (Crocodylus porosus) from Kerala.
The loss of biodiversity especially the loss of mangroves has indirectly affected the fish
diversity as well as avifaunal diversity especially the migratory fauna. This was evident in
many of the studies conducted in the State recently. The construction of the
Thanneermukkom barrier and the subsequent obstruction of the migratory pathways is
said to be one of the major reasons for the disappearance of the largest fresh water
prawn, Macrobrachium from the Vembanad backwaters. The entire wetland system
in Kerala has turned to be an endangered one due to shrinkage, pollution and over
exploitation. Specialized gears were operated by the fishermen to capture
Elasmobranches till about 60 years ago. Regular mass migrant species like Teals from
Siberia has considerably reduced in their numbers.
However, a comprehensive study on the species disappeared from the wetlands of
Kerala is lacking.
2.2.4.3. Food toxicity
Certain micro-organisms are capable of converting inorganic mercury into more
toxic mono-methyl and di-methyl mercury. Mono-methyl mercury, the most toxic
mercury compound, is not tightly bound to the sediments and hence could be rapidly
assimilated by living organisms. The Kochi estuary also receives effluents containing
mercury from Chlor-alkali plants and therefore needs caution. There are instances
related to food toxicity in many areas of the estuaries on consumption of fishes.
Cadmium is also a highly toxic metal, which is responsible for the Itai Itai disease.
The aromatic hydrocarbons like benzene, toluene, etc., associated with oils and
lubricants are acute poisons to the aquatic organisms. It is found that hydrocarbons
subjected to bioaccumulation in an organism are stable regardless of their structure
and remain in the food chain without alteration. Chemosensory disruption, anesthesia,
narcosis, cell damage, etc., are some of the effects of oils on organisms.
2.2.4.4. Waterborne and zoonotic diseases
The untreated sewage contains organic and inorganic pollutants and pathogenic
micro-organisms of various water-borne diseases like typhoid, cholera and dysentery.
There are numerous latrines along the banks of the estuary, mostly of single leach-pit type,
causing direct feacal contamination. Water borne diseases, gastro-enteritis in particular, is
!"
Wetlands of Kerala
widespread in most habitations of wetland region, which becomes acute during monsoon
months. The domestic sewages that contain oxygen-demanding wastes, infecting wastes,
infectious agents, organic chemicals and inorganic minerals, affect the water quality of
wetland system.
The changes in landscape - blockage of wetlands, waste accumulation in the wetland
areas are reasons for the resent emergence of many zoonotic diseases in the State.
2.2.4.5 Obstruction to navigation
The encroachment, mining and reclamation has also lead to the decrease in the
depth of water courses in many stretches which has badly affected the water transport
in many places Excessive weed growth due to eutrophication leads to high rate of
siltation resulting in shallowing of a wetland. Growth of rooted weeds in shallow
water results in the shrinkage of water spread area and ultimately transforms it to dry
earth. It is a common sight and experience in backwaters that during rainy season,
'rafts of water hyacinth' float in water and obstruct navigation. Even though, the
problems created by water hyacinth are many, it is to be noted that they have the
ability to absorb toxic substances (especially heavy metals) from the water body.
The clogging of the water channels due to the siltation and sedimentation of many
stretches of wetlands in the State and lake area has been preventing the smooth functioning
Fig. 2.19 : Blocked water way
of water transport system. The reduction in water transport system has led to increased
pressure on the road transport especially in the Kuttanad and its adjacent areas which has
been exerting much pressure on the environment.
2.2.4.6. Decrease in agriculture production and productivity
Agricultural land has considerably reduced during the last three decades mainly because
of the conversion and reclamation of the low lands and other wetland areas for construction
and other purposes. This has also amount to reduction in food production. The productivity
of agricultural land is also reduced due to erosion and loss of soil fertility due to pollution.
The reduction in agriculture has automatically affected the economic condition of the people
Wetlands of Kerala
!#
of the area, especially, the farmers and farm workers. The Kuttanad, Kole, Pokkali and
Kaipad areas are the most affected ones due to this.
2.2.4.7. Scarcity of potable water
Potable water scarcity especially during the summer months is a major issue in many
parts of Kerala. Major reasons for this are pollution and subsequent eutrophication in wetland
areas and salinity intrusion. The excessive growth of weeds as a result of eutrophication
has created the situation of utilization of excess quantity of dissolved oxygen in the water.
This has affected the water quality very badly in many places. Reduction in the ground
water recharge and depletion of ground water resources is one of the major impacts of
wetland conversion and reclamation. The extent of ground water pollution is also very high
in most of the wetland areas, because of the release of the toxic chemicals from the
industries, urban solid wastes, hospital and slaughter house wastes, etc., are the main
causes.
2.2.4.8. Flood and drought
The reclamation and conversion in many places has been leading to excess flooding
of the area during monsoon. Weeds impede run off causing anoxic conditions in the
wetland. Choking of main drainage channels has augmented siltation, thereby affecting
drainage capacity of channels. As a result, flash floods are common in low-lying areas
even during very early phases of monsoon. On the other hand, the uncontrolled water
runoff and reduced ground water recharging is leading to severe drought conditions in
the summer season.
2.2.4.9. Aesthetic value depletion
Due to encroachment, reclamation and waste dumping activities, the aesthetic
value of many wetland regions are highly affected. Vellayani kayal of
Thiruvananthapuram is a good examplefor this. The eutrophication and pollution
problems in the wetlands of Kerala also have much aesthetic impacts, especially
affecting the tourism sector.
2.2.5
RESPONSES
2.2.5.1. Legal and institutional review upon ratification of the
Ramsar Convention
·
At the level of the Executive, the Ministry of Environment and Forests has
constituted a National Committee on Wetlands, Mangroves and Coral reefs which has
representatives from departments and agencies, non-governmental sector, academic
institutions, etc. The Committee meets at least twice a year to review wetland related
activities. Recently this committee was divided into two distinct committees- the Wetlands/
!$
Wetlands of Kerala
Box 2.7: Vellayani Kayal: The shrinking economy and vanishing beauty
Vellayani Kayal, (N.Lat 80 24' 90"- 80 26' 30" and E.Long 76o 59' 68"- 76o 59' 47") is one of
the largest fresh water kayal in the State and the only one of its kind in Thiruvananthapuram District.
The kayal basin falls in Venganoor, Pallichal and Kalliyoor grama panchayats and Thiruvallom and
Nemom divisions of Thiruvananthapuram Corporation and is approximately 11.0 km south of
Thiruvananthapuram City center. The campus of College of Agriculture, Kerala Agricultural University
(KAU) housed in the Koyikkal Kottaram of Travancore royal family, falls on the western side.
Though kayal had a water spread of area of over 750 ha in 1926, it had shrunk to 650 ha in
1972. Since then, it had alarmingly shrunk further in area and now covers hardly 400 ha. In a 1994
map, lake measures a length of 3.7 km and a maximum width of 2.1 km. Though bathy-data suggest
a maximum depth of 3.0 m, evidences exist for having a greater depth. The drinking water needs of
a population living in about 4-5 km radius of the lake are now fully met by this kayal.
As the catchment of the Kayal stands at an average elevation of 29.0 m, the surface run off
(through some thing like 64 streams) and underground recharge into it helps to maintain a large
reservoir of fresh water even through the summer season. The chief outlet, the man made Kannukalichal
(length=2.50 km and width=13.0 m) delivers the surplus waters to the Karamana river to the north
through a regulator with sluice gates and pumps. The floor of this canal is " nearly at the same
elevation" of the adjacent cultivated fields. Further, canal is largely silted up partly due to erosion of
the bunds and partly from accumulation after death of luxuriant aquatic weeds and rooted reed grass
that line the canal shores, making smooth flow of water difficult.
Even though the original extent of Kayal comprised land north of reservoir bund, the same is now
dewatered and used for cultivation. The KAU, by dewatering parts adjacent to Kayal shore, used to
cultivate punja paddy, but this was done away with from 1992 onwards. Since 1992, cultivation is
confined only in the northern part of reservoir bund Pandarakari, Punjakari, Nilamelkari, Mankilikari
and Kanjirathady are the sectors which are not actively cultivated.
The aesthetic beauty of the kayal and its shores as an interface of natural landscape and waterscape
is now lost for ever. The major reasons for this are:
i)
Four roads embankments, allowing poor or inadequate cross flow of water, built across the
kayal segmented it into five distinct sectors. .
ii)
Past and present land owners with shore front went on reclaiming the kayal to aggregate
more land. Such encroachments continue even to day, but on a lower scale, and protect
their booty with gated compounds.
iii)
"Visionless" activities like creation of a reservoir of 32 ha in the kayal by KAU, dewatering
for punja crop, kayal reclamation activities and coconut farming in the paddy field are some
of the reasons for shrinkage of the lake and loss of its aesthetic beauty.
iv)
The recent illegal sand mining from the lake basin creates problems of water quality and
consequent stress on the ecosystem
v)
Once known as the rice bowl of South Kerala, the Vellayani farmlands are nearly devoid of
rice paddy farming. The beauty of the farm lands is lost in many areas created a devaluation
of original aesthetic value.
Wetlands of Kerala
!%
Lakes Committee and the Mangroves and Coral Reefs Committee. Further State level
committees have been appointed that look into the conservation and wise use of the listed
wetland sites in their States.
•
The Ministry of Environment and Forests, Government of India, has also formulated
a National Lake Conservation Plan (NLCP). Vembanad Backwater from Kerala was
identified as one of the sites under NLCP. The main objectives under the programme
would include the following:
•
prevention of pollution from point and non-point sources,
•
catchment area treatment,
•
desilting and weed control,
•
research and development studies on floral and faunal activities and related
ecological aspects and
•
other activities depending on the lake specific conditions such as integrated
development approach, including interface with human populations.
•
The National Environment Policy (NEP) 2006 prepared by the Ministry of
Environment and Forests, outlines a significant number of new and continuing
initiatives for enhancing environmental conservation. These require the
coordinated actions of diverse actors, for the major part organized and
stimulated by one or more public agencies.
The following actions will be taken as part of the NEP2006
(i)
Set up a legally enforceable regulatory mechanism for identified valuable
wetlands, to prevent their degradation and enhance their conservation. Develop
a national inventory of such wetlands.
(ii)
Formulate conservation and prudent use strategies for each significant
catalogued wetland, with participation of local communities, and other relevant
stakeholders.
(iii)
Formulate and implement eco-tourism strategies for identified wetlands through
multistakeholder partnerships involving public agencies, local communities,
and investors.
(iv)
Take explicit account of impacts on wetlands of significant development
projects during the environmental appraisal of such projects; in particular, the
reduction in economic value of wetland environmental services should be
explicitly factored into cost-benefit analysis.
(v)
Consider particular unique wetlands as entities with Incomparable Values,
!&
Wetlands of Kerala
in developing strategies for their protection.
(vi)
Integrate wetland conservation, including conservation of village ponds and tanks,
into sectoral development plans for poverty alleviation and livelihood improvement,
and link efforts for conservation and sustainable use of wetlands with ongoing
rural infrastructure development and employment generation programmes. Promote
traditional techniques and practices for conserving village ponds.
•
The Law Commission in its 186th report has inter-alia recommended establishment
of Environment Courts in each State, consisting of judicial and scientific experts
in the field of environment for dealing with environmental disputes besides having
appellate jurisdiction in respect of appeals under the various Pollution Control Laws.
The commission has also recommended repeal of the National Environment Tribunal
Act, 1995 and the National Environment Appellate Authority Act, 1997. After
examining the Report and discussing the modalities in several consultation meetings
held by Secretary (E&F) with senior officers of the Ministry and the representatives
of the Ministry of Law & Justice, the Ministry has decided to implement the
recommendations of the Law Commission with some modifications. The Ministry
is in the process of preparing draft legislation for the purpose in consultation with
the Ministry of Law and Justice.
2.2.5.2 Research and Development Initiatives
A good number of management programmes were initiated during the last five
years, for developing and implementing sustainable management plans for wetlands.
CWRDM has initiated Management Action Plan (MAP) preparation for Vembanad,
Ashtamudi, Sasthamkotta and Kottuli wetlands with support of MoEF. The MAP is
now started implementing in Kottuli wetlands of Kozhikode.
The studies on the waterfowl of the State got an impetus after the inception of the
Asian Waterfowl Census (AWC) in 1987. The Vembanad Kole Wetlands were practically
unknown to the birdwatchers before the inception of Asian Waterfowl Census.
Presently, 32 wetlands of Kerala are being monitored as part of the Asian Waterfowl
Census, which is an International Waterbird monitoring programme done under the
auspicious Wetlands International.
In Kadalundi the Kerala Forest Department is implementing the MAP prepared by
CED (2003a). CED has successfully completed two Mangrove afforestation projects,
one in Kumarakom, Kottayam (CED, 1999) and other in Kalliasseri, Kannur (CED,
2003b).
2.2.5.3 People's Movements
There are many community based organization in the State engaged in activities
Wetlands of Kerala
!'
Fig. 2.20: Mangrove afforestation, Kalliasseri, Kannur
related to conservation of landscapes and natural resources. Protection groups
("Samrakshana Samithi') are functioning in almost all areas of individual lakes, rivers
and even large ponds. The activities of these groups to some extent are helping in
conservation of these areas. To list some of them are:
i)
Kerala Sastra Sahitya Parishad (KSSP)
ii)
Thanal Conservation Action and Information Network
iii)
Society for Environmental Education in Kerala (SEEK)
iv)
Group Endeavour for Environment and Natural Sustenance (GREENS)
v)
The Vellayani Jagratha Samithi
vi)
Association for Environment Protection, Aluva
vii) Kerala Nadi Samrakshana Samithi
viii) Mangalavanam Paristithi Samrakshana Samithi
ix)
Periyar Samrakshana Samiti
x)
Pampa Parirakshana Samithi
xi)
Chalakudy Puzha Samrakshana Samiti
A good number of writ petitions were filed in the courts by these action groups
against reclamation of wetland areas and for preventing wetland pollution.
"
Wetlands of Kerala
2.3 Status of Environment of Selected Wetlands
In this section status of environment of five selected wetlands in Kerala are described.
Out of these, three wetlands, viz., Vembanad - Kol wetland, Ashtamudi wetland and
Sasthamkotta Lake are listed as Ramsar Sites. The Periyar Lake is in the Periyar Tiger
Reserve, one of the major Protected Area in the State and Kadalundi Estuary, which
holds one of the best Mangrove area (now selected under national conservation plan)
are the other two wetlands described here.
2.3.1. Vembanad - Kol Wetland (Vkw)
2.3.1.1 Introduction
2.3.1.1.1. Location and area
Vembanad - Kol - Wetland System, one of the three Ramsar sites in Kerala
(November 2002), is the largest estuarine system of the western coastal wetland
systems (090 00 100 40 N Latitude and 760 00 -770 30 E Longitude), and is
spread over the districts of Alappuzha, Kottayam, Ernakulam and Thrissur, Kerala.
The VKW is a complex aquatic system of 96 km. long coastal backwaters, lagoons,
marshes, mangroves and reclaimed lands, with intricate networks of natural channels
and man-made canals extending from Kuttanad in the south to the Kol lands of Thrissur
in the north. The total area of the wetland system is 1521.5 sq. km.,- approximately
4% of the States geographic area. The wetland is mostly waterlogged with depths
ranging from 0.6 m to 2.2m and is typically divided into two distinct segments - the
freshwater dominant southern zone and the saltwater dominant northern zone.
2.3.1.1.2 Physical features
Based on physiography, Kerala is divisible into three near-parallel and north-south
trending tracts, viz., the highland (>75.0 amsl), the mid land (7.5 m 75.0 amsl) and
the lowland (<7.5 m amsl). Geologically, the highland is typically underlain by crystalline
rocks of Pre-cambrian age, where as coastal land and parts lowermidland are covered
by sedimentary rocks of Tertiary age. A ubiquitous laterite capping occurs over
crystalline rock basement of midland and the Tertiary sedimentaries. Recent and subrecent sediments occur in low-lying areas and river valleys. VKW is fed by 10 rivers,
all originating in the Western Ghats, flowing westwards through the wetland system
to join the Lakshadweep / Arabian Sea. The area enjoys the full benefit of the southwest
monsoon. The estuarine zone and organics rich sedimentary substratum of the inshore
region makes it a highly preferred and desirable habitat for shrimps breeding. Vembanad
is renowned for its live clam resources and sub-fossil deposits.
2.3.1.1.3 Hydrology
The entire VKW receives drainage from ten rivers, Keecheri in the north to Achankovil
Wetlands of Kerala
"
Fig. 2.21 : Vembanad wetland - Kumarakom area and its Environs (CED, 2003a)
"
Wetlands of Kerala
Fig. 2.22: Vembanad Wetland north of Kuttand upto Puthuvypin (CED, 2003a)
Wetlands of Kerala
"!
in the south, adding up to a total drainage area of 15,770 sq km (40% of the area of
the State), and an annual surface runoff of 21,900 Mm3 (almost 30% of the total
surface water resource of the State). Physiographic peculiarities have always been
the major constraint that adversely affected the utilization of water resources in the
region. Total annual utilizable yield of the ten rivers draining into the wetland system
is estimated to be 12582 Mm3. In Keecheri-Puzhakkal, Karuvannur, Chalakudy,
Muvattupuzha and Meenachil rivers, the total requirement for various purposes
considerably exceeds the utilizable yield, and therefore, the scenario underscores the
need for better management strategies.
The total storage for irrigation and power generation, in the bsins of rivers draining
into the VKW, is of the order of about 6000 Mm3, which is nearly half of the average
flood flow to the wetlands. So, the reservoirs help in containing the floods to the
wetlands to a larger extent (Indo-Dutch Mission, 1989). In general, reservoirs often
act as sediment and nutrient traps. The major interventions in the river basins of this
wetland system are irrigation and hydroelectric projects, besides the network of roads
and a number of bridges. There are three irrigation projects in operation and five
others nearing completion. The total irrigation potential is estimated to be 100200 ha
with a total storage capacity of around 1345 Mm3. Nine of the Kerala's hydroelectric
projects are built in this area, with an installed capacity of 1400 MW.
Muhammed and Nambudripad (1999) of CWRDM successfully applied the Hydraulic
Research Station (Wallingford, UK) model for long-term salinity prediction for Vembanad
wetland, which can also be used for the study of optimum operation of the
Thanneermukkom barrier and the Thottappally spillway and for analyzing the impact
of future interventions and water withdrawals from the river basins and the estuary.
The Thanneermukkom barrier, (at least 1250 m long) was constructed in a narrower
part of the Vembanad Lake, in order to prevent the ingress of salinity into the polders
of Kuttanad during summer season and also to retain the fresh water inflow from the
rivers into the lake. Only two-thirds of the original number of gates is opened in July
to release flood flow, but the gates are closed mid-November. The structure has been
relatively successful in keeping the water in the Kuttanad free of salinity and adding
another crop in dry season. Drawback of the structure has been the loss of opportunity
for marine fish and prawns to migrate upstream, an increase in weed growth in the
upstream and finally, severely restricted the natural flushing of pollutants too.
The usually flooded areas of the Thrissur Kol also suffered from salinity intrusion
through the inlets at Chetwai and Kottappuram. Enammakkal barrage was constructed
about five decades ago, to prevent salinity intrusion into the Kol lands from Chetwai.
Regulator at Enammakkal and the minor one at Kottenkottuvalavu in the lower reach
of the Karuvannur river act both as spillway for the flood waters from the Kol land and
""
Wetlands of Kerala
as a regulator of salt water entry. As the capacity is, somewhat less, a new proposal
is on the way.
A sample of tidal data at Thirunallur (36 km from mouth) shows semi diurnal
character and several kinds of cyclicities and harmonics. Tidal range attenuates rapidly
from the mouth, up to about 15kms, but near the Manappuram bottleneck, very high
tidal ranges of 110 and 133cm have been attained in certain summer months. As
expected, the range is lower during heavy monsoon flow.
During the monsoon, flow propels towards the sea during the entire tidal cycle,
except very close to the mouth. With decrease in river discharge, flow reversal occurs.
Velocity variations are quite pronounced during a tidal cycle, while depth-wise changes
are relatively small.The flushing time, is time required to replace the existing freshwater
in the estuary at a rate equal to the river discharge. By applying the modified tidal
prism method to the Kochi estuary, the flushing time was found to be of the order of
16 - 21 days during summer.
2.3.1.1.4 Biodiversity
Though wetland system is extensively rich in biodiversity, there hasn't been any
comprehensive study on its flora and fauna. Table 2.10 is a summary of available
data.
Table 2.10: Biodiversity of Vembanad Kol Wetland
Groups
No. of species
Flora
Phytoplanktons
67
Herbs, shrubs, Climbers
308
Trees
26
Fauna
Zooplanktons
32
Fishes
102
Insects
26
Birds
189
In a study of Vembanad lake, Bijoy and Unnithan (2004) recorded 24 species of
green algae, 10 species of blue green algae, one species of yellow brown algae, 13
species of desmids and 19 species of diatoms from the Vembanad lake. The Indo Dutch Mission study (1989) listed the aquatic plants of the area. The major aquatic
plants of the area include: Eichhornia crassipes, Salvania molestsa, Nymphaea stellata,
N. nouchali, Nymphoides Hydrophylla, N. indica, Hydrilla verticellata, Najas indica,
Wetlands of Kerala
"#
Limnophila heterophylla, Aponogeton natans, Potamogeton pectinatus, Cyperus
corymbosus, Ischaemum barbatum etc. The study conducted by Sabu & Babu 2007
recorded 8 pteridophytes and 326 Angiosperms of which only 26 are trees.The floristic
diversity of the area includes 13 Mangroves and more than 30 Mangrove associates,
present in the area, of which the true mangrove, Exoecaria agallocha and Bruguiera
sexangula are considered as rare species.
The wetlands support diverse fauna, including a large variety of fish, prawns and
clams, reptiles and birds and provide a habitat for both anadromous and catadromous
fish species. Almost all the 20 groups of Zooplanktons recorded from Kerla backwaters
are present in VKW.
