Estimation of Soil Erosion and Sediment Yield Based on Satellite Imagery Using the GIS Technique and Employing Erosion Potential Method (EPM) on Watersheds (Case study: the Dez Watershed)

Worldwide, soil erosion by water is one of the most important factors in land degradation, and is a critical environmental hazard of modern times. The present study aims to estimate the average annual specific production of sediments and the intensity erosion map at two sub-basins of the DEZ Watershed, south-west of the Lorestan Provine, Iran, namely Absorkh and Keshvar using the Erosion Potential Method (EPM),the Geographical Information System (GIS) and the Remote Sensing (RS) techniques. The total area of these sub-basins is 19920 hectares. Nearly 60 percent of the area has negligible vegetation cover or bare land. The study area can be categorized into slight, moderate, high and very high erosion zones. The amount of soil erosion and sediment yield predicted by the EPM model were 3203.718 and 2204.844 m3.km-2.y-1, respectively. The areas located at the middle and southern parts of the watershed were subjected to significant erosion due to the geology formation and vegetation cover and probably competent geological formations, while the area at the northern part was relatively less eroded because of verdant land cover. The measured sediment yield of the watershed at the Keshvar Hydrometric Station was approximately 2223.178 m3.km-2.y-1, which confirmed the satisfactory performance of the EPM Model.