Application of EPM model in soil erosion evaluation (Case study, Shazand watershed-Saveh Dam)

In this paper, the Shazand catchment area have been simulated  using the geographical information system  (GIS) with an accuracy of 10 × 10 meters and various parameters required in the form of digital layers in the ArcGIS environment. Then, using the EPM model, the erosion zoning map of this basin located around the Saveh dam was prepared and its annual precipitation rate was estimated. In the following, the output of the model was compared with the hydrometric method. According to the results of EPM model, sediment yield from stations of Poledoab, Bazaneh, Toureh and Shazand using EPM model are 288103.81, 18963.83, 43079.2 and 20583.76 respectively, whereas hydrometric method shows values 335285.42, 23937.42, 36459.09 and 42781.69 ton per year, respectively. Also comparison of EPM model with hydrometric method shows a good correlation. Results show accuracy of 86%, 82%, 48% and 79% for Poledoab, Toureh, Shazand and Bazaneh stations, respectively. Assessments show that EPM model with acceptable accuracy provides good results in order to predict the mximum annual sediment yield.