Evaluation of WEPP Hillslope Model Efficiency in Predicting Runoff and sediment from rangeland experimental plots

Soil Erosion due to water is a major environmental problem in many parts of the world. Accurate estimation of water erosion is very important for the assessment of potential soil loss and storage capacity in reservoirs due to sediment deposition. The physically based Water Erosion Prediction Project (WEPP) model provides event-based runoff, erosion and sediment yield estimates. In this study surface runoff and soil loss simulated by the WEPP hillslope model were compared with measurements from two experimental plots containing rangeland vegetation. These plots were 12.5 m long and 2 m wide with slope gradient of 34%. Results showed, in general, WEPP hillslope model simulated fewer runoff events than measured data. The model tended to present better results when effective hydraulic conductivity was calibrated. Correspondence between measured and simulated runoff and sediment data were represented model efficiency coefficient 0.86 and 0.87, respectively.