Improving and calibrating channel erosion simulation in the Water Erosion Prediction Project (WEPP) model

The Water Erosion Prediction Project (WEPP) model has been widely used to assess the impacts of management practices and climate change on runoff soil loss at both hillslope watershed scales. However, representation channel erosion processes in WEPP not changed significantly since it was released. current (WEPP v2012.8) previous versions assume that input erodibility parameters are constant through time, which may lead erroneous detachment predictions, especially for cropland with substantial tillage operations. In this research, temporally values critical shear stress were replaced by daily updated values, using same temporal adjustments applied profile simulations rill detachment. Observed watershed-scale data from six agricultural watersheds calibrate compare performance simulating volumes losses before after modification. research showed v2012.8 modified (WEPP_CE) could satisfactorily simulate event-based hydrology outlets calibration. WEPP_CE varying demonstrated improved physical Continued improvement other process-based models is needed. can be evaluate effectiveness conservation further research.