The growth and distribution of fish in the backwaters are greatly affected by the
salinity range of the water. With the onset of southwest monsoon, in the estuary,
salinity declines rapidly to almost that of fresh water, resulting in a decline of a
number of estuarine fish species. From September onwards, the brackish water habitat
gradually re-emerges in the backwater and marine fish, tolerant to a wide salinity
ranges, appear in the lower reaches of the estuary. During the pre-monsoon period,
the physico-chemical conditions at the mouth and lower reaches of the estuary are
very similar to those of the adjacent sea. Coastal marine fish, tolerant to wide salinity
fluctuations, migrate over long distances into the estuary. The fish fauna identified
from the whole area comes to 102 species, mainly of mullets. Molluscs include the
black clam (Velorita cyprinoids; V. cornucopia), Mertrix meretrix, M. costa and Ostria
calculata. The mussels, Perna viridis and P. indica and the brackish water oyster,
Crassostrea madrasensis, occur abundantly in the backwaters and river mouths. The
soft-organic matter rich - sediment-substrata of the in-shore region are an ideal habitat
for shrimps. Estuarine zone plays an important role in the life cycle of many shrimps
caught and the entire Vembanad-Kol, acts as nursery for important shrimps like Penaeus
indicus, P. monodon, Metapenaeus dobsoni, M.monoceros, M. affinis, Macrobrachium
rosenbergii. Marine prawns, belonging to the family Penaeidae, are exploited both in
the marine and estuarine waters. They spawn in the sea and the larvae migrate to the
estuary to feed on the nutrient-rich environment. Among other Penaeids are Penaeus
indicus, Metapenaeus monodon and M. dobsoni. The fresh water prawns of Kochi
backwaters include Macrobrachium rosenbergii and M. idea. These fresh water prawns
live in both fresh and brackish waters. The crustaceans include the edible crab Scylla
serrata also.
The avifauna of this area requires special mention. During the winter months, the
Vembanad supports the third largest population of more than 20,000 waterfowls in
India. The birds come from different region and stay here for breeding and feeding.
Kol lands provide a congenial habitat for a wide variety of birds including the waterfowls.
"$
Wetlands of Kerala
In Mangalavanam, primarily a bird refuge, 149 birds were identified of which 50 were
migratory.
The area is also rich in insect biodiversity. CED study identified 26 species of
insects from the area. Majority of them are butterflies belonging to the order Lepidoptera.
2.3.1.1.5 Inland navigation
The waterways formed by backwater, estuaries, lagoons and canals, spread over
196 km in the north-south and 29 km in the east-west directions, play an important
role in the transportation system of the Vembanad region and practically, almost all
the villages can be accessed through water transport. Muvattupuzha, Meenachil,
Pamba and Achencoil rivers, draining into the lagoon, are navigable upto distances of
about 30 km upstream in the tidal reach. The Kottappuram-Chetwai waterway supports
the inland navigation through the heart of Kol lands. A survey in 1986, revealed that
out of a total of 14.74 million tons of cargo, of which inland waterways handled 1.74
million tons (11.84%). The Government of India has declared the Kollam-Kottappuram
segment of west-coast canal system, passing though the Vembanad-Kol system,
covering a distance of 209 km, as a National Waterway
2.3.1.1.6 Tourism
The VKW with its extensive network of rivers, lakes, canals, and lagoons fringed
by lush green coconut groves and paddy fields, harbouring a variety of birds, is one of
the most attractive backwater systems in the world. There are many historic places
situated on the shores and hinterlands of the Vembanad-Kol backwaters. The offset
of SW monsoon, is marked by scheduling of spectacular rowing competition involving
several magnificient and large wooden canoes in the backwaters, which obviously
attract thousands of spectators including foreign tourists. Further, the VKW is a treasure
trove for ornithologists and bird lovers because of its rich avifauna. Tourism industry
in this belt is now flourishing well especially in Kumarakam, Alappuzha and Kochi, of
which Kumarakam has the top tourism potential. As a result, many new tourism
facilities (like resorts and hotels) are coming up without any care or concern to the
natural system or culture or heritage of the area.
2.3.1.2 Major management issues
2.3.1.2.1 Driving forces
All the nine driving forces (cited in ch.II), viz. i) population growth and urbanization,
ii) industrial development, iii) infrastructure development, iv) agriculture, v) aquaculture,
vi) fisheries, vii) deforestation, viii) services, ix) households, x) water transport and xi)
tourism, do exist in the Vembanad kol wetland system.
Wetlands of Kerala
"%
Among all wetlands of Kerala, Vembanad is the most affected one as a result of
urbanization and population growth, industrial development, agriculture and aquaculture,
services, water transport, tourism etc. An analysis of population data reveals that
population density of this area now stands at 3000 (Census, 2001), a fairly steep rise
from 2400 (Census, 1991). Areas like Kumarakam, Njarakkal, Vypin, etc., are swiftly
urbanizing. These areas and the urban centres like Kochi, Alappuzha, Cherthala, N.
Paravur, etc., are expanding at the expense of Vembanad wetlands.
Deforestation is rampant in all the 10 drainage basins leading into the wetland.
Interventions in the system for meeting the basic needs like water, electricity etc is
relatively high. There are 778 (32 urban and 746 rural) water supply projects in the
five districts (viz., Kottayam, Alappuzha, Ernakulam, Idukki and Thrissur) and most of
them are using the water from one or other of the 10 drainage basins. Release of
domestic waste into the system and defecation in the open has become common
place among the people settled along the shores. For several island communities in
the Vembanad, the waterscape acts also as "highway" for the movement of personnel
and goods and services.
2.3.1.2.2 Pressures
The unplanned development and economic activities for supporting the needs of
increasing population continues to exerted ever growing pressure on the ecosystem.
The types of major pressures identified are same as in the list in section II
The Vembanad estuary receives effluents from chemical and engineering industries,
food and drug manufacturing industries and also from paper, rayon, rubber, textiles
and plywood industries. It is estimated that nearly 260 mld of such industrial effluents
reach the estuary from the industrial belt of Greater Kochi. In addition, the Cochin
shipyard and port are releasing sizable quantities of waste oil, paints, metal and paint
scrapings. The traditional retting practice in coir sector of this area also exerts pressure
on the system.
The annual fertilizer consumption in Kuttanad alone is estimated as 20000 tons
(CWRDM). Agriculture and aquaculture practices prevalent in the drainage basins are
also partly responsible for eutrophication through deposition of eroded top soil and
agrochemicals and pesticides.
Kochi city alone generates 2550 mld of urban sewage that enters the Vembanad
directly. Slaughter house wastes from the markets and hospital wastes also reach the
system through the extensive network of canals in Kochi and through the rivers.
Construction and industrial sectors here depend on wetlands for mined materials
fuelling an extensive mining operation - a brisk business.
"&
Wetlands of Kerala
Present status of this land-water system is the result of a series of massive human
interventions and consequences. The hydraulic/hydrologic interventions within the
entire wetland system also exerted pressure in the sustainability of wetlands. The
first and the oldest were the reclamation and creation of the Wellington Island and the
Shipping channel maintained in the Cochin harbour. Then came the major reclamation
and bunding works in the Kuttanad area for improving agricultural output in the area.
The third intervention was the construction of the Thottapally Spillway (1955) to
divert floodwaters of Achankovil, Pamba, Manimala and Meenachil directly to the
sea. The last intervention was the Thanneermukkom barrier (1975) built to prevent
salinity ingress into the farmland of Kuttanad in summer. All the above interventions,
except the first significantly altered the original flow pattern, salinity ingress, pollution
dispersion and other characteristics. The Pathalam bund, a temporary barrage, is
constructed each year on the Eloor branch of Periyar River since 1981, to prevent
salinity ingress from Vembanad backwater and contamination of the water supply to
the industrial units (rare earths, fertilizers, insecticides, catalysts and chemicals). But
the enormous quantities of wastewater (about 8000 m3) discharged daily into this
branch are not flushed out, leading to stagnation and buildup of pollution to toxic
levels
Fig. 2.23: Thottapally Spillway
Authorised and unauthorized sand mining is common in all areas of Vembanad
wetland system. The uncontrolled mining of shells from the lake is also posing a
threat to the eco system. Dredging of the sub-fossil lime shell to a depth of 7 m for
industrial purpose is also going on.
Wetlands of Kerala
"'
Fig. 2.24 : Thanneermukkom barrier
2.3.1.2.3. State of Environment
The Vembanad estuary serves as a sink for domestic and urban sewage from
Kochi. In addition, sewage of other municipalities is also directly discharged into the
Vembanad lake without any treatment. Kochi Corporation sewage collection system
empties its wastes containing high particulate organic matter into the estuary through
Padiyathupalam, Kalvathi, Rameswaram, Pulimutty and Thevara canals. 16 major
industries discharge nearly 0.104 mm3 of wastes including organic wastes of the
order of 260 tons per day. The river discharges of 19,000 mm3/year also carry a
fertilizer residue of 20000 tons/year. The Point and Diffuse Sources of pollution is
shown in fig. 2.25.
The effect of domestic sewage on the ecology of the lagoon is significant. Faecal
coliform counts up to 1800/100 ml large quantities of polyphenols along with hydrogen
sulphide are released from the coconut husk retting, ground leading to anoxic conditions.
Hydrobiological conditions of the estuary are greatly influenced by seawater intrusion
and influx of freshwater (Lakshmanan et al, 1982). Organic carbon in the sediments
was higher during monsoon due to the contribution from land run off (Remani, et al,
1980). The study with reference to the indicator bacteria reveals that the principal
source of faecal pollution is of the non-human type originating from land drainage,
sewage and organic discharge (Gore et al 1979). Higher COD (Chemical Oxygen
Demand) values observed are probably due to the domestic sewage and water
discharged into the harbour area (Sarala Devi et al 1979). Studies also showed that
there is appreciable degree of organic pollution in the harbour area (Unnithan et al,
1975).
#
Wetlands of Kerala
The effluents from industries carrying a heavy load of ammonia (432-560 ppm
which is far above the accepted lethal limit of 2-5 ppm) pouring into the system along
with many other pollutants such as acids and suspended solids in varying quantities,
have changed the hydrochemistry conditions to extreme toxic levels, so as to cause
heavy mortality of the animals. Total dissolved solids in water rise as high as 53750
mg/l in summer, which may come down to 16 mg/1 during the rainy season. Water is
found to be highly acidic, loaded with ammonia, fluorides and phosphates, resulting in
massive fish kills. Remani (1979) reported that in some of the polluted waters, BOD
(Biological Oxygen Demand) values reach 513.76-mg/ l, sulphide 4.97 mg/l and oxygen
less than 0.05 ml/l.
Fig. 2.25 : Point and Diffuse Sources of Pollution
It was observed that pollutants like Copper, Zinc, Cadmium, Lead, Nickel and Iron
(dissolved metals) were highest at the effluent discharge point gradually decreases
towards the bar mouth. But it was lowest in the upstream reaches of the Periyar
Wetlands of Kerala
#
River. Seasonal data show that the level of pollutants is higher during the pre-monsoon
season and due to fresh water influx lowest during the monsoon season.
A study on the wetlands of Kerala by CED (2003a) analysed the water quality
parameters of the Vembanad wetland system (table 2.11).
Studies by Rajendran et al (1987) showed that concentration of mercury in the
oyster Crassostrea madrasensis collected from the Cochin estuary showed levels of
mercury, ranging from 15 to 48ppb in a small size oyster and 7.0 to 37.0 ppb in larger
size. The concentration of mercury in the sediment samples ranged from 31 to 144
ppb. A paper mill and other factories engaged in chemical manufacturing release
mercury to the system.
A high level of organic pollution is noticed in the system, especially in Kochi. Large
values of hydrogen sulphide were observed at the points of discharge of organic
waste into the estuary. Lower oxygen values showed higher values of BOD and
hydrogen sulphide. The extent of pollution in these areas is well above the tolerance
level of estuarine fauna. Retting of coconut husk is another major source of organic
pollution in the backwaters of Cochin.
Detention time (hydraulic residence time) of a lake influences the vulnerability to
pollution of the lake too. A larger value for detention time indicates that the lake is
more receptive to pollution. Pollutants from such a lake are removed at a slower rate.
A study by CWRDM determined the residence time of the Vembanad Lake as 114 to
185 days based on the volume of the lake and inflow to the lake.
Phosphorous concentration in the lake over the years is given in fig 2.26 Increase
in the yearly average phosphorous concentration resulted in the favourable conditions
for the plankton production. The higher concentration of phosphate noticed especially
during monsoon and pre-monsoon seasons are probably associated with bottom
turbulence and tidal influences (Padmakumar et al 2002). Balachandran et al (1986)
reported that phosphate and nitrates were present in very low levels up to mid 70s'
from where, due to the combined effect of increased industrial and agricultural activities,
the levels increased during 80s' and 90s'. During 1965, the surface phosphate and
nitrate were 0.75 and 2.0 µM, which has climbed to 2.9 and 6 µM respectively by
2000 even though, between the years it showed still higher levels. The trend of build
up of nitrogen and phosphorus fractions after 1975 and from 1980 onwards, remained
rising. Enrichment of phosphorus with respect to nitrogen is more leading to mesotrophic
waters. The build up for inorganic phosphate since 1973, and the subsequent increase
in waste discharge had ultimately led to extreme levels of ammonia, phosphate and
nitrate in the estuarine region. During 1980-81, nitrate and phosphate levels stood at
40 and 12 µM with upstream peaks at 108 µM and 186µM. Phosphate levels up to
88µM during 1982-83 was reported the northern upstream stations. During 1990,
#
Wetlands of Kerala
Table 2.11: Water quality, Vembanad - kol wetlands (CED 2003a)
Location
Parameters
Kumarakam
(Backwater
near resort)
Kochi
(Mangalavanam)
Thrissur Kol
(Perumpuzha)
Colour
Colourless
Colourless
Colourless
Odour
Nil
Nil
Nil
Depth ( meter)
1.5
1
1
pH (NTU)
5.38
7.70
Turbidity (mg/I)
-
-
25.3
Dissolved Oxygen (mg/I)
4
8.4
2
Hardness (mg/I)
2516
3800
16
Acidity (mg/I)
6
10
30
Alkalinity (mg/l)
2
7.85
40
Salinity (ppt)
23.524
19.539
0.0053
Total Solids (mg/I)
10740
34800
1800
Total Dissolved Solids (mg/I)
7200
29800
800
Total Suspended Solids (mg/I)
3540
5000
1000
Chloride (mg/I as NaCl)
21142
24576
16.43
Sulphide (mg/I)
6.4
0.8
60
Nitrite (mg/I)
-
-
0.095
Phosphate (µg Po4 - P/I)
1.3
2.4
0.0035
Primary Productivity (mg/l/hr)
0.4
-
3.2 (gross)
2.4 (net)
nutrient maximum reported was 98.48 for nitrate and 15.11 µM for phosphate. Sheeba
(2000) reported nutrient enrichment in this system and recorded nitrate up to 451µM
and phosphate up to 33 µM at the bar mouth.
Recently CWRDM modeled eutrophication of the Vembanad Lake, using the Aquatox
Ecological risk assessment model of the US Environmental Protection Agency (Aquatox,
2004). The primary data on water quality of Vembanad Lake was collected during
2003 and 2004 was used. A constant loading data in grams/day were used for the
nutrients based on the available secondary data. The mean monthly inflow values
Wetlands of Kerala
#!
were calculated based on 13 years dataset available. The non-point source pollution
load to the lake was estimated using primary field data.
The lake was simulated using daily mean average value for inflow and annual
average for nutrient loading. The simulation predicts the maximum chlorophyll values
during pre monsoon season. The bottom turbulence and tidal influence also may be
contributing to the higher concentration of phytoplankton biomass during these months.
Fig. 2.26: Concentration of Phosphorous in Vembanad Lake
The results of the study reveal that eutrophication of the Vembanad Lake is mainly
phosphorous related. The lake is infested with growth of phytoplankton especially
during pre monsoon and beginning of monsoon months. In addition to the nutrient
load received by the lake from point sources, the lake is also polluted in the southern,
eastern and western parts by diffuse pollutants such as agricultural and municipal
effluents. The simulation studies of the lake predicted eutrophication of the lake with
high concentration of phytoplankton growth and clarity indicated by lower seechi
depth. The simulation also suggested that, the total phosphorous load to the lake
should be regulated at 12.5 % of the present phosphorous load input to the lake to
transform to oligotrophic type.
Shrinkage of Vembanad Lake to 37% (13224 ha) of its original area (36329 ha), as
a result of land reclamation, has been the most important environmental consequence.
About 23105 ha of land have been reclaimed from the lake during 1834-1984 amounting
to 63% of the lake area. Incentive given by the government after the Second World
War by way of interest-free loans for intensive rice cultivation further encouraged
reclamation activities. During the period from 1941 to 1950, almost all shallow regions
of the lake have been reclaimed by constructing dykes. It is estimated that 21%
reclamation has taken place during the span of last 15 years.
The depth of the Vembanad Lake has been reduced by 40-50% in all zones except
between Aroor and Wellington Island and the Cochin port zone. The water carrying
#"
Wetlands of Kerala
capacity of the system has been reduced to an abysmal 0.6 km3 from 2.4 km3 with
a decline of 78%. The comparative data shows that the average depth of Vembanad
backwater has been reduced from 6.7 m to 4.4 m over the 50 years from 1930's to
1980's (table 2.12).
Erosion, transport and deposition of sediments are natural processes controlled by
mainly geologic, climatic, physical, vegetative and other conditions. However, during
the present century, due to deforestation, manmade structures and change in cropping
pattern in the uplands, rate of release of sediment from watersheds and supply to the
wetlands have grown up, causing environmental problems.
2.3.1.2.4 Impacts on Population, Economy and Ecosystem
The threat posed by activities of most of the stakeholders on the health of Vembanad
ecosystem is severe and dangerous to levels exceeding the carrying capacity of the
system. Studies on the biological processes of Cochin estuary reveals that biodiversity
of Cochin backwater has been on the decline. The VKW had a much greener past
when significantly large portions of the region were covered with a lush growth of
various types of mangrove vegetation (Vannucci, 1987). Extensive Mangrove vegetation
that once existed in this area is now detached with stunted Rhizophora and Sonneratia
with scattered reed beds in areas close to Kumarakom, Kannamali, Mangalavanam,
Kumbalam and Puthuvypin. In the polluted and marginal zones bivalves are lesser in
number. The effects of industrial pollution manifests as depletion of biota, especially
benthic organisms. Density of benthic fauna got reduced as well as fish mortality due
to ammonia content (Unnithan et al., 1975). Saraladevi et al (1991) found that benthic
organisms were totally absent in the polluted areas of Cochin backwater. Jayapalan
(1976) reported deleterious effect of effluents on plankton productivity of Cochin
backwater due to pollution.
Table 2.12 : Depth ranges in various sectors, Vembanad Estuary (Thomson, 2003)
Between Thanneermukkom bund & Vaikom
Depth
range
in 1930s
8-9
Depth
range
in 1980s
3-4
Depth
range
in 2001
3.5 - 4
Between Vaikom & South Paravoor
7-9
4-5
3.5 4.0
Between South Paravoor & Aroor
5-6
3-4
3 - 4.5
Between Aroor & South of Willington Island
7-8
7-8
7-8
Cochin Harbour Region
7-8
7-8
7-8
Between Bolgatti & Cherai
3 - 4.5
2 - 2.5
1.5 - 2
Between Cherai & Munambam
3-6
2.5 - 4
2.5 - 4
Stations
Wetlands of Kerala
##
Influence of sewage and the heavy load of organic matter into the lake are responsible
for the decrease in summer. Unnithan et al, (1977) reported fish mortality (Ambassis
gymnocephalus) due to industrial pollution reported from the upper reaches of Cochin
estuary. Kurian (1972) and Ansari (1977) reported that density of bivalves, gastropods
and isopods in the backwaters have considerably diminished. Fish shoal entering the
polluted zone is unable to tolerate the combined effects of pollution, resulting in the
sudden death due to asphyxiation. Reclamation and bunds in the river channel do
affect the breeding and migration of aquatic species.
Accumulation of sediments in Cochin estuary created serious imbalances on the
eco system functions of backwaters seriously in recent years especially. Sediment
accumulation has reduced the mean depth of estuaries in many sectors affecting
fisheries, water transport and trade.
Sewage borne pathogenic micro-organisms, causing diseases such as Typhoid,
Cholera and Dysentery also affect the fish wealth. Periodic outbreaks of such diseases
are reported from Kuttanad and other areas along the shores of Vembanad Lake in
Alappuzha district. Periodic outbreak of fish disease is also common in Kuttanad
region of Vembanad Lake.
Problems associated with eutrophication of the Vembanad Lake are many. Luxuriant
growth of aquatic plants like Eichornia crassipes, Salvania molesta, Nymphoides spp.,
Aponogeton crispium etc noticed in the lake (Indo Dutch Mission, 1989), hinder the
navigation, create anoxic conditions in the bottom of the lake and choke the main
drainage channels.
Industrial dredging of the sub-fossil lime shell to a depth of 7 m had made the
lagoon bed unsuitable for the growth of black clam.
2.3.1.2.5. Responses
Inclusion of the area in the Ramsar list in 2002 offers huge opportunities for
development and implementation of a scientific management plan for the use of the
Vembanad- Kol wetland system.
Considering the fragile ecosystem of the wetland, deterioration of water quality
and consequent damage to aquatic organisms and the shrinkage of Vembanad Lake,
this wetland system was included in the National Lake Conservation Plan (NLCP) by
the National River Conservation Authority, chaired by the Prime Minister under the
Ministry of Environment and Forest (MoEF) in June 2003. Under the NLCP, projects of
conservation and management of polluted lakes are taken up on 70:30 costs sharing
between the central and state governments as in the case of river action plans.
