Brush Management/Water Yield Feasibility Studies for Eight Watersheds in Texas

Abstract

The Soil and Water Assessment Tool (SWAT) model was used to simulate the effects ofbrush removal on water yield in 8 watersheds in Texas for 1960 through 1998. Landsat? satellite imagery was used to classify land use, and the I :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 oflight 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.