Modeling of Soil Erosion and Sediment Production with Three Models of WEPP, EPM and Fournier in GIS Case Study: Sulachai Watershed-Ardabil

Water and soil are the foundation of human life. Today, soil erosion is threatening these valuable resources and consequently human life. Therefore, it is necessary to analyze and control of soil erosion. For evaluating the quality and quantity of soil erosion many models have been proposed. In this study, we aim to analyze erosion and sediment production of the Sulachai watershed, using three models of WEPP, EPM and Fournier and GIS technique. In general, in WEPP model, the file related to each of the parameters was made and entered in the software Geo WEPP. In the EPM model, first the map of coefficients was prepared and then with respect to these coefficients, the map of erosion was prepared. Also, in the Fournier model, required parameters were calculated and placed in the relevant place. Finally, the amount of sediment was estimated with the mentioned three methods. The observed sediment content also was obtained by using gradient flow and sediment. WEPP model has three methods which are slope, catchment area and flow-direction. Estimated sediment by each of the above three methods, are 0.213, 0.178 and 0.785 respectively, and also with the EPM and Fournier models, about 0.241 ton/hectares/year. Also the observed sediment amount was estimated 0.241 ton/hectares/year. The results of this research showed that WEPP model has better performance than other two models in estimating erosion and sediment in the Sulachai watershed.