#$
Wetlands of Kerala
Several NGOs like Kerala River Conservation Council, the Kuttand Foundation etc
are approaching the government for implementing an integrated management-actionplan for this wetland. Recently the GOI entrusted the M.S. Swaminathan Commission
to submit recommendations for revival of agriculture and allied sectors in Kuttanad
region and preserve its ecosystem. The commission is expected to submit a report
with detailed action plan for the sustainable use resources of the area.
2.3.2. Ashtamudi Wetland (AW)
2.3.2.1.1 Location and area
Ashtamudi Wetland (Ashtamudi Kayal, area = 61.4 km2), Ramsar site No. 1204,
is near Kollam City (08°57'N 076°35'E) in Kerala and falls in Kollam City Corporation
and adjoining Grama Panchayats. This extensive estuarine system, the second largest
and deepest in Kerala, is connected to sea and is of extraordinary importance for its
hydrological functions and biodiversity. Like fingers of a palm, it has multiple branches
viz. Ashtamudi Kayal, Kumbalathu Kayal, Kanjirakkottu Kayal, Kandanchira Kayal and
Karipuzha Kayal and opens to the sea through an inlet at Neendakara. The major river
discharging into the AW is Kallada whose chief tributries are Kulathupuzha, Chenduruni,
and Kalthuruthy rivers.
2.3.2.1.2. Physical setting
Seaward portion of the AW is in the lowland, while toward east and south, i.e.,
landward, the hinterland falls in the midland. Geologically, the lake basin and environs
are underlain by the Quaternary and Tertiary sediments and sedimentary rocks, in
that the former is made of marine and fluvial alluvium of recent age, and the latter
consists of Laterite, sandstones and clays of Warkalai formation.
The various landforms noticed are:
•
Coastal plain: This unit consists of sandy plain with alternating ridges and
swales and a narrow modern beach. Mostly utilised for human settlement and
mixed crops.
•
Undulating uplands: These are dissected uplands of 10-20m in height to the
east and south with nearly flat tops and gentle slopes, carved out of tertiary
formations.
•
Valley fills: Broad valleys formed by dissection and erosion of Tertiary
formations, are filled with alluvial materials. Such valleys are intensely cultivated
with paddy.
Wetlands of Kerala
#%
Fig. 2.27: Ashtamudi Wetland and Environs (CED, 2003a)
•
Alluvial plain: Vast alluvial plains of the Kallada River constitute this unit. This
plain consists of several topographic lows, formed of marshes, water logged
areas and palaeochannels.
•
Islets: There are a number of islets or 'Thuruths' in the Ashtamudi Kayal. They
possibly formed by erosion of loose tertiary sediments from parts of hinterland
and deposition in the lake.
#&
Wetlands of Kerala
2.3.2.1.3.
Hydrology
Ashtamudi, the deepest estuary in Kerala, receives discharge of Kallada River (length
= 120 km; Basin Area = 1700 km2 and discharge = 3375 Mm3) basin receiving an
average annual rainfall of 2400 mm. The Ashtamudi wetland also serves the role of
containing the flood waters, which otherwise would have had an adverse impact on
the thickly populated coastal land and parts of the city of Kollam. A major intervention
affecting hydrology of the wetland was the construction of Kallada dam in the upper
catchment, built to irrigate 61630 ha of paddy and upland crops. This 85.3 m high 35
m long (area - 23 km2 @ FRL) straight gravity masonry dam created a large reservoir
of storing 505 Mm3 of water, is the largest irrigation dam and reservoir. The dam
reduced the summer flows significantly, aggravating salinity ingress in the wetland
and into the river.
Ashtamudi wetland ecosystem, a home to a wide variety of flora and fauna (table
2.13.), once had very good mangrove vegetation, but now stands reduced to a very
small patch near the Asramom Park. Around 7 species of true and mangrove associates
occur in this area. The floristic diversity covers around 225 species of herbs, shrubs,
climbers and 31 trees of which about 35% are medicinal plants have been identified
from the area.
Table 2.13: Biodiversity of the Ashtamudi Wetland (Compiled from various sources)
Groups
No. of species
Flora
Phytoplanktons
Herbs, shrubs, climbers
Trees
9
225
31
Fauna
Fishes
97
Insects
45
Birds
57
Zooplanktons
29
Asramom area was once a repository of a variety of plants and its dependant
animal species. The woody trees like Holigharrna arnottiana, Syzigium travencoricum,
S. zeylanicum etc., are still present of which Syzigium travencoricum is an endangered
species (IUCN), Calamus rotang, vulnerable species is also present in this site.
Wetlands of Kerala
#'
Rhizophora apiculata, R. mucronata, Ardesia littoralis and Avicennia marina, once
abundant in this mangrove area, have almost completely degraded.
The wetland supports 57 species of birds (6 migratory and 51 resident species)
and 97 species of fish (42 typically marine, 3 estuarine, 9 estuarine-riverine and 15
marine-estuarine). About 40 species of wetland dependant birds are noted in Ashtamudi
Lake, out of which 45% are long distant migrants. Terns, plovers, cormorants and
herons are most abundant birds.
The CED (2003a) study reported 45 insect species, including 26 species of butterfly,
5 odonates, 9 hymenopterans, and 2 orthopterans, 1 hemipteran and 2 coleopterans.
About 29 zooplankton species have also been identified. From the water body, 9
phytoplanktons such as Amphora, Borosigma, Cyclotella, Cymbella, Gyrozigma,
Meloziva, Navicula and Nitzschi have also been identified.
2.3.2.1.5 Tourism
Ashtamudi Lake promises high potential in tourism industry, especially in areas like
Backwater cruises; hotel facilities along the lake shore, etc. The internationally famous
Ashtamudi Resort known for its ayurvedic treatments and oil massages are situated
right on the shore of Ashtamudi Lake. The Kerala Tourism Development Corporation
(KTDC) operates luxury boat for cruises for domestic as well as international tourists.
Tourism related activities in and around Ashtamudi Lake is already earning sizable
revenue for the State. Due to all such factors, economic potential of the lake is also
very high.
2.3.2.2 Major Management Issues
2.3.2.2.1. Driving forces
All the nine driving forces listed in section II are equally applicable here also. Number
of Paper, Aluminium and ceramic industries are functioning in the basin of Kallada
River. Coconut husk retting is a common pursuit. Public and private sector construction
activities for developing infrastructure are also noticed. Human settlements, traditionally
centered in the hinterland of the backwaters led to the deposition of household wastes
along with feces from hanging latrines. The lake acts as the water-route of transport
and exchange among the island - village - communities and regular boat services are
operating to Chavara south and Perumon in addition to more than 50 native canoes
serving the transport and trade needs.
Fishing is the major activity in the wetland. Aquaculture activities like prawn culture,
mussel culture etc are also common. Legal and illegal sand mining is on the rise in
estuary as well as the river channel. There are 88 (7 urban and 81 rural) water supply
$
Wetlands of Kerala
projects in the district, most of them are sourcing water from the Kallada drainage
basin. Of late, backwater tourism using houseboats is a flourishing industry.
2.3.2.2.2 Pressures
More and more industries including tourism coming up adjacent to the shores and
basin are without effluent and waste treatment facilities. Effluents from the industries
like ceramic, aluminium, paper, match, spinning mills and cashew factories, located in
the drainage basin of Kallada river and the backwater are released into the system.
Small scale industries and other livelihood earning activities like fish processing units,
boat building yards, food processing units, slaughter houses, etc., are also noticed.
The effluents released from such units include fish spoilage and residues, slaughter
house wastes, waste oil, paints, metal and paint scrapings etc. Coconut husk retting
and related operations, though of small scale, are intensive, contributing heavily to
the organic pollution load of the open water bodies. Wastes from the houseboats and
resorts are also ultimately released into the wetland, raising nutrient levels, pathogens
and other organic substances leading to pollution and eutrophication and finally
degradation of the ecosystem. The lack of a well planned waste management
programme for urban as well as rural areas also exerts great pressure on the system.
The fishing boats fitted with outboard engines releases large quality of hydrocarbons
into the system. Legal and illegal encroachment and reclamation of wetlands are on
the rise in many areas for creating infrastructure facilities to the rising urban population.
Such actions cause shrinking of the wetlands and destruction of biodiversity.
The agricultural practices warrant the use of chemical/organic fertilizers and
insecticides/pesticides, and the residues on entering the system cause pollution and
eutrophication. The modern aquaculture also demands the use of many nutrients,
inducing changes in the ecosystem.
Land use changes and deforestation in the watershed as well as the increase in
withdrawal of surface and ground water from the river basin for irrigation, domestic,
industrial and other uses have also put forth pressure on the system through stream
flow changes. Hydrological interventions, like the Kallada Dam also exert pressure on
the system. Natural process like floods, erosion, sedimentation and natural disasters
do exert pressure in the AW. The hydro period of the wetland has changed due to the
seasonal variations in the fresh water inflow into the wetland. Since hydrology is the
single most important factor of the wetland and the hydro-period is the signature of
the wetland, the changes is the hydro-period are sure to bring about changes to the
wetland ecosystem.
Wetlands of Kerala
$
2.3.2.2.3. State of Environment
Ashtamudi Lake serves as source of water and sink for various industries in and
around Kollam District. Retting of coconut husk, discharge of sewage, organic wastes
from fish and seafood processing industries and oil waste from fishing boats etc are
chief polluters of the water body. It is also a sink for excess nutrient loads shed from
agricultural lands. Physical pollution is enhanced by dumping of washings from KSRTC
Bus Depot located along the shore of the Ashtamudi.
Water quality data at selected sites are within permissible limits (table 2.14). Pollution
- indicator - parameters, like values for sulphide, nitrite and phosphate though show
considerable variation, can be attributed to industries located along the banks of the
Ashtamudi Lake, discharging their effluents into the lake. Also slaughter house wastes
too add to the organic content.
It is estimated that the total extent of the wetland underwent shrinking to the tune
of 61.4 sq km.
Table2.14: Water Quality, Ashtamudi wetland (CED, 2003a)
Location
Parameters
Kakkathuruthu
Colour
Colorless
Odour
Nil
Depth ( meter)
3
Perumpe
Vincent
thuruthu
Asramom
Colorless
Colorless
Colorless
Colorless
Nil
Nil
Nil
Nil
2
3.5
3
2
pH (NTU)
7.99
8.0
8.1
7.9
8.2
Turbidity (mg/I)
17.6
17.2
17.4
17.5
19.1
6
6.6
6.4
7
7.5
6020
5620
4280
4940
5280
Hardness (mg/I)
Acidity (mg/I)
Nil
Nil
Nil
Nil
Nil
Alkalinity (mg/l)
76
76
86
64
106
22.9
22.4
17.7
25.59
25.59
Total Solids (mg/I)
20600
27700
25100
12500
24700
20000
26300
22900
10900
22300
600
1400
2200
1600
2500
20972.3
20492.0
16169.5
23373.7
23373.7
Salinity (ppt)
Sulphide (mg/I)
Nitrite (mg/I)
$
Thekkumbhagam
14.4
11.2
11.2
9.6
12.8
0.00125
0.0016
0.0025
0.004
0.004
0.001
0.002
0.003
0.0013
0.0035
_
0.4
_
_
Wetlands of Kerala
2.3.2.2.4
Impacts on population, economy and ecosystem
Natural habitat faces serious degradation caused by reclamation and consequent
shrinkage of the estuary. The mangrove areas in the Asramom are nearly lost.
Reclamation and bunding affect the natural facility for breeding and migration of
species. As a result, impact to the system is the depletion of bioresources and economic
loss. Comparison with past data proves that, the fish diversity as well as its abundance
declined considerably in Ashtamudi Lake, and is attributed to various parameters like
change in physiography, change in climate, unscientific fishing methods, over
exploitation etc. The large population of fishermen living around Ashtamudi is finding
it very difficult to earn a livelihood from the scarcity of fish and poor catches.
Pollution of the system though not severe, compared to the other areas, ground
water pollution in many areas are considerable leading to scarcity of potable water.
Increase in organic content in the soil resulted in heavy weed growth, which is creating
problems to agriculture, fishing, and water transport.
2.3.2.2.5 Responses
After declaration of the area as Ramsar site in 2002, the Ministry of Environment
and Forests initiated action for sustainable management of the area. A Management
Action Plan was prepared by CWRDM and submitted to MoEF in 1999. The MAP aims
at comprehensive development and management of the natural resources associated
with the Ashtamudi Wetland System for its sustainable utilization and conservation.
The major components included in the MAP are, catchment treatment (afforestation
and soil and water conservation), conservation of flora and fauna, pollution control
measures, scientific management of wetland fisheries, social interventions, monitoring
and evaluation. The programmes are expected to be implemented through Departments
and Agencies like, Department of Forests and Wild Life, Department of Fisheries,
State Fisheries Resource Management Society (FIRMA), Soil Conservation Wing of
the Agriculture Department, etc. The MAP was approved by the Ministry of Environment
and Forests (MoEF), Government of India (letter No. J/22012/2/86-W dated
23.03.2000), is being implemented with the support and overall supervision of Kerala
State Council for Science Technology and Environment, Govt. of Kerala.
2.3.3 Sasthamkotta Lake (SL)
2.3.3.1.1. Location and area
Placed at an elevation of 33 m above MSL, the Sasthamkotta Lake, the largest
freshwater lake in Kerala (373 ha), is a designated Ramsar site since November,
Wetlands of Kerala
$!
2002. The lake is surrounded by low standing hills on all sides except south, where a
bund (embankment) has been built to store larger volume fresh water and separate
the lake from adjacent rice paddy fields. Water in the lake is special in that, it does not
contain common salt or other minerals and metals.
SL is located in Kunnathur Taluk of Kollam District, (76 °36¢ 27² - 76 °39 ¢55² E.
Long and 9 °00 ¢40 ² - 9 °04¢ 05² N Lat. Average depth of the lake was measured
as 6.53m and maximum depth as 15.2m.The soil around the lake for about 10 - 20 m
is mostly Kaolinite rich (derived from laterite) and hence, does not allow water to flow
into the lake to any appreciable quantity. Earlier it was believed that the lake owed its
supply mainly to the infiltration of ground water (Menon, 1967). However, later studies
showed that Sasthamkotta Lake is a rain fed lake showing increases in water level at
the end of monsoon rains. The yearly rainfall in the catchment area (area = 12.69
km2) of the lake is 282.16 cm and it has a storage capacity of 22.4 Mm3. It also
consists of extensive marshy land, wet paddy fields and water bodies like 'Chelur
pola' and 'Chirayathu Kayal'. An ancient Sastha Temple on its northern shores with
resident troupes of monkeys, lends its name to the lake and town, adds sanctity to
the waters and it is an important pilgrim centre
2.3.3.1.2 Physical setting
SL consists of two water bodies, viz., the main Sasthamkotta Lake and the adjacent
Chelur Kayal, separated by a laterite ridge. These water bodies are surrounded by
gently undulating lateritic hills on all sides except south where it is bordered by the
alluvial plains of the Kallada River. A number of smaller water bodies and waterlogged
areas occur in the river flood plains in the south and southwestern parts of Sasthamkotta
Lake.
Geomorphologically the area can be divided into the following units:
$"
•
Undulating uplands: This unit consists of nearly rounded or flat topped lateritic
mounts or hills with gentle slopes and intervening valley fills. The hill slopes
are fairly thickly vegetated mostly with mixed crops and plantations.
•
Valley fills: These are irregular valleys occupying the low-lying areas between
lateritic hills, mostly filled by alluvial and colluvial deposits. Presently they are
cultivated and densely populated.
•
Flood Plains/Alluvial plains: Vast alluvial deposits occur in the flood plains of
the Kallada River to the south. This unit is underlain by river alluvium mainly
sand and silt and is mainly cultivated. Several water bodies and waterlogged
areas occur in the flood plain.
Wetlands of Kerala
Fig.2.28: Sasthamkotta Lake and Environs (CED, 2003a)
Wetlands of Kerala
$#
2.3.3.1.3. Hydrology
The lake is separated from the flood plain by a 1.5 km long earthern embankment
constructed prior to 1956. The mean annual temperature is 26.70 in winter and
29.20 in summer, and the average annual rainfall is 2180mm. The hills, surrounding
the lake, cover an area of 935 ha, drainanage empties into lake.
The quantity of water stored in the lake is estimated as 22.4 Mm3. The maximum
water depth in the lake is about 13m. Water input to the lake is partly from of direct
rainfall on the lake basin (8 Mm3), from surface runoff and groundwater inflow from
the 935 ha. catchment (12 Mm3, assuming 60% runoff coefficient), thus making up
a total of 20 Mm3.The average depth to water table in the area is around 3.89 m
below ground level. Outflow from the lake is in four ways: spillage, groundwater
seepage, evaporation from the Lake surface, and pumpage for water supply. Only the
last two are known, the annual evaporation loss is of the order of 5 Mm3 (assuming
3.5 mm/d average evaporation), and the annual water withdrawal is 8 Mm3 at a
pumpage rate of 22 MLD (million litres per day) (KWA figures). These jointly constitute
about two- thirds of the inflow.
2.3.3.1.4. Biodiversity
About 110 species of herbs, shrubs and grasses and around 21 species of trees
have been listed from this site (table 2.15). The land adjacent to shore line is dominated
by grass species. In some areas, wild pineapple varieties have been planted for increasing
soil stability and to prevent soil loss. The watershed of the lake has mainly coconut
based agroforestry system with trees such as Mangifera indica, Anacardium occidentale,
Artocarpus integrifolia etc.
Table2.15: Biodiversity of the Sasthamkotta Lake (Compiled from various sources)
Groups
No. of species
Flora
Herbs, shrubs, clibers
Trees
110
21
Fauna
Fishes/prawns
29
Insects
13
Birds
34
About 13 species of insects have been identified from the area out of which 9 are
butterflies, 2 odonates and 2 hymenopterans. Twenty-seven species of fresh water
$$
Wetlands of Kerala
fish and two species of prawns were reported from Sasthamkotta Lake. Nearly 11
species of fishes are now available from Sasthamkotta Lake. This is attributed to the
fact that, Sasthamkotta Lake is a stand alone water body and does not have connection
with any other type of water bodies, whether stagnant or flowing. Migratory fauna is
also very scarce in and around Sasthamkotta. Since drinking water is supplied to
Kollam area from Sasthamkotta Lake, entire water body is separated from any inflow
by a long 'bund'.
Migratory birds like teals are also present in this wetland. A total of 34 species of
wetland dependant birds are reported from Sasthamkotta Lake. Out of which around
21% are long distance migrants.
2.3.3.1.5 Tourism
An ancient Sastha temple present near the lake lends its name to the town. So
mostly religious tourists visit here, their frequency is very low. However, tourism in
this lake is not welcomed by the people residing in Sasthamkotta as it alters the water
quality. Presently one privately owned row boat permitted by District Tourism Promotion
Council (DTPC) is being used for sight seeing. Accommodation is available at the
PWD (Public Works Department) Rest House.
2.3.3.2 Major Management Issues
2.3.3.2.1. Driving forces
The major driving forces of environmental change are agriculture (especially in the
banks of the lake), fisheries, services like water supply, sanitation, etc., households
and human settlements, pilgrimage, locally specific activities like washing of
clothes(dhobis) etc. The number of residents settled in the catchment has been on
the rise recently. Residents usually cultivate tapioca, paddy and plantain on the slopes.
The unscientific agricultural practices force soil erosion. Residues of fertilizers and
other chemicals used in the agricultural fields are draining into the lake. A good amount
of sewage and garbage from the homesteads in the catchment area is also reaching
the lake. The hut-dwellers soak dry leaves of coconut palm before matting which
used for thatching huts. Water is polluted by soaps and detergents used for washing
clothes and bathing.
2.3.3.2.2 Pressures
The water of Sasthamkotta Lake is used for supply of drinking water by Kerala
Water Authority to Kollam Municipality and suburbs. The lake serves as a major
source of water, sink for various pollutants and transformer in the cycling of nutrients,
chiefly carbon, nitrogen, sulphur and phosphorus. It also serves as an ideal habitat for
diverse flora and fauna. The lake offers considerable scope for fresh water aquaculture.
Wetlands of Kerala
$%
Population growth will put added pressure on resources because of the rising demand
for land for housing and other developments, demands on living resources for food,
recreation and fresh water. The increasing human settlements in the catchment area
of the lake also increases various types of stresses in the ecosystem in terms of
pollution due to solid waste, sewage, fertilizer residues and other chemicals, aesthetic
issues, etc
Other major pressures are (i)Reclamation of the land for agriculture along the
banks and adjacent areas, unscientific cultivation practices such as Tapioca cultivation
in hill slopes causing soil erosion (ii) Entry of agricultural and domestic waste including
sewage from surrounding area entering the lake, (iii) Pollution by used by professional
washer men (dhobis), (iv) Pollution from pilgrimage ultimately reaching lake and (v)
Land use Change - encroachment into the wetland creating various environmental
pressures on the landscape and habitat transformation and reduction in biodiversity.
The native inhabitants say that the area surrounding the lake supported greater number
of trees in the past and that it is now denudated. The number of residences on the
banks of the lake has been on the increase recently. There occurs pollution from local
tourists who visit the area. There is a ferry service across the lake transporting people
between West Kallada and Sasthamkotta. Dhobis are using the lake for washing
clothes.
2.3.3.2.3
State of Environment
The water quality data of lake are given in (table 2.16). Water quality meets all
standards of drinking water prescribed by regulatory bodies. Lake is kept protected by
separating it from any inflow of water from any source. The oxygen content of water
is usually high and turbidity is always below 10.
Table 2.16: Water Quality, Sasthamkotta lake (CED 2003a)
Site 1
Parameters
Colour
Colorless
Colorless
Odour
Nil
Nil
Depth ( meter)
16
17
pH (NTU)
7.06
7.06
Turbidity (mg/I)
19.4
19.2
7.2
7.2
Hardness (mg/I)
12
8
Acidity (mg/I)
10
20
Alkalinity (mg/l)
12
12
$&
Site2
Wetlands of Kerala
Salinity (ppt)
0.007
0.0052
Total Solids (mg/I)
4000
3400
3500
3200
500
200
6.403
4.80
11.2
20
0.0002
0.0003
0.004
0.003
-
0.4
Sulphide (mg/I)
Nitrite (mg/I)
A study conducted by Centre for Earth Sciences Studies, Thiruvananthapuram
shows that the dissolved oxygen is usually 4.49 mg/l and 3.33 mg/l (standard dissolved
oxygen should be >6). Magnesium content, which contributes to the hardness of
water, is very meager. The faecal Streptococci count is also within the limits. The
slight variation in acidity / alkalinity may be attributed to the fact that a lot of detergents
are getting added to the water body from 'bathing ghats' located by the side of
temple along the northern shore.
