Process Based Modeling for Simulating Surface Runoff and Soil Erosion at Watershed Basis

Water Erosion Prediction Project (WEPP), a process based erosion model that computes spatial and temporal distributions of surface runoff, soil loss and sediment deposition from overland flow on hillslopes and soil loss and sediment deposition from concentrated flow in small channels. In the present study, surface runoff and soil loss were simulated in a mini watershed (57 ha) of Sitlarao watershed in hilly terrain using the WEPP watershed model v. 2002.7. Measured surface runoff of mini watershed was validated with WEPP simulated surface runoff for selected rain events. The surface runoff generated for rain events of low to medium rain intensity by WEPP model matched with observation (r = 0.69) while its performance was poor for high rain intensity. Simulated and measured runoff from all the rain events comprising low to high rain intensity showed low regression coefficient (r = 0.25). WEPP model provide explicit spatial and temporal estimate of soil erosion and surface runoff generation of hillslope and in the watershed. Results bring out utility of WEPP model after calibration for soil and water conservation planning at micro / mini watershed level. * Corresponding author.