Hydrologic and Geomorphological Assessment of Restoration
Transcription
Hydrologic and Geomorphological Assessment of Restoration
Resource Brief Sky Island Restoration Cooperative Fiscal Year 2015 The Sky Island Restoration Cooperative (SIRC) is a coalition of restoration practitioners, scientists, and land managers, working together to restore the ecological processes and systems of the Sky Islands in the Madrean Archipelago of the US-Mexico Borderlands. Hydrologic and Geomorphological Assessment of Restoration USGS, BLM, Stream Dynamics, Borderlands Restoration, Univ. of Arizona Abstract The USGS and its partners are carrying out assessments of the hydrologic and geomorphological changes induced by streamchannel and riparian restoration at two sites: Vaughn Canyon near Elgin and Silver Creek in the San Bernardino Valley. Preliminary results indicate that site characteristics such as geologic substrate, watershed characteristics, and soil-hydraulic properties must be taken into account during restoration planning, monitoring, and assessment. Keywords Infiltration, geomorphology, geophysics, isotope geochemistry, restoration, monitoring, water and soil detention structures Project Background A number of methods have become available that allow for monitoring and assessment at multiple scales of the hydrologic and geomorphologic changes induced by restoration structures. Measurements of streamflow, soil-moisture, and infiltration are used in conjunction with models to estimate local impacts to the water budget and the response of channel morphology. USGS scientist James Callegary and UA Master’s student Chloe Fandel installing wildlife cameras to track streamflow at Vaughn Canyon, Babocomari Ranch / USGS RTK GPS and terrestrial- LiDAR and drone-based photogrammetry structure from motion (SfM) data to assess geomorphologic changes. The USGS is combining repeat photography, in-channel water stage, and subsurface temperature variation to assess streamflow, and infiltration rates and volumes. We are also using electrical resistance tomography and electromagnetic induction (EMI) to determine subsurface structure and spatiotemporal watercontent variability and isotopic analysis of bed sediments to assess changes in carbon and nitrogen Project Activities and Outcomes cycling and storage. Electromagnetic Induction We report on results from a multidisciplinary, (EMI) can give information on soils, geology, multi-scale approach to assess the interaction of moisture, and salt content as well as information on restoration methods with land management and change in electrical conductivity. This is a simple natural processes at two sites in southeast Arizona and inexpensive way to document that there are (Silver Creek in the San Bernardino Valley, and Vaughn Canyon near Elgin). Local-scale techniques water content changes at depth and to give an approximate depth of percolation. include high-resolution topographic surveys from 45 to landscape characteristics, including geologic substrate, watershed characteristics, and soilhydraulic properties. USGS scientist Tom Porter taking LiDAR measurements at Silver Creek in the San Bernardino Valley / USGS Stream-gaging, and rainfall-runoff and hydraulic modeling are being used to evaluate hydrologic and geomorphologic changes occurring at both local and landscape scales. Preliminary results indicate that methods to support restoration planning, monitoring, and assessment must be tailored not only to the scale, information needs, and scope of the individual project, but also USGS scientists Jeff Cordova and Tom Porter installing a continuous-slope area streamgage at Silver Creek in the San Bernardino Valley / USGS Stakeholder Involvement USGS is coordinating field work with and receives financial assistance from the BLM. BLM also contributed personnel to carrying out geophysical and sUAS surveys at Silver Creek in the San Bernardino Watershed. USGS, with UA professors and students, has installed an infiltration monitoring system in Vaughn Canyon at Babocomari Ranch (discussed in a companion briefing on Vaughn Canyon). UA has also assisted in carrying out geophysical and RTK-GPS surveys. The restoration projects were completed by Borderlands Restoration, BLM, and Stream Dynamics. Funding BLM contributed $100,000 for the Silver Creek project and Walton Foundation (via Borderlands Restoration) contributed as well (funding amount was listed with Babocomari work elsewhere). USGS contributed $40K in-kind. Total project value was approximately $140,000. University of Arizona Professor Ty Ferre augering a hole to assess particle size distribution and hydraulic conductivity in Vaughn Canyon. EMI instrument at left. / USGS Sky Island Restoration Cooperative Multidisciplinary watershed restoration research Editor: James Callegary, Chloe Fandel 46