2.3.3.2.4
The unscientific cultivation of hill slope especially for annual crops like tapioca has
increased the soil loss by erosion and runoff into the lake basin leads to decrease in
water storage capacity. The change in land use and increasing agriculture in the
catchment indirectly reduce the ground water recharge, which has its repercussion in
the water availability in the lake.
2.3.3.2.5. Responses
The Sasthamkotta Fresh water Lake is one of the designated Ramsar Site in Kerala.
Prior to this declaration, several studies had been taken up by different agencies on
the conservation and management of the Sasthamkotta Lake.
Proposal for the implementation of Management Action Plan (MAP) for Sasthamkotta
Wetland was submitted by CWRDM through Govt. of Kerala to the Ministry of
Environment and Forests (MoEF), Government of India, during 1999. The MAP aims
at comprehensive development and management of the natural resources associated
with the Sasthamkotta Wetland System for its sustainable utilization and conservation.
The component of activities in the MAP included agro-forestry in the catchment,
sanitation and drainage, pollution abatement, limited desilting, weed control,
conservation of flora and fauna, fishery development, and awareness campaigns among
Wetlands of Kerala
$'
the local inhabitants. The programmes are expected to be implemented through Kerala
Water Authority (KWA), Department of Forests and Wild Life, Department of Fisheries,
State Fisheries Resource Management Society (FIRMA), District Rural Development
Agency (DRDA), CWRDM, etc. Sanction for MAP was accorded by the MoEF. The
action plan is being implemented with the support and overall supervision of Kerala
State Council for Science Technology and Environment, Govt. of Kerala
2.3.4 Periyar Reservoir (PR)
2.3.4.1. Introduction
2.3.4.1.1 Location and Area
Periyar Tiger Reserve (PTR) is located between 90 15' and 90 40' N Latitude and
760 55' and 770 25' E Longitude in Idukki District. The Reserve is unique and world
famous for its variety of large mammals. The formation of the reserve is closely
associated with the construction of Mullaperiyar Dam across the river Periyar in 1895
for diverting water to Tamil Nadu. As early as 1899 itself, the area consisting of 600
sq. km surrounding the dam was declared as Reserve Forests (Periyar Lake Reserve
Forests) by the then Maha Rajah of Travancore. The intention might have been to
protect the catchment area so as to prevent the dam from silting. This later led to the
formation of Wild Life Sanctuary in 1934. In 1950 another 177 sq km was added to
make the total area of 777 sq km, and was designated as Periyar Tiger Reserve in
1972. Recognising the importance of the reserve it was brought under the Project
Tiger in 1978 and to be known as Periyar Tiger Reserve. For management purposes,
the entire reserve is divided in to Core zone (350 km2), Buffer zone (377 km2) and
Tourism zone (50 km2). The core zone of the sanctuary was declared as National
Park in 1982.
2.3.4.1.2
Hydrology
Two streams Periyar and Mullayar and the lake with an area of 26 sq km form the
major aquatic ecosystem of the reserve. The Mullayar originating at an altitude of
about 1780 m at MSL has a length of 31 km and joins the southern tip of the lake.
The periyar Stream with a length 41 km, joins the eastern tip of the lake from south
originates at an altitude of 1593 m at MSL. The system is more or less a closed one
due to the presence of Mullaperiyar dam. The water from the reservoir overflows to
the down stream when it reaches 41 m though this happens very rarely (twice for a
couple of days in a decade). The only outlet of the reservoir is the tunnels from the
lake to the plains of Tamil Nadu. It also harbors the largest contiguous stretch of
evergreen forest. Due to all the above factors, Periyar area including the Lake holds
high conservation value.
%
Wetlands of Kerala
Fig.2.29: Periyar Reservoir and Environs (CED, 2003a)
2.3.4.1.3
Physical setting
The area in highland setting terrain characterized by steep to moderate hill tops,
rounded hill tops, ridges and escarpments. The most distinct feature of the physiography
Wetlands of Kerala
%
is the straight courses of stream segments oriented in specific directions, indicating r
strong control by major lineaments along N-S, E-W, NE-SW AND NW-SE directions.
The altitudes vary from about 870m to over 1300m. These hills are mostly covered by
dense to open forest, grass and plantation crops. Presently, the Periyar reservoir fills
a valley network.
Geomorphologically, the entire area comes under the denudational landforms. The
underlying lithology consists of the Archaean crystalline rocks such as charnockite,
hornblende and biotite gneisses and pink granite gneiss with basic dykes. The
topography is strongly controlled by major fractures (lineaments) and stream courses
are largely controlled by the latter. Denudational hills with smooth vegetated slopes
dominate the terrain. Though these are steep slopes and escarpments, most of the
summits are rather rounded. Fluvial terraces and valley fills occupy the valleys, but
most of these are cover by water at FRL.
Periyar Tiger Reserve (PTR) has been known to be a mega biodiversity zone due to
the rich and diverse ecosystems (table 2.17). There are five distinct vegetation types
identified within the sanctuary viz. evergreen, semi-evergreen, deciduous, grasslands
and secondary eucalyptus plantations. Evergreen and semi-evergreen forests are
found in the buffer and core zones and cover about 40% of the area of the reserve.
Due to the heavy stocking and presence of different layers, light penetration is low
and hence ground vegetation is not significant. The common tree species found in
similar forest types are also present here such as Cullenia exarillata, Dipterocarups
bourdilloni, Vateria indica, Canarium strictum, Artocarpus hirsutum, Callophyllum
tomentosum, Xylia xylocarpa and Gluta travancoria. The area surrounding the lake
and tourist zone has a mixture of semi-evergreen and moist deciduous forests
Table 2.17: Biodiversity of PR (Compiled from various sources)
Item
No. of
species
Flora
42
Trees
30
Phytoplankton
11
Fauna
%
Fishes
39
Insects
36
Birds
28
Wetlands of Kerala
interspersed with grassland both in the valley and hilltops. Large variety of common
deciduous trees such as Bombax malabaricum, Careya arborea, Pterocarpus
marrsupium, Lagerstroemia lanceolata, Tectona grandis and many species of Terminalia
and Fiscus are common place in these forests.
The grasslands are a distinctive feature of PTR, which are found often scattered
with clumps of dwarf Phoenix. Two type of grass lands are identified such as the
South Indian subtropical hill Savannah (grass lands with trees like Terminalia paniculata
and Emblica officinalis) and southern montane wet grass land (only grasses). The
main variety is elephant grass, which are commonly grazed by elephants, deer and
bison.
The rich flora of PR also supports large number of mammals, birds, reptiles,
amphibians and fish. Nearly 120 species of lower vertebrates and amphibians are
found in PR, of which 85 are endemic. There are 49 mammals identified which
include tiger, panther, wild dog, jungle cats, elephants, gaur, sambar, barking deer,
mousedeer, Nilgiri langur, bonnet macaque, lion tailed macaque, bear, porcupine jackal,
Indian giant squirrel, Malabar flying squirrel, wild boar, small Indian civet, common
palm civet, mongoose, hare, pangolins, Nilgiri Thar etc.
Periyar has a thick vegetation of forest and non-forest species. But only those
species lying in close proximity and under the influence of the Periyar Lake have been
considered here. Around 42 species of herbs, shrubs, grasses and 38 species of trees
were reported from here. Flora is mainly forest type dominated by tree species, in the
surrounding areas. But the sectors adjacent to the shore line have herbs, shrubs and
grasses. Other vegetation types in the vicinity include evergreen, moist deciduous,
grassland, scrub and degraded savanna. Eleven species of phytoplankton have also
been identified, of which many species are endemic to Western Ghats.
In a pioneering study fishes of Periyar reserve Chacko (1948) reported 35 species
in the system, While a recent study by Arun (1997) reported only 27 species from the
Periyar aquatic ecosystem (lakes and streams). Of these 14 are endemic to Western
Ghats and/or Periyar and 14 species have threatened status, while 9 are threatened
and endemic. All species of loach, except Malabar loach (Lepidocephalus thermalis)
are endemic to Western Ghats, and one among them - Travancore jonesi - has the
threatened status. Though two snakeheads are known in the system, these rarely
find a place in the catches. Of the 13 cyprinid species, 8 are endemic to Western
Ghats and 3 are exclusively endemic to Periyar Lake and streams. All endemic cyprinids
except Gara mullya are threatened, so are the cat fishes (Heteropneustes fossils and
Glyptothorax madraspatanam) and spiny eel (Mastacembelus armatus). Two species
viz., Tilapia (Oreochromis mossambicus) and European Carp (Cyprinus carpio communis)
are the exotics in the system, and were absent in Chacko (1948), which confirms the
Wetlands of Kerala
%!
fact that these were latter introduced in the system after 1948. These species also
occur in the Idukki reservoir down stream, again by introduction in mid 70s as part of
Fisheries Development programme (Gopinathan and Jayakrishnan, 1984).
Food - niche - competition between Tilopia and endemic species is one of the
reasons attributed for the vanishing of endemic species. Further, endemic species are
mostly restricted to flowing water conditions. But exotic species prefer stagnant
habitats, a positive factor utilizable for management of fisheries in this wetland. The
chief fish types are Kuil, Kooral, Gold, Tilopia, Chottavala, Aarakom, Kari, Varal, Karian,
Karimpachi, Pavukan, Kallotti, and Vazhakavarayan.
Bird population is considerably high in and around the water body, with about 30
species of migratory and endemic species, and many of these roost with nests at top
of the tree stumps. About 28 species of wetland - dependant - birds are on record
from Periyar Lake, out of which 27 % are long distant migratory type. Cormorants,
the most abundant birds at Periyar Lake, are followed by egrets, herons and storks.
Around 36 species of insects (i.e., including 20 butterfly species, 2 dragonflies, 5
wasps, 7 grasshoppers and 2 beetles) have been recorded. Land around Periyar Lake
has considerably fair grass population and tree species and the highest insect diversity
can be attributed to this.
2.3.4.1.5. Tribal Groups
Four tribal groups, viz., Mannans, Paliyans, Malaarayans, and Uralis, inhabiting the
environs of PTR, though once lived deep inside the forest were relocated at the
boundary of buffer zone, while creating the reserve. Now these communities live in
three settlements around the reserve, viz., Mannan and Paliyan at Labbakkandam
near Kumily, Malaarayans in Moozhikkal and Uralis at Vanchivayal settlement. The
Labbakandam colony is near the Lake. Among the tribal groups, Mannans are the
traditional fishermen. Considering the importance of fishing for the livelihood, forest
department has vested fishing rights to this community. Paliyans primarily depend on
dry wood gathering for sale and casual jobs, and at times though engaged in fishing.
2.3.4.1.6. Eco Development Committees (EDC)
EDC was launched in November 1998, has families residing around forest area as
members. There are 92 EDCs in the PTR, which helped reduce dependency on forests
and its products, by ensuring peoples participation in wild life conservation. EDCs also
help to control illegal felling of trees and poaching of animals and forest fire. The EDC
gets aid from local self-governments and intern provides assistance to fishermen,
deploys members as guides to visiting tourists, undertakes group farming, assists in
setting up cattle farms and help in starting provision stores.
%"
Wetlands of Kerala
2.3.4.1.7 Tourism
Thekkady, which comes under the confines of Periyar Tiger Reserve, is a major
tourist center in Kerala. Annually, thousands of domestic and foreign tourists frequent
this area to feel the thrill and joy of boating in Periyar reservoir for a glimpse of wild
elephants, tigers, leopards, bison, etc. in their natural habitat. Flora and fauna of the
area are nearly intact and protected with strictly monitored and controlled human
intervention. The use of plastics is strictly banned. The economic value of the wetland
may be considered the highest, when compared to other wetlands, because of the
income accruing from tourism.
2.3.4.2. Major management issues
Agriculture in the downstream areas, fisheries, households and human settlements,
services like water supply and irrigation, industry, tourism, research and academic
activities, local tribal activities etc are the major driving forces. Fishing in Periyar river
which runs through the Periyar Tiger Reserve is by tribals who use gill nets, traps,
hooks and baits. Water stored in the Mullaperiyar dam is utilized for irrigating three
districts of Tamil Nadu.
2.3.4.2.2 Pressures
Periyar is one of India's most visited but protected areas, hence environment around
the Lake suffers great pressure. Adequate steps are already positioned to protect and
conserve the area through many ecodevelopment programmes.
2.3.4.2.3 State of environment
PR and environment do not face problems with regard to pollution, since; it is
enclosed by evergreen forest on all sides. Water quality analysis is given in (table
2.18). (CED, 2003a) reported that there is no pollution and the only possible source of
pollution may be the motorized boats casting use of oil and grease.
Table 2.18 :Water Quality, Periyar lake (CED 2003a)
Parameters
Site 1
Colour
Colorless
Colorless
Odour
Nil
Nil
Depth ( meter)
1
9
pH (NTU)
-
-
18.8
20.2
6.4
7.6
Turbidity (mg/I)
Wetlands of Kerala
Site2
%#
Hardness (mg/I)
12
16
Acidity (mg/I)
10
10
Alkalinity (ppt)
32
32
Salinity (mg/I)
0.07
0.021
Total Solids (mg/I)
900
1200
400
600
500
600
9.8
13.13
52.48
51.2
0.0003
0.0005
0.24
0.256
_
3.2(gross)
2.4 (net)
Sulphide (mg/I)
Nitrite (mg/I)
2.3.4.2.4
Arun (1997) demonstrated that the number of fish species in Periyar Lake reduced
to 27 from 35 reported by Chacko (1948), warranting a complete ban on of fisheries
in the Lake, especially where it has the status of Tiger Reserve.
Prior to the founding of sanctuary, the tribals, viz., the Mannans and Paliyans were
totally depended on forests for their livelihood. But the creation of the sanctuary
curtailed their rights on forests, and infact were relocated to the periphery, along with
mandated concessions most important being fishing rights to Mannans in the Lake
and collection of dead-wood from the buffer zone, as well as the collection of nontimber forest products. As the part of the management and protection activities,
forest department employs number of tribals as firewatchers and protection watchers.
Besides, forest land is allotted to the tribals for cultivation; which has created a
positive impact on the quality of life of the tribal as well as their involvement in
conservation activities.
2.3.4.2.5 Responses
The PTR is a good example for how non-consumptive tourism and related activities
can be effectively implemented without causing any degradation to the forest
ecosystem. The EDCs working in the area utilized for the activities. The Periyar model
of participatory bio-diversity conservation is emerging as a dynamic and sustainable
example for the entire developing world.
%$
Wetlands of Kerala
2.3.5 KADALUNDI ESTUARY (KE)
2.3.5.1.1 Location and Area
Kadalundi estuary, lying at the boundary of Tirur taluk of Malappuram district and
Kozhikode Taluk of Kozhikode district (N lat 11049'36" and 1108'28" and E long
75049'36" and 75053'20"), is spread over 60 acres of mud flats rich in alluvium,
brought by Kadalundi River. The mud flats is exposed from September to May and
completely covered by water from June to August.
Figure 2.30 : Kadalundi Estuary and Environs (CED, 2003a)
Wetlands of Kerala
%%
2.3.5.1.2
Hydrology
The Kadalundi estuary has a very constricted neck and an unusually wide and
shallow wetland upstream dotted with small islands and mangroves. A large portion
of the shallow wetland is exposed during (diurnal) low tides with an average tidal
cycle of 12h 25m. The frequent exposure of the bed attributes unique characteristics
to the wetland. The main tributaries to Kadalundi are Olipuzha, Velli Ar and another
passing through the Perinthalmanna area. Kadalundi River originates at 1160 m at
MSL from Cherakkambam Mala, and has a channel length of 130km, before discharging
into the Arabian Sea.
As the summer discharge is very low, salinity intrudes into the estuary as far as
Mannathupara, 14 km upstream from the confluence, where a substantial urn structure
exists. The tidal fluctuations in this wetland are similar to what is observed in mediumsized estuaries elsewhere in the State (table 2.19).
Table 2.19: Tidal Fluctuation of Kadalundi Estuary (CWRDM)
Date
25.04.03
26.04.03
27.04.03
28.04.03
29.04.03
30.04.03
01.05.03
02.05.03
03.05.03
04.05.03
05.05.03
06.05.03
07.05.03
08.05.03
%&
High
Tide
Low
tide
0650
228
0710
230
0900
190
1100
198
1100
189
1210
201
1225
182
1300
188
1305
192
1330
202
1400
208
1440
211
1500
217
1515
1200
257
1230
258
1500
252
1700
254
1640
249
1700
256
1735
256
1825
251
1900
252
1950
247
2010
239
2100
236
2050
241
2105
219
251
Diff.
29
28
62
56
60
55
74
63
60
45
31
25
24
32
High
Tide
Low
tide
1650
230
1800
245
1000
174
2300
170
2250
183
2220
196
2315
180
2335
187
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
2200
249
2300
255
0525
248
0515
260
0600
246
0550
257
NA
NA
0650
255
0715
256
0800
256
0835
259
0910
249
0945
241
1020
NA
258
Diff.
19
10
71
90
63
61
68
Wetlands of Kerala
Kadalundi estuary has good mangrove vegetation along the sides of abutments
and pillars of the railroad bridge. Studies on the mangrove and other plant species
carried out by CED (2003a), reported that the predominant mangrove species is
Acanthus ilicifolius followed by Avicennia officinalis. Mangrove vegetation is almost
truly composed of true mangrove species but associates are very few. For this area
Simpson's index and Shannon Wiener's diversity index are 0.49 and 1.5 respectively.
Proper conservation and management efforts can ensure sustenance of very good
thick mangrove vegetation. The chief species are: Acanthus ilicifolius, Acrostichum
aureum, Aegiceras corniculatum, Avicenia marina, A. officinalis, Bruguiera cylindrica,
Derris trifoliata, Exocoecaria agallocha, Kandelia candel, Lumnitzera racemosa,
Rhizophora apiculata, R. mucronata, Sonneratia alba etc.
Kadalundi estuary has considerably good fish population as it is in close proximity
to the sea due to which both fresh water and marine fish - species are available. There
is a large fishworker community here dependent on this valuable resource, with common
species like Poozhan, Thirutha, Malan, Chemmeen (different varieties) etc.
The flora of the area consists of 19 tree species and 180 herbs, shrubs and climbers
(table 2.20). Around 34 species of fish and 19 species of insects including 12 butterflies
have also been identified (CED, 2003a)
Table 2.20: Biodiversity of Kadalundi Estuary (CED, 2003a)
Item
No. of
species
Flora
180
Trees
19
Fauna
Fishes
34
Insects
19
Birds
53
Kadalundi estuary has very large bird population of about 53 species, birds of the
order Charadriform, particularly family Caridae (Gulls and terns) dominate the estuarine
bird community. Brown and black-headed gulls are the most common. Terns, plovers,
sand pipers and stints are the next most numerous forms in that order. There are also
a large number of resident land birds like crows, bee-eaters, mynas, pigeons, parakeets
and water birds like reef and pond herons. The birds are seen mainly resting on the
Wetlands of Kerala
%'
mud flats adjacent to the Railway Bridge, only to feed on the very rich treasure of
small organisms like worms, crabs and other tiny creatures in the mud flats.
2.3.5.1.4 Tourism
Kadalundi area is scenically very beautiful with the estuary on one side and the sea
on the other and with thick luxuriant mangrove vegetation, where the latter is home
to a large number of migratory as well as resident birds. Consequently Kadalundi
holds very high tourism potential. The details of the non-consumptive tourism potential
for the Kadalundi estuary area are listed below:
a.
Potential for development as non-consumptive tourism hub with special thrust
to bird watching, game fishing etc.
b.
Boating using pedal and row boats has high potential in the area.
c.
A Biodiversity Interpretation Centre can be developed with special focus to
avifauna, mangroves and fishes.
d.
In addition to the local community support, the assistance from the Calicut
University can also be availed.
2.3.5.2 Major Management issues
The driving forces of environmental change are fisheries, aquaculture, small indutries,
household, shell mining, services like water supply and sanitation, activities of
researchers and academicians, and to certain extent tourism. There are around 200
persons engaged in fishing and around 50 families are involved in mussel cultivation
usually in high saline waters. Sand mining is also common in this area.
2.3.5.2.2 Pressures
&
•
The major issue in conservation of the mangrove area is the conflict
between local residents and conservationists (e.g., KFD, NGOs like KSSP
etc.). Natives are afraid of the growth of mangrove areas as it might
affect their livelihood, expose them to nuisance from the animals like
otter, snakes etc., inhabiting the mangrove and reduction of available
waterspread areas for coir retting. For instance, at some locations
mangrove trees have grown (intruded) into the private households and
the department prohibits clipping of the branches. Such factors led the
local community to block measures of mangrove conservation.
•
Dumping of solid waste, excreta coming of hanging latrines etc are
common. A number of conventional latrines with outlets leading to the
water body is also present.
Wetlands of Kerala
•
Several sites in the area are used for coir retting, leading to pollution of
water. Recent KFD decision to stop the coir retting adjacent to mangrove
areas, adversely affected the livelihood of people involved in coir making.
•
Siltation has affected many locations of the estuary especially when
sand mining is completely banned. Reclamation of estuary carried out by
members of local community, affecting the ecology of the estuarine
ecosystem.
2.3.5.2.3 State of environment
Water quality parameters do not show much variation. Pollution indicators show
slight variation in values (table 2.21). This may be attributed to the fact that Kadalundi
estuary is receiving a lot of pollutants in the form of domestic sewage. Also coconut
husk retting, which was once widely practiced in the area at one time and had been
banned in the open water body by the Kerala Forest Department, is now being carried
out in tanks and these effluents are also being let out into the estuary.
Table 2.21: Water quality, Kadalundi estuary (CED 2003a)
Parameters
Location
Balathuruthu
1
Colour
Colorless
Odour
Nil
Depth ( meter)
Mannenmedu
Oily
Balathuruthu 2
Penayenmedu
Brown
Colorless
Nil
Nil
Nil
1
0.4
0.45
0.25
pH (NTU)
7.60
8.03
8.07
8.18
Turbidity (mg/I)
18.7
23.4
38.6
48.1
Hardness (mg/I)
Acidity (mg/I)
5.6
5.6
6.4
6.4
6170
6100
6030
6110
20
10
Nil
Nil
Alkalinity (mg/I)
100
96
104
108
Salinity (ppt)
32.6
33.4
33.3
34.76
Total Solids(mg/I)
41400
41300
41900
43300
40200
41000
41600
39400
1200
300
300
3900
29773.27
30515.5
30433.06
31752.65
Sulphide (mg/I)
Nitrite (mg/I)
Wetlands of Kerala
1.6
5.6
4.8
2.4
0.04
0.099
0.051
0.095
0.159
0.08
0.2
0.17
_
0.4
_
_
&
Sanitation issues especially the "hanging Latrines" in the river shores, directly
discharging human excreta into the water body, is creating many environment and
health problems. The coconut husk retting creates pollution in many sites. The traditional
coir retting process has so many limitations and also makes use of land and water
body for the purpose.
In addition to mangroves present in public land there is one major mangrove patch
of 3.5 hectares, which is a private property. From the fishery point of view, the
mangroves here play an important role as a nursery ground for the early life stages of
fish and shellfish affording protection to these organisms from adverse conditions of
the open waters. The "capture" fishery does not interfere with the environment,
resource and recruitment of the coastal fisheries in any appreciable manner.
2.3.5.2.4 Impacts on population, economy and ecosystem
•
Depletion of bioresources due to loss of mangrove vegetation and intensive
aquaculture is a major threat to the environment.
•
The reduction in fishery resources leads to many socio-economic problems.
•
The activities initiated for non-consumptive tourism generates revenueas well
as helps in conservation is a positive impact on the economy and environment.
2.3.5.2.5 Responses
Keral Forest Department, based on the recommendations of a CED (2003a) study,
is now implementing an Integrated Approach to Mangrove Management by cpacity
building in the local communities, government agencies and grassroot level institutions
to restore conserve and utilize the mangrove wetlands in a sustainable manner. The
success of the project will ensure a symbiotic link between the "livelihood security of
coastal communities" and the "ecological security of coastal areas".
2.4 CONCLUSION AND RECOMMENDATIONS
2.4.1 Conclusion
Loss of the worlds wetlands poses an increasing problem because of loss of
important, ecological and economic values, perhaps irreversibly, when natural wetland
is transformed or degraded. Role of biodiversity in supporting the wetland system and
its resilience are not well known; however, the values offered by many wetland systems
to human society are extremely important. Although difficult to estimate, the total life
support function of wetlands may be particularly significant, as wetland comprises a
diverse range of marine, coastal, estuarine and freshwater habitats.
In Kerala, wetlands are under more extreme pressure compared to any other State,
which is attributed to relatively very high population density. Studies carried out in
&
Wetlands of Kerala
recent years point out the undesirable changes taking place in the geological, physical,
chemical and biological environment of the wetlands of Kerala. Partitioning by bunds,
reclamation and consequent shrinkage have been implicated as major reasons for the
destruction of habitat and dwindling of resources
With the rising population, pressure on land for agriculture, aquaculture, urban
expansion etc., too has increased. As a result of denuding, polluting, draining, filling
etc., these ecologically vital areas all over the globe have been under severe threat.
Threats to wetlands may be man made, natural or both. Direct human interventions
like reclamation for agriculture, urban expansion, housing development etc., totally
obliterate wetlands. Mining of wetland, construction of dams and check dams for
flood control, discharge of sewage, pesticide and weedicide residues degrade the
wetland to a large extent. Indirect threats include increased siltation due to unscientific
land use practices in the catchment area, mining, oil exploration etc. Added to these
are the natural causes like eutrophication, erosion, storm damage, drought, biotic
interferences other than anthropogenic etc. All these lead to the destruction of
wetlands, partly or totally.
The existing body of laws (within the federal structure of the Government of India)
applicable to wetlands can be classified into four categories, viz., central laws, state
laws, municipal laws as well as customary laws (sanctioning wise use or management
of wetlands). Under the Wildlife Protection Act (WPA) and other central acts, like the
Indian Forest Act, wetlands are not even defined as a separate category of ecologically
important areas, but instead generally form part of protected areas, especially when
wetlands are habitat of endangered wildlife (and exist within sanctuaries or national
parks). The existing laws would be amended to incorporate a broad inclusive definition
of wetlands (specifically in the WPA), to facilitate and make it legally binding for
wetland managers to draw up wetland conservation plans. Equally, it would make it
mandatory for the Government agencies (central and state) to offer institutional and
financial support for local wetland management and its wise-use-practices. The Wildlife
(Protection) Act of 1972 provides for establishing sanctuaries (section 18) and national
parks (section 35) and thus offers protection to wetlands which are within the protected
areas. However National Wildlife Law places a strict ban on grazing within a national
park, and hence human impact and thus helps the wetland ecosystem. This restriction
in national parks (which are zones of highest protection in protected area categories)
makes wise use or non-consumptive use of the wetland virtually impossible.
In India the conservation and wise use of wetlands are vested in the Ministry of
Environment and Forests (MOEF), the Department of Fisheries, the Ministry of
Agriculture, the Ministry of Water Resources, the Ministry of Surface Transport, the
Ministry of Power, the Ministry of Tourism and the Department of Ocean Development
Wetlands of Kerala
&!
of the GOI. Since land is a State subject, various State government agencies are also
involved in making decisions on wetlands (which are equated with land).
Keeping biodiversity under public good has been cited as one of the reasons for the
steady degradation. Peoples movements play a crucial role in influencing policy matters.
Ensuring community participation in planning and decision making at all levels and
local vigilantism with the involvement of Local Governments, and NGOs may help in
the effective implementation of the Environmental Management Plan (EMP). For such
reasons, a whole series of measures, concerning land-use in tourist areas should be
launched to remedy damages.
2.4.2 Recommendations
2.4.2.1 Legal, policy and institutional requirements
As a valuable natural resource, wetlands are to be preserved under the policy
resolution of sustainable development and environmental protection. Yet, there is no
comprehensive legislation for protection, conservation and management of wetlands
in Kerala. The term management is inclusive of utilisation, maintenance and
development of the wetlands, within the framework of a conservation policy. Hence,
there is an urgent need for enactment of policy procedure for the conservation and
management of wetlands in the State.
Local Self Government can help the sustainable development activities by formulating
and monitoring activities with peoples participation. Effective implementation of solid
waste management programme in all households shall be facilitated by the local
governments and in other sectors by implementation of Solid Waste Disposal Act,
2000. What is needed is a political will to go ahead. Legislation for conservation and
management of wetlands shall address the following aspects like:
(i)
Regulatory Mechanism
(ii)
Administrative Mechanism
(iii) Enforcement Mechanism
(iv) Participatory Management Approach
(v) Adjudicatory and Appellate Agencies
(vi) Punitive and Reformatory Measures
Additionally following measures need to be adopted:
&"
•
National Wetland Policy by the Ministry of Environment and Forests
•
Legal actions and policy decisions both at National and State level, to
prevent unauthorized and unscientific land reclamation.
Wetlands of Kerala
•
•
EIA for all reclamation and development projects, at or near the wetlands
and drainage basins and a mechanism for strict monitoring of the EIA
recommendation.
•
Pollution Control Board is to co-ordinate activities of various development
departments, and KSCSTE to reduce and eliminate wetland pollution.
•
Wetlands have archaeological, historical, cultural and scientific values.
Kerala has good potential to develop tourism industry centered on wetlands.
So the carrying capacity of wetlands vis-à-vis tourism should be
scientifically evaluated to regulate development activities. The following
multi-point check list should be verified in the process.
o
Preparation of an inventory of basic tourist resources.
o
Implementation of measures to conserve resources listed in the
Inventory.
o
Plans for tourism development are best used for tourism development.
Entrust tasks of conservation and management of bioresources with the LSGs,
like
Wetlands of Kerala
o
Effective implementation of solid waste management programme
in all households, to prevent dumping into the wetlands
o
Ensure community participation in planning and decision making
local vigilantism with involvement of LSGs and NGOs.
o
Environmental awareness and capacity building programme for
community and members of LSGs monitoring wetlands.
o
Mechanism to promote responsible tourism
o
Mangrove ecosystem though has a major role in the conservation
of wetlands, it faces a steady decline. Therefore, conservation
of existing mangroves and measures of regeneration of degraded
ones, as part of wetland management, are essential and can be
achieved by implementation of the Coastal Regulation Zone Act
under 6(1) category I (CRZ-I).
o
The Forset department shall adopt a programme for peoplecentered, process-oriented and science-based Joint Mangrove
Management (JMM). The benefits and lessons learned by JMM
shall be shared with, the mangrove user community (particularly
the women), local administrative departments, and NGOs,
&#
especially in the management functions like resource mapping,
planning, regeneration, protection, and benefit sharing.
o
Mangrove Conservation Corps (MCCs) and Green Police shall be
formed to be in charge of mangrove with the responsibility of
conservation and protection of the mangrove areas and in providing
leadership to regeneration/afforestation activities. The members
shall consist of representatives of local population, NGOs, different
stakeholders etc.
o
Eco - Adoption - Programmes: As many of the mangrove areas in
Kerala are in vested lands, facing severe threats in the form of
deforestation and reclamation. For example, Kadalundi a major
mangrove of about 3.5 ha, is a private land. Such land can be
purchased for conservation purpose by a consortium with funds
contributed by individuals / institutions, who are interested in
conservation of mangrove ecosystem. Such land shall be
apportioned among the members of consortium based on an
individuals level of contribution and with an agreement to utilize
the area only for conservation purpose.
2.4.2.2 Research Needs
Inspite of the fairly large volume of work carried out on the various aspects of
wetlands of Kerala, there is no public repository of data and summary embodied in the
documents. A programme for digitization and aggregation of all work irrespective of
bulk or origin or even language is highly imperative. Digital maps and cadastral maps
of wetlands shall be part of the repository and KSCSTE is the appropriate institution
for maintaining this archival data base. This data base should form the physical and
ecological backdrop of any new design for developing wetlands directly or indirectly
like the alignment of right of way of a new road or rail road.
Wetland maps presently available are in the scale of 1:2, 50,000 and 1:50,000
which are less than adequate for a detailed study. Formulation of management plans,
need maps of the scale of at least 1:25,000 scales or even lower. Remote sensing
data comes quite handy, in this respect, to map all the wetland areas.
There is a great need for inventorying the aquatic and wetland taxa in the tropical
world, especially in the face of the rampant habitat destruction that is taking place.
Aquatic ecosystems and wetlands are usually considered as wastelands and are being
reclaimed for various developmental needs, forcing several taxa, (which otherwise
would have a great potential value in medicine and other industrial uses), to the verge
of extinction. In Kerala, rising population pressure and the increasing demand for land
&$
Wetlands of Kerala
are taking a heavy toll of wetland. The presently available biodiversity studies on
wetlands of Kerala are mainly concentrated on the three Ramsar sites and some other
major sites. Most of the reports are chiefly with respect to the higher plants, fish,
avifauna and limited groups of micro-planktons. Comprehensive studies covering entire
biodiversity is lacking. Fauna other than fish and birds are almost neglected. Similarly
there is no account of most of the Pteridophytes, Bryophytes etc. The degree of
endemism in wetland areas is barely touched upon. So also there are no accounts on
the vulnerability of species and status of medicinal plants.
Though eco-tourism is an area now at sharp focus, todays emphasis on tourism
and tourism development are not devoid of ill effects. Proper documentation should
be carried out for each specific tourism site based on its carrying capacity with regard
to tourist inflow in order to design and to properly ensure the sustainability of tourist
trade.
Technological interventions are needed at times for the wise use of the wetlands.
The water quality of wetland system needs improvement and this could be best
achieved through various management interventions like, pre-treatmenting effluents
prior to discharge, regulating industrial growth, sustainable port and fisheries
development, improved transportation and modernization of coir industry. Enthusiastic
use of chemical fertilizers and pesticides needs to be regulated by integrated
management of agricultural practices, promoting organic farming etc. Non-intrusive
construction of road/rail bridges, against todays cost-cutting schemes of leaving a
narrower right of way for stream or estuary, needs to be practiced even at the design
stage itself, inorder to facilitate free flow of tidal currents which enhance the quality
of aquatic life.
A number of fishermen face fall-in-daily-catch often leading to group clashes among
them. Obviously, any new initiative regarding wetland or wetland related-region needs
careful scientific scrutiny prior to design and budgeting process.
Considering all the foregoing facts, the following research studies are suggested.
•
Documentation of wetland geometry, geomorphological setting, hydrology,
ecosystem status, trend etc., using synoptic satellite imageries and field checks
in a temporal mode.
•
Survey the existing mangrove forests quantitatively for the exact area, climatic
regime, rate of growth of trees and seasonal variations of environmental
parameters.
•
Election of suitable sites for Conservation Reserve and Community Reserve.
•
Capture data on responsible tourism potentials. An analysis shall be done
based on the following data:
Wetlands of Kerala
&%
o
Present supply of tourist services
o
Existing - infrastructure and present status of urban development
o
Road blocks in government and market services
o
Inventory and evaluation of tourist resources
o
Potential tourist demand and origin of tourists
o
Siting new areas suited for development of tourist facilities
o
Classification of areas in terms of environmental protection and
management
o
Design of tourist itineraries
o
Tourism planning in harmony with nature and environmental
conservation requirements
o
Alternative land uses vis-a-vis non-consumptive tourism.
o
Evaluation of possible and potential benefits to local economy.
•
Biodiversity Inventory and checklist of species with distribution, vulnerabilitystatus and economic value
•
Natural Resource Accounting of wetlands through community participation
and prioritization for conservation purpose.
•
Studies on organic production in wetlands
•
Developing models of Wetland conservation and management with participation
of local people.
•
Developing models for Local Economic Development of wetland dominated
areas and wise use of resources.
•
Training modules for Equipping LSGIs to carry out EIA studies for small scale
projects
•
Wetland Ecotourism Models
•
Modules for education and capacity building programmes for various
stakeholders
•
Cost effective technologies to reduce pollution of various sorts
•
Impact studies on tourism, sand and lime shell mining and changed agricultural
practices
•
Content and status of traditional knowledge system
&&
Wetlands of Kerala
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39.
Rama Rao, M. (1914). Flowering Plants of Travancore. Government
Press, Thiruvananthapuram, Kerala.
40.
Ramachandran, K. K., Mohanan, C. N., Balasubrahmonian, G., Kurien, J.
and Thomas, J. (1986). The Mangrove Ecosystem of Kerala: Its mapping,
inventory and some environmental aspects. (Unpublished Interim Report
1985-86). Centre for Earth Science Studies (CESS), Thiruvananthapuram,
Kerala.
41.
Raveendran, K. (2003). Diversity of marine fungi of Kerala coastal water.
Abstract on National symposium on prospecting of fungal diversity and
emerging Technologies Pune. pp 24.
42.
Remani, K. N. (1979). Studies on the effects of pollution with special
reference to benthos in Cochin Backwater. Ph.D. Thesis, University of
Cochin (unpublished).
43.
Remani, K.N., Venugopal, P., Saraladevi, K. and Unnithan, R.V. (1980).
Studies on the sediments of the Cochin backwaters in relation to pollution.
Indian J. Mar. Sci., 9: 111-114.
44.
Sabu, T and Babu Ambat (2007) Floristic Analysis of wetlands of Kerala.
Proc. 3rd Kerala Environmental Congress, Centre for Environment and
Development, Thiruvananthapuram. PP 91-105
45.
Sarala Devi, K., Venugopal, P., Remani, K.N., Lalitha, S. and Unnithan, R.
V. (1979). Hydrographic features and water quality of Cochin backwaters
in relation to Industrial Pollution. Ind. J. Mar. Sci. 8(3): 141-145.
46.
Saraladevi, K., Jayalekshmi, K.V., and Venugopal, P. (1991) Communities
and Co-existence of Benthic in Northern limb of Cochin Backwaters. Indian
J. Mar. Sci., 20: 249-254
47.
Sheeba, P. (2000) Distribution of benthic fauna in the Cochin backwaters
in relation to environmental parameters. Ph.D. thesis, Cochin University
of Science & Technology, Cochin.
48.
Thomson, K.T. (2003). Economic and Social Management of Estuarine
Biodiversity in the West Coast of India. http://coe.mse.ac.in/eercrep/fullrep/
mes/MES_FR_KTThomson
49.
Unnithan, R.V., Vijayan, M. and Remani, K.N. (1975). Organic pollution in
Cochin backwaters. Indian J. Mar. Sci., 4: 39-42.
50.
Unnithan, R.V., Vijayan, M., Ramakrishnan, E.V. and Remani, K.N. (1977).
Incidence of fish mortality from industrial pollution in Cochin backwaters.
Indian J. Mar. Sci., 6: 81-83.
Wetlands of Kerala
51.
Unnithan, V. K, Bijoy Nandan, S. and Vava, C.K. (2005) Fisheries and
environment assessment in selected backwaters on the south west coas
of India. Bulletin No. 139, Central Inland Fisheries Research Institute,
Barrackpore, Kolkata.
52.
Vannucci, M. (1987). Conversion of mangroves to other uses: the Cochin
backwaters. In: Umali, R.M. et al (Ed.), Mangroves of Asia and the Pacific:
State and Management. Ministry of Natural Resources, Manila, Philippines,
pp 331-336.
53.
Watzin, M.C. and Gozzelink, J.G. (1992). The Fragile Fringe Coastal
Wetlands of the Continental United States. Louisiana Grant College
Program, Louisiana State University, Baton Kange, LA; U.S. Fish and
Wildlife Service, Washington, DC and National Oceanic and Atmospheric
Administration, Rockville.
Wetlands of Kerala
'!
soe_kerala_v1_pages194-244
file:///C:/Documents%20and%20Settings/Envis/My%20Documents/so...
State of the environment report - 2007 - Vol. I
3.1 INTRODUCTION
Environmental problems are global and long-term. They can seriously impact human
health in many ways. In its 2005 edition, the State of the Environment report for Kerala
has included comprehensive material on water and air. In this edition, we will look at
environment and health, with special reference to water and vector borne diseases in
Kerala, and how they affect health. This is the reason for including a chapter exclusively
on environment and health1. This is a pilot initiative and is envisioned to set the stage for
future reports on issues related to health and environment.
3.1.1 Scope
The environment affects our health in many ways. However, this chapter will delve upon
two crucial areas: water and vector borne diseases. The DPSIR (Driving force, Pressure,
State, Impact, and Response) framework will be followed for reporting and analysis while
relating with other relevant issues, discussed in other chapters.
The chapter will consist of an overview of the various systems that are currently in place
in India and Kerala, that directly or indirectly deal with environmental health. This will be
followed by definitions of important terms, the facets of environmental health, the various
agents, and the mechanisms by which they exert adverse effects on human beings. Risk
assessment in terms of data on disease burden will be presented. This will be followed by
risk management, with respect to the attempts of the government in trying to mitigate
adverse environmental effects on public health. A separate section on emerging mosquito
borne diseases underscores the importance of these diseases in the state. The section will
examine in detail their prevalence, the recent epidemics and the control measures initiated
by the state.
Environment and Health
3.1.2 Approach and methodology
Relevant data was collected from the State Health Services, Central and State Pollution
Control Board (KSPCB), the Kerala Water Authority (KWA), and Department of
Drinking Water Supply (DDWS), Government of India. An extensive literature search
was carried out using resources from dedicated web sites of the Government of India, the
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World Health Organisation, national and international journals, newspaper articles, books,
and institutional publications from the libraries of the State Pollution control board,
governmental and non-governmental organisations.
3.2. OVERVIEW OF THE CURRENT INSTITUTIONAL SYSTEMS IN PLACE
· Ministry of health and family welfare: It is in charge of all medical and public health
matters and the implementation of various health schemes, with technical advice from the
Directorate General of Health Services in the centre and Directorate of Health Services in
the State.
· Central and State Pollution control board:
· The Central Pollution Control Board was constituted in September 1974 under the Water
Act, 1974. It provides technical services to the Ministry of Environment and Forests under
the provisions of the Environment Protection Act, 1986.
Main functions of the Pollution Control Board are:
(i) To promote cleanliness of streams and wells in different areas of the states by
prevention, control and abatement of water pollution
(ii) To improve the quality of air and to prevent, control or abate air pollution
· Kerala Water Authority was established in 1984 as an autonomous body of the
Government of Kerala. Its responsibilities are the design, execution and maintenance of
water supply schemes [1].
· An important indicator of coordination between different departments is how well data
and information flows across various departments and institutions. The table 3.1 shows
that data is collected at regular intervals by various departments. What is entirely missing
is the inter-departmental sharing of this information.
3.2.1 Overview of current policy
The National Health Policy 2002 aims at a reduction of mortality by 50% on account of
TB, Malaria and other vector borne diseases; and elimination of lymphatic filariasis by
the year 2015. The State Health Policy, which is in a draft form, implements the policy in
the State.
Table-3.1 : Information flow in the State, with respect to monitoring of water
quality
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The following figure 3.1 depicts disease related information flow in the health
department. The health care workers at the village level actively collect information
regarding diseases by undertaking house to house visit. Passive data collection also
happens at public hospitals like PHC, Taluk Hospitals. Information pertaining to diseases
collected at the grass root level by health workers is consolidated first at the PHC and
then sent to the Mother PHC. At the district level, data from different PHCs and Taluks
are consolidated and sent to State level. Monthly meetings are held at PHC, CHC, District
and state level to analyse the collected data. In summary, the data flow is bottom up,
reaching the Directorate of Health Services in the state capital.
