Soil Erosion Simulation on Small Watersheds: A Modified ANSWERS Model

ABSTRACT A fundamentally-based, soil erosion and sediment transport model which is incorporated with a distributed-system hydrologic model (ANSWERS) was developed. It is a single-event model and considers typical upland erosion and sedimentation processes of splash erosion, flow erosion, sediment transport, and deposition. Channel erosion is also included. Erosion rates are related to hydrologic and hydraulic variables; soil characteristics; and surface and geographic condi-tions. The model was tested with data from two small agricultural watersheds of less than 10 ha in area. The model simulated sediment discharges which were com-parable to observed data.