Brush Management / Water Yield Feasibility Studies for Eight Watersheds in Texas
J. Richard Conner, Joel Bach, Bill Dugas, Ranjan Muttiah, Wesley Rosenthal, Steven Bednarz, Timothy Dybals
This report was published by the Texas Water Resources Institute (TWRI) and the Texas Agricultural Experiment Station Blackland Research and Extension Center at Temple, Texas in conjunction with the Texas A&M University Rangeland Ecology and Management and Agricultural Economics Department. The report was published for the Texas State Soil and Water Convservation Board.
The Soil and Water Assessment Tool (SWAT) model was used to simulate the effects of brush removal on water yield in 8 watersheds in Texas for 1960 through 1998. Landsat7 satellite imagery was used to classify land use, and the 1:24,000 scale digital elevation model (DEM) was used to delineate the watershed boundaries and subbasins. After calibration of SWAT to existing stream gauges, brush removal was simulated by converting all heavy and moderate categories of brush (except oak) to open range (native grass). Treatment or removal of light brush was not simulated. Results of brush treatment in all watersheds are presented. Water yield (surface runoff and base flow) varied by subbasin, but all subbasins showed an increase in water yield as a result of removing brush. Economic and wildlife habitat considerations will impact actual amounts of brush removed.