3.3 WATER BORNE DISEASES
An increase in population as well as population density, along with rapid urbanization has
led to increased demand and consumption of water, and a reduction in the per capita
availability of water. All these have had an impact on water borne diseases, which will be
described in detail in the coming sections using the DPSIR framework.
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State
District
Taluk
Block
Panchayat
Village
Figure-3.1: Flow of information with respect to diseases:
Box-3.1: Definitions
Public Health definition of environment:
1. All that which is external to the individual host. It can be divided into physical,
biological, social, and cBox-3.1: Definitions
ultural factors, any or all of which can influence health status in populations[2].
2.Environmental health comprises those aspects of human health, including quality of life,
that are determined by physical, biological, social, and psychosocial factors in the
environment. It also refers to the theory and practice of assessing, correcting, controlling,
and preventing those factors in the environment that can potentially affect adversely the
health of present and future generations (WHO).
3. National Institute of Environmental Health Sciences (NIEHS) charter definition:
Environmental Health Sciences is the study of factors in the environment that affect
human health. These factors represent chemical, biological, or physical agents contained
in air, water, soil, or food, and are transported to humans via inhalation, ingestion, or skin
absorption. The net effect is production of adverse health effects.
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4. Facets of environmental health
Environmental epidemiology and environmental toxicology deal with the causal
mechanisms between exposure and subsequent development of disease. Environmental
engineering deals with factors that govern and reduce exposure. Preventive medicine
deals with factors that govern and reduce disease development, and the study of Law is
important for the development of appropriate legislation to protect public health.
Water-borne diseases from faecal contamination are one of the biggest public health risks
in India _ diarrheal diseases are the largest killers of children. Repeated bouts of diarrhea
also cause stunting through malnourishment _ children with diarrhea are unable to absorb
the nutrients from any food they eat. It has been argued that India loses 90 million days a
year due to waterborne diseases, costing Rs 6 billion in production losses and treatment.
Another study estimated that each year India lost 30.5 million `disability-adjusted life
years' because of poor water quality, sanitation and hygiene [3].
Water borne diseases are the most important issues of water quality in India. They are the
result of inadequate arrangements for transport and treatment of waste. Waste-water is
discharged into the natural water sources without treatment, leading to contamination of
surface and ground water. A large population of the country uses water directly for
drinking without any treatment or with limited treatment, thus exposing them to water
borne diseases. A vast majority of water quality problems are caused either by
contamination or over exploitation, or a combination of both [4].
Infectious diseases caused by pathogenic bacteria, viruses and parasites (e.g., protozoa
and helminths) are the most common and widespread health risk associated with
drinking-water. The public health burden is determined by the severity of the illness
associated with pathogens, their infectivity and the population exposed (table 3.2).
Table-3.2: Water borne diseases
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3.4. DPSIR framework
Figure-3.2: Humans and their environment
3.4.1 Driving force
Human needs and wants drive choices that produce environmental impacts which, in turn,
may result in adverse health consequences. With a population that is 16% of the world's,
India has a mere 2.45 % of the world's land resources and 4% of its water resources [5].
The population growth coupled with high population density and rapid urbanization is a
major driving force. A limited awareness on hygiene and spread of diseases has lead to a
total lack of concern among citizens about environmental issues.
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3.4.2 Pressure
Due to an increase in unplanned urbanization and industrialization, the environment has
deteriorated significantly. Pollution from a wide variety of emissions, such as from
automobiles and industrial activities, has reached critical levels in many urban and
industrial areas, causing respiratory, ocular and other health problems. Monitoring of the
urban environment in selected cities in recent years by the pollution control authority has
identified 21 critically polluted areas in the country [6]. Agricultural activities including
widespread use of fertilizers, pesticides and weed killers also alter the environment and
create health hazards. Water stagnation and the consequent multiplication of vectors have
increased the risk of vector-borne diseases. The risk associated with disposal of hospital
wastes has added to the overall unhealthy situation.
Pressure in the form of environmental agents can be chemical, biological and physical.
Vectors can be water, air, soil, food. Routes of entry are typically through inhalation,
ingestion or absorption.
Source: Adapted from Ìntroduction to Environmental health',
Jonathan M.Links, Johns Hopkins University
Figure-3.3: Routes of exposure
The table 3.3 describes the major types, sources, environmental distribution and pathway
of environmental agents.
It is important to note that the major pathway is either through food, water or air, making
them the most important routes of environmental exposure to toxins. These noxious
agents interact with biological systems, and exert adverse effects on human beings, and
are detrimental to public health.
Table-3.3: Environmental agents
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3.4.3 State
Because of the above mentioned pressure, the State of affairs is grave because of
pollution of water resources and inadequate amount of good quality water. This leads to
an impact on human health, as will be seen in the next section.
3.4.4. Impact
The Impact of water borne diseases on human health is in the form of different
manifestations. Vectors borne disease like Malaria, Leptospirosis, Japanese encephalitis,
Chikungunya and Dengue are threatening to re-emerge. Other manifestations are in the
form of flurosis, (due to high fluoride content in water), as recurrent stomatitis due to
Nitrate contamination, or as Diarrhea in districts with high population density.
3.5 CRITICAL ISSUES
Some critical issues with respect to environment and health, especially with relevance to
water are access to adequate quantity of water of reasonable quality, access to sanitation,
surveillance and chemical contamination of water
Poor water quality continues to pose a serious threat to human health. Each year,
worldwide, an estimated 4 billion episodes of Diarrhea result in an estimated 2 million
deaths, mostly among children [7]. According to the WHO, 88% of that burden is
attributable to unsafe water supply, sanitation and hygiene and is mostly concentrated on
children in developing countries.
3.5.1 Access to adequate quantity of water of reasonable quality
Minimum acceptable standard of water for living as recommended by WHO is 2-3
liters/day for drinking and 20_50 liters per-capita per day for cooking and basic hygeine.
From the public health standpoint, the proportion of the population with reliable access to
safe drinking-water is the most important single indicator of the overall success of a
drinking-water supply programme. WHO and UNICEF define "reasonable access" to
improved water sources as being "availability of at least 20 litres per person per day
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within one kilometre of the user's dwelling" [8].
The water resources in India are unevenly distributed in time and space. Since most
rainfall occurs only during 3 to 4 months of the year, assured water supply to agriculture,
industries and drinking purposes is a challenge. It is estimated that only 70 percent of the
people in urban areas have access to basic sanitation services. A large number of rural
habitations remain without any identified source of safe drinking water (figure 3.4). The
rising consumption will aggravate the water scarcity. The total consumption in India is
expected to rise by 20-40 percent over the next 20 years. Agriculture accounts for 89
percent and domestic consumption accounts for 4.8 per cent of the total water
consumption in India. Per capita availability is 1820 cubic meter and per capita storage is
207 cubic meter [9].
Inadequate quantity of water is generally due to the following:
· Vulnerability of surface water to drought i.e., lakes, reservoirs
· Diversion of rivers for agricultural and urban use
· Declining groundwater levels due to ever increasing demand for water for agriculture,
domestic and industrial activities, leading to the over-exploitation of water resources
· Failure to replenish due to uneven distribution of rainfall in time and space
· Increasing competition for water supplies
Source: Economic survey 2005-2006 Government of India available at
http://indiabudget.nic.in/es2005-06/chapt2006/tab96.pdf
This comparison is based on the data entered for 5382 habitations out of total 7573
habitations in the state of Kerala as per 17th February 2007.
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Figure-3.4: Comparison of access to safe drinking water in households in India and
Kerala
Table :3.4 Drinking water quality standards as recommended by WHO and BIS
Source: WHO. 1986. WHO Handbook. Geneva: World Health Organization.
ISI. 1991. Indian Standards (IS: 10 500). New Delhi: Indian Standards Institute.
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Box-3.2: Traditional practice of drinking hot water with herbs in Kerala
As reported in the first edition of State of the Environment report, more than 90 percent
of wells in Kerala have been affected by pollutants from sewage, and well water still
remains one of the major sources of drinking water in Kerala. Water tests in the villages
of Thiruvananthapuram revealed the presence of coliform in three out of four cases, yet
no major health problems were reported. This may be attributed to the practice of boiling
water before drinking. [Impact of population growth on water and quality of life. New
Delhi: Tata Energy Research Institute. T E R I. 2002. TERI Project Report
No.1999RD42] http://www.teriin.org/projects/ES/ES1999RD42.pdf ]. Boiling water
before drinking is a time tested method of water purification, but this tradition is being
gradually replaced by the increasing use of bottled water. There is no scientific study yet
to establish the effectiveness of this traditional practice. If proven effective, this has the
potential to change the impact of many water borne diseases on human beings and can be
shown as another Kerala Model of achieving good health outcomes with traditional
knowledge.
3.5.2 Access to sanitationThe proportion of the population with safe drinking water available at home or with
reasonable access was 92.6% in 1998-99 for urban areas and 72.3% for rural areas. The
proportion of the population with adequate excreta disposal facilities was 80.7% in
1998-99 in urban areas and 18.9 in rural areas. At the time of formulation of the 8th plan,
it was estimated that with regard to water there were about 3000 `no source' villages out
of a list of `problem' villages numbering 162,000. Besides this, about 150,000 villages
were only partially covered. Regarding urban water supply, the service levels are far
below desired norms. During the mid 90s, an accelerated urban water supply programme
was initiated for towns having less than 20,000 population. The provision of hygienic
sanitation facilities through conventional sewage and on-site low cost sanitation has not
been given priority. Though the 8th plan envisaged conversion of all existing dry latrines,
the final result is still nowhere near the target. The main constraints with regard to water
supply are inadequate maintenance of rural water systems, lack of finances and poor
community involvement. Most municipalities have a limited system for monitoring the
quality of water, with contamination causing episodes of water-borne diseases even in
metro cities like Delhi and Calcutta. Most of the people in rural areas are not aware of the
health and environmental benefits of improved sanitation [6]. Diarrhea is the most
common disease,
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and human excreta are the most common contaminants. Sanitation is generally a more
pressing need than water supply in some conditions.
3.5.3 Surveillance
Pathogen identification- Presence of fecal contaminants remains the most sensitive and
specific way of assessing pathogen identification. A major indicator of fecal
contamination are E-Coli and spores of sulphite.
Mechanism: Pathogenic microbes pass through the host and enter the aquatic ecosystem
by way of contamination from human and animal wastes. They cause cholera and other
diseases. Confirmed diarrheal serotypes of E.Coli were isolated from the Cochin estuary
and were found to be highly resistant to most of the antibiotics. 21% of total E.Coli were
entero pathogenic, entero toxigenic, entero hemorrhagic and uropathogenic strains, which
can cause significant mortality and morbidity among children [10]. In addition, certain
construction activities may lead to stagnant water and create opportunities for vector
borne diseases.
Box-3.3
According to the data published by Ministry of Rural Development, till 17th February
2007, out of 7174 schools, 57% have toilets, 62% have drinking water supply and 72%
have hand washing facilities. [The Baseline Survey Data. School Sanitation Program.
Ministry of Rural Development, NIC-Dept. of Drinking Water Supply]
In a research study conducted in 1998 in Trivandrum, it was found that school children
who use foot wear and had access to toilet facilities had less number of ova in their stool.
There was almost complete absence of hookworm and pinworm ova, but roundworm and
whipworm ova were present in almost all settings. This calls for more attention of
personal hygienic measures in schools. [Kutty VR, Soman CR, Kumar KV. Pattern of
Heminthic infestation in school children in Thiruvananthapuram district. Discusion paper
number 19, May 2000. Kerala research Program on local level development]
3.5.4 Chemical contaminants
Both organic and inorganic chemicals can contaminate drinking water. The source of
contamination can be natural or man made table 3.5. The routine data collection process
collects information from the habitat level and is regularly reported to the Swajaldhara
Program. Routine data is collected on four chemicals; Arsenic, Fluoride, Iron and
Nitrates, in addition to data on water salinity. The reported data seems to indicate that
Arsenic was
found in three villages of two districts in Kottayam and Malappuram of Kerala. It is however
a known cause of illness in other states of India, especially West Bengal [11].
The most commonly reported inorganic elements in water are Fluoride, Iron, Nitrates and
mixed contamination of the three figure 3.5. Not all the chemicals cause adverse health
effects, Some of them are essential elements and some others are beneficial to human health
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within a limit, like fluoride. Most of these chemicals exert their effect after prolonged
exposure.
Table-3.5: Source of chemical contaminants
Figure-3.5: Chemicals affecting water in Kerala
Source: Ministry of Rural Development, NIC-Dept. of Drinking Water Supply. Bharat
Nirman Programme Department of Drinking Water Supply, Ministry of Rural
Development
Govt.
of
India
Report
Printed
on
17/02/2007
.
http://ddws.gov.in/bnp_hab/rep_wqaffected_05.asp?stcode=16&flag=1 ]
[Habitation consists of people living in wards].
3.5.4.1 Fluorides
Fluoride exists fairly abundantly in the earth's crust and can enter the groundwater by
natural processes; the soil at the foot of mountains is particularly likely to be high in
fluoride from the weathering and leaching of bedrock with high fluoride content. In
drinking water, fluoride is tasteless, odorless, colorless and totally soluble. Its detection
requires laboratory equipment and specially trained personnel. Levels of daily exposure of
fluorides depends on the geographical area, though diet containing fish and tea may also
contribute to the Fluoride intake[12].
Fluoride in water primarily produces effects on skeletal tissues (bones and teeth). Low
concentrations provide protection against dental caries, especially in children. The preand post-eruptive protective effects of fluoride increase with fluoride concentration up to
about 2 mg/litre of drinking water; the minimum concentration of fluoride in
drinking-water required to produce it is approximately 0.5 mg/litre.
Fluoride can have an adverse effect on tooth enamel and may give rise to mild dental
fluorosis at drinking-water concentrations between 0.9 and 1.2 mg/litre, depending on
intake. Elevated fluoride intakes can also have more serious effects on skeletal tissues.
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There is evidence of an increased risk of effects on the skeleton at total fluoride intake
above about 6mg/day.
[Source: Bharat Nirman Programme Department of Drinking Water Supply, Ministry of
Rural Development Govt. of India ]
Figure-3.6: Number of habitations affected by fluoride in water
Fluorosis is considered endemic in 14 states of India. Dental fluorosis is the most
convenient biomarker of exposure to fluoride. There are 11 villages and 13 habitations in
Kerala affected by high Fluoride content, as on 18th January 2007. (Figure 3.6).
According to a 2003 survey, it is endemic in Idduki, Palakkad and Thiruvanthapuram
districts where 45 habitations of 23 Panchayats are affected [13]. In a community-based,
cross-sectional survey of school children in Ambalappuzha taluk, Alappuzha district, the
prevalence of dental fluorosis among school children aged 10-17 years was found to be
35.6%.[14]
Box-3.4
Addressing fluoride excess in drinking water:
Nalgonda Technique developed indigenously is a low cost flocculation method for
treating drinking water with high fluoride content. Adsorption method with use of
Alumina or similar products might are also considered useful in case of use in hand
pumps. Taking into consideration the high average rain fall in Kerala , appropriate use of
rain water for drinking purpose after treatment can be considered.
3.5.4.2 Iron
Iron is one of the earth's most plentiful resources, making up at least five percent of the
earth's crust. Rainfall seeping through the soil dissolves iron in the earth's surface and
carries it into almost every kind of natural water supply, including well water. Although
iron is present in our water, it is seldom found at concentrations greater than 10
milligrams per liter (mg/1) or 10 parts per million (ppm). Iron is not considered hazardous
to health. In fact, iron is essential for good health because it transports oxygen in blood
and is an essential element in human nutrition. Estimates of the minimum daily
requirement for iron depend on age, sex, physiological status and iron bioavailability and
range from about 10 to 50mg/day.
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In Kerala, 341 villages in 378 habitations have been affected by high Iron content in
drinking water (figure 3.7). Iron is a troublesome contaminant of home water supplies
When the level of iron in water exceeds the 0.3 mg/l limit, we experience red, brown, or
yellow staining of laundry, glassware, dishes and household fixtures such as bathtubs and
sinks. The water may also have a metallic taste and an offensive odor. Water system
piping and fixtures can also become restricted or clogged. When iron exists along with
certain kinds of bacteria, problems can become even worse. Ìron bacteria consume iron
to survive and leave a reddish brown or yellow slime that can clog plumbing and cause an
offensive odor. No health-based guideline value is proposed for Iron By World Health
organization [15].
[Source: Bharat Nirman Programme Department of Drinking Water Supply,
Ministry of Rural Development Govt. of India ]
Figure-3.7 : Number of habitations affected by iron in water
3.5.4.3 Nitrate
Nitrate is an inorganic compound that occurs under a variety of conditions in the
environment, both naturally and synthetically. Nitrate does not normally cause health
problems unless it is reduced to nitrite. Nitrate is used mainly in inorganic fertilizers, and
sodium nitrite is used as a food preservative, especially in cured meats. The nitrate
concentration in groundwater and surface water is normally low but can reach high levels
as a result of leaching or runoff from agricultural land or contamination from human or
animal wastes as a consequence of the oxidation of ammonia and similar sources. The
formation of nitrite is as a consequence of microbial activity and may be intermittent.
Nitrification in distribution systems can increase nitrite levels, usually by 0.2_1.5 mg/litre.
Short-term exposure to drinking water with a nitrate level at or just above the health
standard of 10 mg/l nitrate-N is a potential health problem primarily for infants. Babies
consume large quantities of water relative to their body weight, especially if water is used
to mix powdered or concentrated formulas or juices. Also, their immature digestive
systems are more likely than adult digestive tracts to allow the reduction of nitrate to
nitrite, which can lead to methemoglobinemia or "blue baby" disease.
In Kerala, 59 villages from 67 habitations are affected by nitrate, especially Malapuram
district figure 3.8. Nitrate in drinking water starts affecting the health of the general
population at the level of 100 to 200 mg/l. Some of the nitrate consumed can be converted
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in the body to nitrite, which under appropriate circumstances can combine with amines
(portions of protein molecules often found in foods, medications, cigarette smoke,
decaying plants, soil, and sometimes water) to form nitrosamines, which are welldocumented
[Source: Bharat Nirman Programme Department of Drinking Water Supply,
Ministry of Rural Development Govt. of India ]
Figure-3.8 : Number of habitations affected by nitrate in water
cancer-causing substances. So far, the only studies linking nitrate in drinking water with
cancer have involved nitrate levels that are quite high (at or above 100-200 mg/l
nitrate-N).
3.5.4.3.1 Sources of Nitrate:
Eighty to 90 percent of the nitrate most people consume comes from vegetables, but this
is unlikely to cause health problems because very little of the nitrate in vegetables is
converted to nitrite. Meat products account for less than 10 percent of nitrate in the diet,
but 60 to 90 percent of the nitrite consumed. This is primarily because of sodium nitrite
added to some non vegetarian foods. Fruits, grains, and dairy products contribute almost
no nitrate or nitrite to people's diets. Studies from India suggest the association of nitrate
with recurrent stomatitis [16].
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Box 3.5
Removal of Nitrate from Drinking water:
There are no simple ways to remove nitrate from water in the home. Because nitrate
does not evaporate the way chlorine does, boiling, freezing, or letting water stand
does not reduce the nitrate level. In fact, boiling water for more than 10 minutes can
make the nitrate more concentrated. Distillation systems, reverse osmosis and Ion
exchanges method though can address the issue but have serious limitation interms
of cost/and maintenance. The best solution is to find an alternative water supply for
drinking and cooking water purposes.
3.6 DISEASE BURDEN
Adverse health effects may be acute or delayed in onset, clinical or sub clinical,
reversible or irreversible figure 3.9.
The data represented here is from government health centers only. It underscores the
point that there are many more cases of diarrheal diseases than are depicted here. As
mentioned in the methodology section, there is a limitation of this data. Studies on
utilisation of health services in Kerala reveal that 23 to 28 per cent of acute illness
get reported to
(The Ìceberg' Phenomenon of disease epidemiology)
Figure-3.9: Severity of adverse effects on populations
the government hospitals for treatment. Of the rest, 58 to 66 per cent go to private
hospitals and approximately 5 per cent go to co-operative and other medical
institutions[17].
A significant proportion of waterborne illness is likely to go undetected by the
communicable disease surveillance and reporting systems. The symptoms of
gastrointestinal illness are usually mild and only a small percentage of those affected will
see a doctor. Among these, only a minor proportion will have their stools microscopically
examined. So, the number of reported cases represents only the tip of the iceberg, as
shown in figure-3.10.
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Figure-3.10: Diarrheal diseases in Kerala- district wise
Drinking-water is the most probable vehicle of transmission for pathogens transmitted by
the faecal-oral route. Contamination of food, hands and utensils also plays an important
role. Improvements in general hygeine and mechanisms of excreta disposal are necessary
conditions for reducing faecal-oral disease transmission. The figure 3.11 shows that
certain districts are more prone to water borne diseases. Reduced water supply and
compromised sanitation practices may be some of the reasons. Communicable diseases
that are mainly spread by unhygenic food and water are diarrhea, dysentery, cholera,
typhoid and viral hepatitis (jaundice).
The proportion of the population with safe drinking water available at home or with
reasonable access was 92.6% in 1998-99 for urban areas and 72.3% for rural areas. The
proportion of the population with adequate excreta disposal facilities was 80.7% in 1998Environment and Health
Data source: Directorate of health services, Kerala
Figure-3.11: Food and water borne diseases in Kerala in 2005
As seen in the figure 3.12, the safety of water supply is compromised in the monsoon
months, leading to an increase in diarrheal cases.
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Data source: Directorate of health services, Kerala
Figure-3.12: Seasonal variation of diarrheal diseases in Kerala for '04-'05
99 in urban areas and 18.9 in rural areas. The main constraints with regard to water
supply are inadequate maintenance of rural water systems, lack of finances and poor
community involvement. Most municipalities do not have any system for monitoring the
quality of water, with contamination causing episodes of water-borne diseases [18]. In
Kerala, the percentage of population covered according to 2005 data , was the lowest in
Kozhikode district (49.21%). It also has the highest number of diarrheal cases.
