WATER QUALITY IN THE SIRIRI RIVER BASIN MODELING

INTERNATIONAL CONFERENCE OF AGRICULTURAL ENGINEERING
A g E n g 2 014 Z u r i c h
6 –10 July
WATER QUALITY IN THE SIRIRI RIVER BASIN MODELING
Cristyano Ayres Machado¹; Antenor de Oliveira Aguiar Netto1; Marinoé Gonzaga da Silva1*; Anderson Vasco do Nascimento*1; Ariovaldo Antonio
Tadeu Lucas 1; Inajá Francisco de Sousa1.
1 Department of Development and environment, Federal University of Sergipe, São Cristovão - Sergipe, Postal code: 49100-000, Brazil.
*Corresponding author. E-mail: anderovasco@yahoo.com.br
INTRODUCTION
Water quality depends on natural conditions and use and occupation of
the soil in the basin and their knowledge is essential in water resources
management process. The River Siriri is a tributary of Japaratuba River
Basin the river is an important source of water for human supply and
irrigation, and its main tributaries the Rivers Siriri Vivo and Siriri Morto.
Thus, this study aims to analyze through physical-chemical water quality
the watershed of River Siriri and its seasonal variation parameters. The
monitoring was performed in 7 samples campaigns between February
2010 and November 2011 were evaluated parameters: temperature, pH,
electrical conductivity, color, total dissolved solids, hardness, dissolved
oxygen, ammonia, nitrate, nitrite, total nitrogen phosphate, total
phosphorus and chlorophyll-a.
METODOLOGY
Studied area
The watershed of the River Siriri (Fig. 1) is part of the watershed of the River
Japa-ratuba and is located between the coordinates 10 ° 11 'and 10 ° 49' south
latitude and 36 ° 41 'and 37 ° 26' west longitude, presenting a total area of 433.85
km2. Its main tributary is born in the town of Nossa Senhora do Socorro- SE.The
River Siriri is formed by the junction of the rivers Siriri Vivo, Siriri Morto and Sangradouro, fully supplying the city of Nossa Senhora do Socorro-SE, which has a
population of 24,579 inhabitants.
RESULTS AND DISCUTION
Data analysis of the parameters can be inferred that the river Siriri
Live, SV1 and SV2 stations, presents good quality. Despite the
Siriri river throughout its length be classified as Class 3
freshwater, river Siriri Vivo can be classified in Class 2,
considering the analyzed parameters. However, one should be
concerned with land use, since the primary use is as the
monoculture of sugar cane, the carrying of nutrients from fertilizer
application which can compromise the quality of this water, since
the stations collection located on this river, had the highest
concentrations of nitrate.
The situation of the river Siriri Morto is worrying, since SM1
station receives domestic effluents from the town of Nossa
Senhora do Socorro, thus high levels of dissolved oxygen, which
is an important parameter of water quality, and indicative of good
conditions sanitary were verified , yet these high values were
associated with elevated concentrations of chlorophyll-a, it can be
inferred that this oxygen is originated of algal activity. This fact
associated with higher concentrations of nutrients, indicates
eutrophication of this weir process.
Table 1 - Description of the main parameters of water quality
SM1
SM2
SV1
SV2
Stations
Max
Min
Avg
Max
Min
Avg
Máx
Min
Avg
Max
Min
Avg
pH
8.84
6.91
7.63
7.61
6.36
6.85
6.85
5.15
5.66
7.32
5.26
6.18
EC (µS cm-1)
730.00
312.00
477.60
324.00
136.00
205.77
305.00
109.00
177.07
250.00
114.00
157.24
TDS (mg L-1)
358.00
48.00
186.90
160.00
22.00
74.86
187.00
19.00
81.57
123.00
22.00
70.00
DO (mg L-1)
13.19
4.84
8.00
7.48
4.10
6.32
7.89
5.42
6.84
9.16
4.98
7.11
Ntotal(mg L-1)
44.24
2.68
13.12
7.29
1.22
3.10
11.96
1.98
6.78
8.45
2.12
5.46
Ptotal(mg L-1)
0.10
0.00
0.02
0.29
0.00
0.10
0.08
0.00
0.05
0.03
0.00
0.02
Chl-a (µg L-1)
110.50
0.90
34.86
22.96
1.22
6.87
9.80
1.78
3.42
6.42
0.00
2.34
CONCLUSIONS
Accordingly, for the improvement of water quality of the river Siriri
should seek treat-ment of domestic effluents discharged into the
River Siriri Morto and achieve sustainable land use in this
watershed, in order to minimize impacts on water quality caused
by agricultural activities in the region.
Figure 1: Localization of the River Siriri watershed in Sergipe, Brazil.
Monitoring was conducted in seven quarterly sampling campaigns, from February
2010 to November 2011 in four stations distributed throughout the river basin Siriri
(Table 1). The SM1 and SM2 stations are located in the River Siriri Morto and SV1
and SV2 stations are located in the River Siriri Vivo.
Support: