EVALUATING SPATIAL DISTRIBUTION OF SOIL EROSION USING WEPP EROSION MODEL AND GIS TOOLS: A REVIEW

Abstract

Soil water erosion is a major global environmental problem. In order to develop a comprehensive soil and water conservation plan, it is essential to estimate runoff and soil loss. Simulation models are important available tools for soil erosion assessment without costly and time consuming field tests. In this paper, the capability of the WEPP (Water Erosion Prediction Project) watershed model for simulating runoff and soil lossisreviewed. Monthly and event-by-event runoff and sediment yieldcan be simulated by the WEPP model.The geo-spatial interface of the WEPP model (GeoWEPP) is used in preparing the database with WEPP. The breakpoint climate data generator (BPCDG) and climate component of the WEPP model (CLIGEN) can be used to generate the climate file. The overall results of the model calibration may show over-predictions or under-predictions.The model may predict sediment yield for selected events with a low ENS but the model performance may be poor for continuous simulating and vice versa. The sensitivity analysis and calibration process can show that the sediment yield and runoff are sensitive in some parameters such as inter-rill erosion and effective hydraulic conductivity. The review indicates that the WEPP model can be used for developing soil and water conservation management plan.