Temporal Simulation of Sediment Yield Using WEPP Model in Dal Catchment of Temperate Region of Kashmir Valley, India: Case Study

Soil erosion by water is a serious and continuing environmental problem. In the present study the Water Erosion Prediction Project (WEPP) model was used in the Dal catchment to simulate sediment yield. The study was conducted with the objective of calibrating and validating WEPP at the plot scale to examine its suitability for conservation planning. The WEPP model was calibrated using modified input parameters; further, the results were validated using a different data set. The soil erodibility (K-d) and critical shear stress (tau(c)) values vary from 1.70-2.7 and 0.27-0.76 Pa, respectively, for the study area. The average annual sediment yield (hillslope 1 and hillslope 2) was 6.759 t ha(-1) as against the measured value of 5.623 t ha(-1). The modeled values of sediment yield showed a close agreement with field observed values. The model also produced temporal variations of sediment yield on hillslope areas. The correlation coefficients were found to be 0.93 and 0.945, RMSE were 0.065 and 0.06 t ha(-1), and Nash-Sutcliffe efficiency indexes were 0.84 and 0.85 for the validation and calibration periods, respectively. The coefficient of determination (R-2) values were found to be 0.89 and 0.90 during calibration and validation of the model, respectively. Results indicated that the WEPP model simulated sediment yield from steep slope conditions and in forest conditions as well. The WEPP model was found to be an effective tool for simulating hydrological and soil erosion processes in watersheds having scarce data. (c) 2021 American Society of Civil Engineers.