Implementation of channel-routing routines in the Water Erosion Prediction Project (WEPP) model∗

The Water Erosion Prediction Project (WEPP) model is a process-based, continuous-simulation, watershed hydrology and erosion model. It is an important tool for water erosion simulation owing to its unique functionality in representing diverse landuse and management conditions. Its applicability is limited to relatively small watersheds since its current version does not simulate flow in permanent channels. In this study we developed a channel-routing module to simulate water flow in a permanent channel network. The module can utilize two methods: numerical kinematic-wave method and Muskingum-Cunge method. Results showed that, for appropriate temporal and spatial discretizations, both numerical solutions compared well with analytical solution of kinematic wave equations for simplified cases; otherwise, numerical dissipation from the kinematic wave solution, and numerical dispersion from the Muskingum-Cunge solution