3.6.1 Leptospirosis
Leptospirosis is the most widespread zoonosis in the world. It is mostly an occupational
disease especially in rural areas. Leptospirosis is a bacterial disease that affects both
humans and animals. The early stages of the disease may include high fever, severe
headache, muscle pain, chills, redness in the eyes, abdominal pain, jaundice,
haemorrhages in skin and mucous membranes (including pulmonary bleeding), vomiting,
diarrhoea and a rash. Pathogenic Leptospira spp. cause leptospirosis. Human infection
occurs through direct contact with the urine of infected animals or by contact with a
urine-contaminated environment, such as surface water, soil and plants. The causative
organisms have been found in a variety of both wild and domestic animals, including
rodents, insectivores, dogs, cattle, pigs and horses. Leptospires can gain entry through
cuts and abrasions in the skin and through mucous membranes of the eyes, nose and
mouth. Human-to-human transmission occurs only rarely.
Leptospirosis occurs worldwide, in both rural and urban areas and in temperate and
tropical climates. It is an occupational hazard for people who work outdoors or with
animals, such as rice and sugar-cane field workers, farmers, sewer workers, veterinarians,
dairy workers and military personnel. It is also a recreational hazard to those who swim or
wade in contaminated waters. In endemic areas the number of leptospirosis cases may
peak during the rainy season and even may reach epidemic proportions in case of
flooding.[19]
Leptospirosis is an infection in rodents and other wild and domesticated species. Rodents
are implicated most often in human cases. The infection in man is contracted through skin
abrasions and the mucosa of the nose, mouth and eyes. Exposure through water
contaminated by urine from infected animals is the most common route of infection.
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Human-to-human transmission is rare.
Weekly epidemiological record published by WHO 1999, reports a total of 977 cases of
leptospirosis in Kerala. [20] In a study at Kolenchery involving 976 cases of leptospirosis
confirmed by culture and/or serological tests. Serogroups Autumnalis, Australis and
Icterohaemorrhagiae were the commonest. Mortality rate was 5.32%. The increase in
incidence was attributed to the geographical characteristics, continuous moisture of the
soil due to irrigation in summer and year-round cultivation making food and cover
available to host rodents. Close interaction of humans, animals, soil and water in this
region make the spread of leptospirosis to humans easy. [21]
Figure-3.13: Reported cases of leptospirosis in Kerala in 2003-05
Outdoor and agricultural workers (rice-paddy and sugarcane workers for example) are
particularly at risk but it is also a recreational hazard to those who swim or wade in
contaminated waters. In endemic areas the number of leptospirosis cases may peak during
the rainy season and even may reach epidemic proportions in case of flooding because the
floods cause rodents to move into the city.
National Institute of Communicable Disease, New Delhi, investigated the epidemic of
Leptospirosis in Kerala in the year 2000. A total of 10 cases and 5 deaths due to
leptospirosis was reported from Pathanamthitta and Thiruvalli Municipalities of
Pathanamthitta district. All these cases were reported during July, 2000 with all the five
deaths occurred among adults aged between 37 to 55 years. [22]
The situational analysis done by RMRC (Regional Medical Research Center Port Bailr)
during septemeber- October 2002 found that three districts via. Kottayam, Alleppey and
Calicut are the worst affected by leptspirosis , with sero prevlance rate of 7%-9% among
healthy individuals. The team of investigators suggested that this prevalence rate is
significant to consider Leptospirosis as a major public health problem and also suggested
that the annual incidence rate of infection in the areas studied could be in the range of 3 5%. [23]
In the year 2002 a total of 1443 suspected cases with 140 deaths were reported in the state
19th September 2002 all over Kerala with Kozhikode and Ernakulam districts having
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higher incidence than other districts. About one third of cases were found to be
serologically
Figure-3.14: Seasonal pattern of leptospirosis in Kerala during 2004-05
positive. The disease affected the people in age group 20-50 years. The investigating
NICD team suggested that the man made ecoenvironmental disturbances like creation of
bunds, construction of houses in continuous fashion, construction of roads with
inadequate drainage system and discontinuation of water transport system might have
contributed to water logging condition thus contributing to the increase in Leptospirosis
in the state.[24]
Prevention strategies of human leptospirosis include wearing protective clothing for
people at occupational risk and avoidance of swimming in water that may be
contaminated. Leptospirosis control in animals is dependent on the serovar and animal
species but may be either vaccination, a testing a culling programme, rodent control or a
combination of these strategies. [25]
3.6.2 Cholera:
Cholera Known as one of indicators of public health status of any community. Cholera is
caused by a bacteria and it is transmitted trough drinking water. This causes severe
diarrhoea and often death. This is one of the few notifiable diseases identified by world
health organisation. Though the reported incidence of cholera is very less in the state yet
many out breaks has been documented in the state in recent times. The reported colera
cases has been linked to the monsson pattern in the state
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Source: CBHI India. http://www.cbhidghs.nic.in/hii2003/10.02-1.htm
Figure-3.15: Reported cases of Cholera in Kerala-2002
The figure 3.15 shows the reported cases of cholera in Kerala In the year 2002 with
two peaks April- June at the beginning of monsoon and October- December , at the
end of the monsoon. [26]
Wide-spread outbreak of cholera occurred in Alappuza district during January to
March, 2000. Cherthela south panchayat reported outbreak of cholera during
January with 6 culture positive cases with no death. One culture positive case was
reported during the outbreak in Nulamperoor. Death was not reported. [27]
3.6.3 Mineral water industry
This is one of India's fastest growing industrial sectors [28]. The all-India market for
packaged water is between Rs. 8 billion and Rs. 10 billion and is growing at the rate
of nearly 40 per cent per annum. The ubiquitous bottled water is a common sight
even in the remote villages of India. This signals the low confidence of the public in
the safety of their water supply. People in many states depend on packaged water to
mitigate the acute shortage of drinking water. Water vendors are also common in
India, especially in the unserved areas of water-short cities. Such privately vended
water - which seldom has any quality controls, sells for from 5 to 50 times the price
of piped city-supplied water [3]. For example, water-starved people of Chennai have
paid nearly Rs. 500 million to private water
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31/3/2005. Kerala Water Authority.
Source:DHS
Data source: District-wise population covered by Water Supply Schemes as on
Figure-3.16: Relationship between water supply and diarrheal cases
companies for 3.7 billion liters of potable water each month to augment the inadequate
supply delivered by the state-run MetroWater. There are several water packaging units
(approximately 200 legal and 400 illegal) in the city which sink powerful pumps in small
plots of land, in effect privatizing entire aquifers of common groundwater resources.
Several million litres of precious water get wasted in the process. Even the conservative
figures declared by the industry indicate that packaged water units waste anywhere
between 15 and 35 percent of the water they draw from the ground [29].
3.7 RESPONSE
3.7.1 Institutional arrangements
The government has taken several steps to mount a positive response like: ENVIS, Swajal
Dhara, Total sanitation campaign, Integrated disease surveillance project
National Vector Borne disease control programme, National Water Policy 2002, National
Health Policy, Population based surveillance system to monitor water contaminants.
Inadequate vector control measures and a lack of coordination between various
stakeholders has resulted in ineffective and a negative response.
Department of Drinking Water Supply (DDWS) is the nodal department in the Ministry of
Rural Development (MoRD) ,Government of India, providing scientific and technical
assistance to the states in drinking water and sanitation sector. A major intervention in
water sector started in 1972-73 through 'Accelerated Rural Water Supply Programme'.
New initiatives in water sector had been initiated through Sector Reform Project later
scaled up as Swajaldhara in 2002. In sanitation sector,Central Rural Sanitation
programme, which was introduced in 1986, had been restructured,and Total Sanitation
Campaign was launched in 1999 with people centered, and demand driven approach [30].
In-land water quality monitoring in India is conducted at 480 stations under the following
two programmes:
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" Global Environment Monitoring System (GEMS); and
" Monitoring of Indian National Aquatic Resources (MINARS)
The Water Quality Monitoring network covers 126 rivers, wells, lakes, creeks, ponds,
tanks, drains and canals. Monitoring of the rivers in North Western Region and a few
lakes wells are conducted on a quarterly basis and at all the other locations on a monthly
basis. Measurements are made for 25 physico-chemical and biological parameters [31].
3.7.2 Infrastructure and Legislative measures
India is a party to the UN Conference on Environment and Development (UNCED) held
in 1992. In the same year, a national conservation strategy and a policy statement on
environment were formulated. The policy addresses issues related to sustainable
development including health. Thrust has also been given to management of hazardous
waste, adoption of clean technologies by industries, establishment of effluent treatment
plants, criteria for environmentally friendly products, phasing out of ozone depleting
substances, and creating mass awareness programmes. There are many constitutional
provisions and laws pertaining to the environment and its protection and improvement.
However, the level of enforcement has been extremely poor. Besides, there is no
comprehensive legislation on environment and health. In view of the current situation and
the Dayal Committee Report, it was proposed that action be taken by the concerned
ministries/departments to prioritize the areas and activities that should be included in the
9th plan. During the 9th Five year Plan, the Ministry has proposed the following
actions.[32]
3.7.3 Research studies undertaken and projects initiated
A number of individual research studies have been undertaken in the area of
environmental health. But the access to these is severely limited. In addition, several
projects coordinated by the government are in progress. The Environment Management
Plan under the Integrated Disease Surveillance Project was drafted with the objective of
providing specific timely information on selected priority health conditions and risk
factors, so that preventive and control measures can be planned and implemented.
Importance was given to food and drug testing labs and to comprehensive waste
management from source to disposal, to prevent adverse impacts on the environment and
public health [33].
The Kerala Rural Water Supply and Environmental Sanitation Project was started with
the objective of improving the quality of water supply and sanitation. This was done
mainly by implementing new decentralized service models and improving sector
management capacity [34].
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3.7.4 Policy and practice
The government is realising the importance of environmental effects on health. The 2002
National Water Policy of the Government of India, Sections 6.1, 8, states that "provision
for drinking water should be a primary consideration" in water resource development
projects and that "drinking water needs of human beings and animals should be the first
charge on any available water". It is commendable that online forms, guidelines, some of
the data and policies are available on dedicated web-sites. Unfortunately, there is no
single governmental organisation solely responsible for looking at environmental health
issues. There are multiple regulatory authorities and a plethora of laws.
Environmental health is grossly neglected in the medical curricula, and there is almost
never a continuing medical education programme in this field. There is also considerable
ignorance among the general public concerning health effects of environmental agents.
This is compounded by areas of uncertainty in information flow across government
institutions and departments that are dealing, albeit indirectly, with environmental health.
People's force- Temple ponds without proper flushing mechanism can easily turn into a
stagnant water body and a perfect breeding centre for mosquitoes. Repeated complaints
and pressure from local residents of some areas has compelled the relevant authorities to
at least investigate, even if it does not lead to action [35].
3.8. Limitation of data
Most of the data analysed and presented here is from governmental agencies. Data from
private hospitals was not accessible. There is also no break up of data in different groups
like male/female, child/adult or rural/urban. This limitation is relevant here because most
cases of diarrhoea are expected to affect the paediatric age group, which is not reflected
in this report because such data is not recorded.
3.9. Conclusions
Based on the findings, it is evident that water borne and vector borne diseases contribute
to a major share of communicable diseases in Kerala. There is a definite correlation
between access to safe drinking water and outbreak of water borne diseases.
Unfortunately, the information exchanged within and between departments is severely
limited. Risk assessment is therefore not thorough because age and sex disaggregated data
is not available. Environmental health issues are neglected in medical curricula and
awareness about environmental health among the general public and health professionals
is generally poor. Resources on the earth are not unlimited. Clean up of the environment
is expensive and time and effort intensive. Protection of the environment and preservation
of ecosystems are the most fundamental steps in preventing human illness. Unless some
drastic measures are undertaken by the government, it could have disastrous consequences
on our health.
3.10. Recommendations:
i. Data standards and sharing- Data from various Government departments that is
available on a regular basis (from Kerala water authority, Kerala pollution control Board,
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meteorological department, tourism department, census, department of economics and
statistics, disaster management and health department etc) should be standardised.
Institutional mechanisms for getting primary data, for developing lateral linkages and for
sharing the information should be urgently developed. The use of GRID computing for
sharing and analysis of data can be cost effective and time saving, as has already been
demonstrated by National Environmental Health Services, US.
ii. Research-The available and on going research projects in various educational
institutions like Medical colleges, Agriculture University, Government research labs, etc
are an excellent source of data. A repository of scientific publications from these
education institutions can provide vital information about the effect of environment on
health. Though ENVIS is a good first attempt, more needs to be done.
iii. Training- Sustained training programs in environmental health for physicians, public
health professionals, engineers and technical people working on floor shops should be
conducted regularly to prevent negligence arising from ignorance. Sensitization to
environmental issues should be started in the school curriculum and sufficient emphasis
should be laid in the medical curricula as well.
iv. Surveillance- Environmental health surveillance with population-at- risk approach (For
example monitoring lead pollution levels near traffic stands, conducting biomedical
examination of traffic police personnel and near by shop keepers)
and Mathematical modeling for predicting future changes in risk factors and its effect on
health should be seriously considered. In view of the increasing problem of water quality
and the resultant health hazards, it is necessary to institutionalize water quality monitoring
and surveillance systems. Water quality surveillance should be done by an independent
organization.
v. Infrastructure-Sate level accredited laboratories for detecting environmental effects should
be established. These laboratories should not only help other institutions build their research
capacity, but also routinely undertake investigations to find out the linkages between various
environmental hazards and health, and also should provide early warning information to the
state and to the public.
vi. Forum for interaction-As citizens are the ones most affected by the changing
environment, a forum for citizens, Non Governmental Organizations, scientists, legislators
and administrators should be developed for interaction and timely announcements. The use
of available information technology tools will be immensely helpful for this.
References
1. Kerala Water Authority. Available from http://keralawater.org/policy.htm
2. Last, J. M. (Ed.). (1995). A Dictionary of Epidemiology (3rd ed.). New York: Oxford
University Press.
3. David McKenzie, Isha Ray. Household water delivery options in urban and rural India.
Paper prepared for The 5th Stanford Conference on Indian Economic Development, June
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3-5, 2004
4. Water quality in India: status and trends 1990-2001. Central Pollution control board,
Ministry of Environment and forests
5. Ramaswamy R. Iyer. Water: Charting a course for the future July-august 2000. Back
ground paper vision 2020]
6. WHO. SEARO. Health and environment. Country Health Profile: India. Page 4-5
Available from http://www.searo.who.int/LinkFiles/India_india.pdf
7.
Centers
for
disease
http://www.cdc.gov/ncidod/dbmd/diseaseinfo/waterbornediseases_t.htm
control
8. Guidelines for drinking-water quality, third edition, Ch 5 Surveillance:pg 91
World Health Organization 2006
9. Water Resources. Economic Review. Kerala Planning board. 2005. Givernment of Kerala
page- 144-178]
10. Kerala Environmental Congress 2005: Proceedings. `Risk assesment of diarrheal
serotypes of E.Coli from cchin estuary' Mujeeb Rahiman KM, Harsha HT and Hatha AAM
11. Groundwater arsenic contamination in West Bengal - India (19 years study)
http://www.soesju.org/arsenic/wb.htm
12. K.Park. Environment and Health. Park's Text boom of Preventive and Social Medicine.
16th Edition
13. Kerala. List of Quality affected by Vegetations. National Habitation Survey
2003.Department of drinking water supply.Ministry of rural development. Government of
India.
14. Gopalakrishnan P, Vasan RS, Sarma PS, Nair KS, Thankappan KR. Natl Med J India.
1999 May-Jun;12(3):99-103
15. WHO. Acceptability aspects. Guidelines for Drinking-water Quality . Third Edition.
2004
16. Sunil Kumar Gupta R. C Gupta , A. K Seth, A. B Gupta. J. K Bassin B.E, D. K Gupta ,
Susheela Sharma . Epidemiological evaluation of recurrent stomatitis, nitrates in drinking
water, and cytochrome b5 reductase activity .The American Journal of Gastroenterology 94
(7), 1808_1812.
17. Health and Development in Rural Kerala. KP Kanna, KR Thankappan, V Ramankutty,
KP Aravindan, Kerala Sasta Sahitya Parisad. 1991, T. P. Kunhikannan, K. P. Aravindan
Changes in the Health Status of Kerala 1987 to 1997. Discussion Paper No. 20. June
2000.Kerala Research Programme on Local Level Development . Centre for Development
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Studies. Thiruvananthapuram
18. World Health Organisation http://w3.whosea.org/cntryhealth/india/indenviron.htm
19. http://www.who.int/water_sanitation_health/diseases/leptospirosis/en/
20. Leptospirosis worldwide, 1999. Weekly epidemiological record published by WHO(
1999, 74, 237-244]
21. Kuriakose M, Eapen CK, Paul R. Leptospirosis in Kolenchery, Kerala, India:
epidemiology, prevalent local serogroups and serovars and a new serovar. Eur J Epidemiol.
1997 Sep;13(6):691-7
22. Outbreak 2000 http://nicd.org/investreports/2000.09.leptoje.asp]
23. Upsurge in the incidence of Leptospirosis in Kerala. RMRC Port Blair.
http://www.icmr.nic.in/rmrcpb/links/out/kerala.htm
24. Epidemiological investigation of Leptospirosis in Kerala State, (21-24 September
invetigation
report
september
2002
2002).
NICD.
http://nicd.org/investreports/InvestSep2002.asp
25. http://www.who.int/zoonoses/diseases/leptospirosis/en/
26. http://www.cbhidghs.nic.in/hii2003/10.02-1.htm
27. NICD. allpaluzha http://nicd.org/alappuzah.asp]
28. Bottled loot Chandra Bhushan.The structure and economics of the Indian bottled water
industry. FrontlineVolume 23 - Issue 07 :: Apr. 08 - 21, 2006.
29. http://www.indiaresource.org/issues/water/2003/waterprofiteers.html
30. Department of Drinking Water Supply, Government of India.
http;//www.ddws.nic.in/index.html
31. http://envfor.nic.in/cpsb/intro.html
32. World Health Organisation
http://w3.whosea.org/cntryhealth/india/indenviron.htm )
33. Health related activities of Ministry of Health, Government of India.
Http://mohfw.nic.in/depth.htm
34. World Bank http://web.worldbank.org/external/projects/main?
36. (http://www.hindu.com/2006/08/01/stories/2006080121810300.htm)
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Case study of mosquito borne diseases in Kerala
3a) Introduction
Mosquito-borne diseases contribute substantially to the disease burden, in terms of
morbidity and mortality. Human beings act as both host and reservoir of the disease.
These diseases are transmitted when a mosquito bites an infected person. Among the
factors that facilitate the transmission of the mosquito borne diseases, environmental
factors like rainfall, high population density, rapid urbanisation and improper water and
waste management are of importance [1] Malaria remains a high priority in Indian context
because of its high mortality rate. Various control measures have been initiated over the
last several decades with only partial success. Reported annual number of Malaria cases
in India was around 220000 per year in 1998 to 180000 in 2005 [2][3]. Though the burden
of Malaria in the state of Kerala is relatively low, the recent emergence of Dengue,
Japanese Encephalitis (JE) and re-emergence of Chikungunya as major public health
problems in the state made it necessary to write a separate chapter on mosquito-borne
disease in the state.
3b) Scope
Though there are several mosquito-borne diseases, our chapter will focus only on Malaria,
Filaria, Japanese Encephalitis, Dengue and Chikungunya. The discussion will follow the
Driving force, Pressure, State, Impact, Response (DPSIR) framework.
The data was collected from publications of (1) Directorate of Health Services- Kerala,
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(2) National Vector Borne Disease Control Program-India, (3) World Health organisation
and (4) published articles in international and national journals.
3c) Flow of Information related to mosquito borne diseases:
Although the responsibility of implementing and monitoring the National disease control
programme lies with the state government, there is a system of co-ordination between the
state and the centre for effective implementation and monitoring of programmes.
3d) Surveillance:
Active surveillance is carried out by health workers fortnightly in every sub centre. There
are 5094 sub-centres which are the village level health institutions for delivery of primary
health care [4]. The reporting chain is from sub centres to the Primary Health Centres to
Community Health Centres- to Taluk hospitals to District hospital to Directorate of
Health services. Passive surveillance for mosquito borne diseases is carried out by
Primary Health Centres (PHCs), Community Health Centres (CHC) and other secondary
and tertiary level health institutions like Taluk hospitals, District hospitals and Medical
College hospitals which patients visit for treatment. At the district level, District Malaria
Offices have been established in each district under district chief medical officers of the
state. This is the key unit for planning and monitoring of the programme, under a
technical officer.
The climatic condition in Kerala- high rain fall, temperature around 30 C, high vegetation
and large amount of slow moving or stagnant water bodies, wells, lakes, ponds are
suitable for breeding of mosquitoes. The high density of population with lack of personal
protection measures makes it easier for the disease to be transmitted to human beings
through mosquito bite. In addition, rapid urbanisation has lead to many overhead tankers
(many are not covered), use of plastic bottles, cups, tires that act as suitable breeding sites
for many mosquitoes. Another site of stagnant water is rice cultivation sites and rubber
plantation sites, where the stagnant water provides conducive environment for the
mosquitoes to breed.
High health seeking behaviour of the people of the state has stretched the public health
system making the preventive efforts inadequate. Though most of the mosquito control
measures can be taken up by individuals, the absolute lack of concern for the environment
has resulted in increase in mosquito born disease in the state.
Well-established diseases like Filarial and Malaria are yet to be eliminated. Diseases like
Dengue and Japanese Encephalitis, which were rare two decades ago, are now reported
every year. With lack of primary reporting from private hospitals, the actual burden in
difficult to estimate. The Chikungunya epidemic in 2006 is a sign of re emergence of
diseases among the population.
