Estimating the sedimentation of Aladyzgeh catchment area by using WEPP model in GIS environment

Soil is considered as one of the most important elements of the environment. Soil erosion is an unavoidable phenomenon that increasingly destroys soil and pollutes water. Accurate estimation of water erosion and deposition of sediments is very important to evaluate potential soil loss and storage capacity of dams. Water Erosion Prediction Project (WEPP) is a computer model that can estimate erosion and sediment of Hill slope and catchment area , based on each individual precipitation event or in successive years. The data required for WEPP model are entered in four files, namely soil file, management file, climate file and slope file. In this study, water erosion and sediment amount was estimated by three methods of Hill slope, catchment area and flow path. In these methods sediments estimation were 0.623, 0.325 and 0.824 ton/ha/year, respectively. The results were compared with the observed value (0.665 ton/ ha/ year) of Aladyzgeh. on this basis, the Hill slope method was closer to the observed value (0.665 ton/ ha/ year) of hydrometric station and is suitable for estimating the erosion and sediment amount in Aladyzgeh catchment area.