Sediment transport in a small agricultural watershed - evaluation of WEPP simulations with measured data

During the 2002 growing season spatially and temporally distributed data on surface runoff, soil erosion, soil water content and crop development were collected from a 16-ha watershed in lower Austria, for which there was no information on water and sediment output. The watershed version of the Water Erosion Prediction Project (WEPP) model was applied without calibration to calculate the spatial distribution of erosion processes within the watershed. The field measured data were used to validate the simulation results. A good agreement between observed and simulated values was obtained for surface runoff, soil water storage and crop yields, whereas soil erosion was underestimated. Overall, WEPP is a useful and appropriate tool for estimating sediment transport in small agricultural used watersheds. However, calibration of the model input parameters is needed to improve sediment loss predictions.