The National Vector Borne Disease Control Program is a combination of all the effort in
relation to prevention, control and treatment of mosquito borne diseases in the country
and the state. However this program is limited by a low level of community participation
and implementation of program mainly through public health sector. While private health
sector plays a major role in providing curative health care, their involvement in preventive
and promotive health care is limited. In addition, the routine reporting of vector borne
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diseases from private sector is almost negligible. In order to address these issues, the
Integrated Disease Surveillance Program has been initiated in the state.
Figure-3.6: Mosquito borne diseases and Human health in DPSIR framework
Driving forces responsible for vector borne diseases are described in the next section in
detail.
3e) DRIVING FORCE:
As discussed earlier, the major driving forces for emergence and re- emergence of vector
born diseases can be attributed to the high population density, rapid and spreading
urbanisation , increase in human demand for limited space and resources, lack of early
warning measures for vector borne diseases, and a lack of concern for environmental
issues. Global warming and climate change is predicted to have an effect in the form of
increase in mosquitogenic activities by year 2050 and increase in Malaria disease burden.
In Kerala, the main reason for urban population growth is the increase in the number of
urban areas and also urbanisation of the peripheral areas of the existing major urban
centres [5]. The Urban growth from the year 1981, there were 106 census towns to 197
towns in 1991, with population growth from 18.74 percent of the total population to 26.44
percent of the total population during this time [6]. It is predicted that the urban
population will grow from 26.0% of total population in the year 2001 to 30.3% of total
population in the
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year 2026 [7]. A rapid rise in urban populations is bringing ever greater numbers of
people into contact with this vector, especially in areas that are favourable for mosquito
breeding, e.g. where household water storage is common and where solid waste disposal
services are inadequate [8].
The population density in kerala has increased from 749 per square kilometre in the year
1991 to 819 per square kilometre in the year 2001, where as the population density in the
country has increased from 267 per square kilometre to 324 per square kilometre during
this period [9]. This high population density creates challenges for the Public Health
authority to provide a healthy environment.
These driving forces exert pressure on the environment, which leads to proliferation of
mosquitoes and spread of the diseases. Pressure on environment is elaborated in the next
section.
3f) PRESSURE:
High population density, humidity, warm temperature and lack of concern for
environmental issues creates the enabling environment, like water storage tankers, pot
holes, for the mosquitoes to breed and infect people rapidly. The dependence on National
Vector Borne Disease Control Program has resulted in low level of involvement of other
stake holders and promotion of local initiatives. In addition, rapid unplanned urbanisation
has lead to mushrooming of overhead tankers (many are not covered) and inadequate
waste collection and disposal system (like the use of plastic bottles, cups and tires) that
act as suitable breeding sites for many mosquitoes. Stagnant water in rice cultivation sites
and rubber plantation areas provides conducive environment for the mosquitoes to breed
freely. Lack of awareness among the farmers about the control measures for mosquito
born diseases has lead to lack of adequate control measures.
Lack of coordination between various stakeholders involved in health care (both private
and public), environmental agencies and research organization has resulted in ineffective
preventive measures. The over burdened public health care and the almost non
involvement of private health sector (which is the major health care service provider) in
preventive services has resulted in providing curative services mostly, which is reflected
in low death rates. Also, the public health system is providing preventive services with
only a limited impact.
3g) STATE:
The evidence for the emerging mosquitogenic conditions is evident from the
entomological surveys undertaken at the international airports/seaports during 1998-2004
where high vector indices of dengue was found around Trivandrum Air port area [10][11].
Anopheles culicifacies is the main vector of Malaria which breeds in rainwater pools,
puddles, borrow pits, river bed pools, irrigation channels, seepages, rice fields, wells,
pond
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margins, sluggish streams with sandy margins. Extensive breeding is generally
encountered following monsoon rains. Kerala is a state with 47 rivers, hundreds of wells,
and several hectares of rice fields. This, together with a high amount of rainfall provides a
suitable environment for mosquitoes to breed.
The virus causing Japanese Encephalitis (JE) is transmitted by mosquitoes belonging to
the Culex tritaeniorhynchus and Culex vishnui groups, which breed particularly in
flooded rice fields. In a 2 year entomological study in Kerala, it was found that Culex
tritaeniorhynchus Giles (66.7%) was the most abundant species, with increases in
numbers associated with rice cultivation. JE virus isolations were also made from Cx.
tritaeniorhynchus and Mansonia indiana Edwards [12]. JE causes severe epidemics which
are highly seasonal, occurring during the monsoon season when temperatures reach 30 °C
or above and [13]. The average temperature in Kerala is around 30 °C, and that provides a
conducive natural environment for the Culex mosquito to breed and grow. Out of the 13
identified species of mosquitoes that transmit JE, five have been found to carry the
disease in Kerala. They are Cx. tritaeniorhynchus , An. subpictus , Ma. annulifera , Ma.
indiana , Ma. Uniformis [14].
High annual rain falls; population density and urbanisation are found to be associated
with a high dengue caseload. In countries like Indonesia, Myanmar, Thailand and
Timor-Leste, where dengue is known to be endemic, the annual rainfall in this zone is
>150 cm. The annual rainfall in Kerala is 270 cm (2742 mm) which makes the state
vulnerable to spread of dengue [15]. Aedes aegypti is also responsible for Chikungunya
fever. Aedes aegypti is widespread in both urban and rural areas [16].
Unlike other mosquito borne diseases discussed here, Filaria does not manifest as acute
illness. In Kerala the overall reduction in the prevalence of micro filarial cases and vector
infection rates over the years can be attributed to the drastic reduction in the
Mansonioides breeding habitats, with improved socio economic conditions and high
health seeking behaviour of the community. Any case of fever of unknown origin was
treated with the drug DEC and a course of antibiotics. This is probably the reason why
with other conditions remaining constant, the microfilarial index came down, although
endemicity did not.
Prevention is the only mode of reducing vector borne diseases, with personal protection
and environmental protection systems. With these preventive measures falling, the burden
of mosquito borne disease is on rise in the state. This impact of falling preventive
measures is discussed in the following section.
3h) IMPACT:
i) MALARIA
Malaria is a common disease of the tropical world caused by the parasite Plasmodium.
The disease is transmitted from man to man by the infective bites of female mosquitoes
belonging to genus Anopheles, as the mouth parts of male mosquitoes are not developed
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for biting and cannot pierce the skin. There are 4 species of malaria parasites, of which 3
species are found in India. These are:
Malaria in India:
The country's 95% population lives in malaria risk areas. In most parts of India, about
90% malaria is unstable with relatively low incidence but with a risk of epidemics every 7
to 10 or more years. This depends on the immune status of the population and the
breeding potential of the mosquitoes, rainfall being the leading cause of malaria
epidemics as it creates a high mosquito population. India has been able to contain malaria
incidence to between 2 and 2.5 million cases annually for more than a decade in spite of
increased population at rate of 2.1% annually [17].
Malaria in Kerala:
The reported malaria cases in Kerala have declined from 3300 in the year 2002 to 2121 in
2005 [18]. The proportion of cases in comparison to the national average of 1.8 million
cases every year is very small [17].
(Source: DHS, Kerala)
While the proportion of cases was highest in Kasargod, Pattanmthitta and Trivandrum has
also shown high proportion of reported Malaria cases figure 3.7. Except Kasargod, the
Figure-3.7: District wise reported malaria cases in Kerala 2004 and 2005.
proportion of cases increased with an increase in population density and the proportion of
cases from five Northern districts (Kasargod, Kannur, Wyanad and KozhiKode) were
more in comparison to five Southern districts ( Trivandrum, Kollam, Pathanamthitta,
Apllapuzha and Kottayam). Though the Malaria caseload is less in the state, it provides us
the valuable information about which are the potential areas for future emphasis of public
health programmes. In a research paper Bahatcharya S et al has predicated that by the year
2050 malaria might shift from the central India to other states like Kerala due to climate
change [19].
ii) JAPANESE ENCEPHALITIS
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Japanese encephalitis (JE) is a viral disease that infects animals and humans. It is
transmitted by mosquitoes and in humans, causes inflammation of the membranes around
the brain. Most JE virus infections are mild (fever and headache) or without apparent
symptoms, but approximately 1 in 200 infections results in severe disease characterized
by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures,
spastic paralysis and death. The case fatality rate can be as high as 60% among those with
disease symptoms. 30% of those who survive suffer from damage to the central nervous
system. In areas where the JE virus is common, encephalitis occurs mainly in young
children because older children and adults have already been infected and are thus
immune [20].
JE in India:
JE viral activity has been widespread in India. The first JE case was reported in 1955.
Since then, outbreaks have been reported from different parts of the country. During the
recent past (1998-2004), 15 states and Union Territories have reported JE incidence
Annual incidence ranged between 1714 and 6594 and deaths between 367 and 1665 [21].
The figure 3.8 shows the reported number of Japanese encephalitis cases in Kerala during
the year 2001 to 2004.
Though the over all burden of disease is declining in Kerala over time, the disease has
been reported from almost all the districts of the state. The high case fatality and
morbidity associated with the disease warrants necessary steps to be taken to eliminate the
disease from the state. In a study conducted in Uttar pradesh, which is one of the states
hardest hit by JE, a bimodal pattern with short and tall peaks during March and September
respectively were noticed. Based on the elevated density and infection with JE virus
where Culex tritaeniorhynchus has been considered the major cause of epidemics, it has
been linked to paddy cultivation in Kerala [12].
(Source: National Vector Borne Disease Control Programme)
Figure-3.8: Reported JE cases in Kerala in comparison to India: 2001-2004.
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JE vaccine is produced in limited quantities at the Central Research Institute, Kasauli.
Three doses of the vaccine provide immunity lasting a few years. The vaccine is procured
directly by the state health authorities. Vaccination is not recommended as an outbreak
control measure as it takes at least one month after second dose to develop antibodies at
protective levels and the outbreaks are usually short lived. Arial or ground fogging with
ultra low volume insecticides can be an effective method. All villages reporting dengue
cases should be brought under residual spraying of houses, surrounding vegetation and
animal shelters [22].
iii) FILARIASIS
Lymphatic filariasis is estimated to be one of the leading causes of disability worldwide is
caused by round thread-like parasitic worms either Wuchereria bancrofti or Brugia malayi
and transmitted by mosquito species Culex quinquefasciatus and Mansonia
annulifera/M.uniformis respectively. The disease was recorded in India as early as 6th
century B.C. by the famous Indian physician, Susruta in his book 'Susruta Samhita'.
Figure-3.9: Micro filarial rate in Calicut :
Table-3.6: Trend and Present Endemicity of the Problem India and Kerala. Year
2002.
These parasites after getting deposited on skin penetrate on their own or through the
opening created by mosquito bites to reach the lymphatic system. The disease manifests
often as swelling of legs, and hydrocele, and is the cause of a great deal of social stigma.
The adult filaria produces millions of very small immature larvae known as microfilariae.
The worms usually live and produce microfilariae for 5-8 years. Elimination of the
disease is an important tool for poverty alleviation and economic development. Filariasis
has been a major Public Health problem in India next only to malaria.
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In India, 99.4% of the cases are caused by the species - Wuchereria bancrofti whereas
Brugia malayi is responsible for 0.6% of the problem. W.bancrofi infection has been
showing
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develops immunity to this single serotype. Upon second infection with a different
serotype, the patient stands a greater risk of developing dengue haemorrhagic fever
(DHF), a more serious and potentially fatal disease. DHF is characterized by high fever,
haemorrhagic phenomena, enlarged liver and circulatory failure. The patient may recover
and symptoms abate. But if left untreated, the patient may go into shock (DSS) and
without proper treatment, the patient may die within 12-24 hours. The risk of DHF is
approximately 0.2% during the first dengue infection but increases 10-fold during
infection with a second serotype of dengue virus [27]. The principal vector is Aedes
aegypti. Once infected, a mosquito remains infective for life. Infected humans circulate
the virus in their blood, mosquitoes ingesting viruses when feeding on the infective
individual. Humans serve as an amplifying host [28]. Female mosquitoes can also
transmit the virus transovarially, passing it down to the next generation. Transovarial
dengue infection in Ae. aegypti larvae appeared to maintain or enhance the epidemics
[29].
Dengue in India:
The disease tends to follow seasonal pattern, i.e., the cases peaking after monsoon and it
is not uniformly distributed. First outbreak was reported during 1963 in Kolkata. The next
major outbreak of Dengue/Dengue Haemorrhagic Fever was reported in Delhi and
neighbouring states in 1996. Following this outbreak, the reporting of dengue fever was
made mandatory to ensure early preventive measures in case of outbreak. Out of 18
endemic states/UTs, the most affected states are Delhi, West Bengal, Kerala, Tamil Nadu,
Karnataka, Maharashtra, Rajasthan, Gujarat and Haryana. Apart from Delhi, up to
November 2006, the maximum number of dengue cases have been reported from
Rajasthan (1224), followed by Punjab (931), Kerala (880), West Bengal (975), Uttar
Pradesh (631), Maharashtra (593), Gujarat (503), Haryana (450), Tamil Nadu (328),
Andhra Pradesh (150) and Karnataka (98) [30].
Dengue in Kerala:
The trend of Dengue/DHF since 2001 in India and Kerala is depicted in the graph below:
(Source NVBDCP http://www.nvbdcp.gov.in/dengueC&D.html )
The trend of dengue in Kerala in comparison to India during 2001 to 2005 shows that
dengue cases in the state was highest during the year 2003 and after that there is a
reduction in number of c reported cases.
The reported dengue cases emerged in the year 2001 with Ernakulum, Idduki and
Kottayam as the first report such cases. In subsequent years the disease spread to 12
districts and by 2003, the state saw an outbreak of dengue with more than 3800 cases
reported from al the districts. Though a decline in reported dengue cases is noticed in
2004 and 2005 the diseases were reported from all the districts. It is important to notice
that
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Figure-3.10: Reported dengue cases in India and Kerala: 2001-2005
the state with 3% of total population is contributing to more than 8% of Dengue cases for
the last five years, every year. Research studies from Kerala has shown that dengue is
associated with rubber plantation where clean water gets stagnated in the containers
attached to the rubber plants, thus making it a suitable breeding place for the mosquito
[31]. Similarly another study from Ernakulam concluded that improper disposal of plastic
cups provides suitable breeding places for Ades mosquito [32].
v) CHIKUNGUNYA
Chikungunya fever is a self limiting, preventable viral disease transmitted to humans by
the bite of infected mosquitoes. The term 'Chikungunya' in Swahili language stands for
'that which bends up.' The first recognized outbreak occurred in East Africa in 1952-1953.
Chikungunya is spread by the bite of an Aedes mosquito, primarily Aedes aegypti.
Humans are thought to be the major reservoir of Chikungunya virus for mosquitoes.
Therefore, the mosquito usually transmits the disease by biting an infected person and
then by biting someone else. An infected person cannot spread the infection directly to
other persons (i.e. it is not a contagious disease). Aedes aegypti mosquitoes bite during
the day time. The time between the bite of a mosquito carrying Chikungunya virus and the
start of symptoms ranges from 1 to 12 days. Chikungunya is diagnosed by blood tests
(ELISA). Since the clinical appearance of both Chikungunya and dengue are similar,
laboratory confirmation is important especially in areas where dengue is present.
Experimental data raised using this test showed that trans-ovarial transmission of this
virus does not occur in these vector species [33].
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Chikungunya in India:
In India a major epidemic of Chikungunya fever was reported during the last millennium
i.e; 1963 (Kolkata), 1965 ( Pondicherry and Chennai in Tamil Nadu, Andhra Pradesh;
Madhya Pradesh; and Maharashtra) and 1973, (Barsi in Maharashtra ). Thereafter,
sporadic cases also continued to be recorded especially in Maharasthra during 1983 and
2000 [34]. A mixed outbreak of Chikungunya with Dengue had been reported in Andhra
Pradesh between 1st December 2005 - 17th February 2006, 5671 cases of fever with joint
pain were reported. High density of Aedes aegypti was observed in the area. From 1st to
15th March, over 2000 cases of Chikungunya have been reported from Malegaon town in
Nasik district, Maharashtra [35].
Chikungunya in Kerala:
Since May-June 2006, Kerala has reported outbreaks of Chikungunya in some localities
of Kozhikode, Trivandrum, Ernakulam and Alappuzha districts (table 3.7). These four
districts have highest population density in Kerala. The reported population density of
Trivandrum, Kozhikode, Ernakulum and Alapuzha are 1476, 1498, 1050 and 1228
persons per square Kilometre in the year 2001[41]. Community surveys revealed very high
indices of aedes breeding (House Index ranging from 21.7% to 57.8%) including in areas
where the attack rate of illness (fever with joint pain) is not high presently [36].
(Source: Chikungunya situation in India (As on 21.11.2006). National Vector Borne
Disease Control Programme GoI.) [37]
3i) RESPONSE:
The Government of India is a signatory to the UN resolution to eliminate lymphatic
filariasis by 2020. The National Health Policy (NHP), 2002 envisages the elimination of
lymphatic filariasis by 2015 [38]. In order to achieve this goal and to reduce the burden of
mosquito borne disease in the state the following measures are available:
1. Mosquito control measures:
The burden of Malaria and JE is less in the state. None the less there is no place for
complacency, as Malaria Eradication Programme four decades ago due to various reasons
saw resurgence of malaria from virtual elimination of malaria deaths in the country [39].
Vector Control By use of Indoor Residual Spray (IRS) with insecticides recommended
under the National Vector Borne Disease Control Programme. Use of chemical larvicides
like Abate in potable water during day time and Malathion fogging during outbreaks can
be useful methods. However, increasing pesticide resistance (especially to synthetic
pyrethroids) of Aedes aegypti remains a concern [40].
Table-3.7: Chikungunya Fever Situation in India and Kerala during 2006
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Biological Control through the use of larvivorous fish in pond, ornamental tanks,
fountains etc. Integrated antilarval measures before the beginning of paddy irrigation may
check the breeding of JE vectors in the rice fields. It may prove beneficial in reducing the
vector population during the JE transmission season. There is no replacement for Personal
prophylactic measures that individuals/communities can use: mosquito repellent creams,
liquids, coils, mats, wire mesh window screens, bed nets treated with insecticide, etc.
Community participation- Sensitizing and involving the community for detection of
Anopheles, Culex and Ades breeding places and their elimination by source reduction i.e.
filling of the breeding places, by not allowing the storage of water for more than a week.
Community-based clean-up campaigns remove desert coolers, drums, jars, pots, buckets,
flower vases, plant saucers, tanks, cisterns, bottles, tins, tyres, roof gutters, refrigerator
drip pans, cement blocks, cemetery urns, bamboo stumps, coconut shells, tree holes and
other items that catch and retain water, eliminating potential breeding sites for vector
mosquitoes. Larval habitats should also treated with insecticide.
2. Medicated salts:
Medicated salt regimens for controlling filarial in India during 1968-69 showed very
encouraging results in pilot trials in Uttar Pradesh and Andhra Pradesh. The distribution
of 0.1% DEC medicated salt to general public for one year was implemented in
Lakshadweep in 1997-77 and in with 0.2% concentration was concluded at Karaikal,
Pond cherry which gave more than 80% 98% reduction in mf. Integrated vector control
approach for control of this infection is being implemented by VCRC Pondicherry in
Shertally Taluk of Ernakulum district, Kerala [41].
3. Legislative Measures
According to the available guideline suitable laws and bye laws should be enacted and
implemented for regulating storage/utilisation of water by communities, various agencies
and avoidance of mosquitogenic conditions at construction sites, factories [42] .
(i) Model civic by-laws: Under this act fine/punishment is imparted, if breeding is
detected. These measures are being strictly enforced by Mumbai, Navi Mumbai,
Chandigarh and Delhi Municipal Corporations.
(ii) Building Construction Regulation Act: Building by-laws should be made for
appropriate overhead / under ground tanks, mosquito proof buildings, designs of
sunshades, porticos, etc for not allowing stagnation of water vis-à-vis breeding of
mosquitoes. In Mumbai, prior to any construction activity, the owners/builders deposit a
fee for controlling mosquitogenic conditions at site by the Municipal Corporation.
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(iii) Environmental Health Act (HIA): Suitable byelaws should be made for the proper
disposal/storage of junk, discarded tins, old tyres and other debris, which can withhold
rain water. This should be enforced effectively with the help of community participation.
Movements like "Clean Kerala" need to be strengthened to reduce the mosquito burden.
The integrated disease surveillance project is designed to collect data from the private
health care providers also. A real-time analysis of the data will be able to provide
information on the hot spots and detect the epidemics at the earliest.
3j) CONCLUSION
The available data from the Directorate of Health Services was analysed, which uses a
fairly well organised system. However, a large proportion of people in Kerala avail
private health services, the data about which is not accessible and hence not reflected
here. Furthermore, there is a mismatch in the published data particularly with reference to
Dengue, between the numbers reported in the state publication (DHS) and that in the
National Vector borne disease control programme. The emergence of dengue and
chikungunya are 'early warning signs' of the degrading environmental conditions. This
also shows the lack of awareness in community about mosquito borne diseases especially
among farmer community for dengue and Japanese Encephalitis. The emergence and
re-emergence of mosquito born diseases indicate the need to strengthen the state disease
surveillance system and develop processes with community participation to prevent these
diseases effectively.
Recommendations and the way forward:
i. Surveillance: There is a need to strengthen the routine surveillance system. As many
affected people are going to private hospitals effort should be made to establish a system
to gather primary data from private health care providers. Routine mapping of mosquito
vectors and parasite indices should be conducted fully utilising the existing laboratory
facilities in the state. Use of GIS based mathematical modelling can help predict and
detect the epidemics in early stages.
ii. Infrastructure-Sate level accredited laboratories for detecting environmental effects should
be established. These laboratories should not only help other institutions build their research
capacity, but also routinely undertake investigations to find out the linkages between various
environmental hazards and health, and also should provide early warning information to the
state and to the public.
iii. Enforcement of environmental laws and incentive mechanisms for communities for
maintaining the environment should be initiated, special effort should be given to the educate
farmers about the mosquito borne diseases.
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