Comparison of the efficiency the RUSLE and EPM models in estimating soil erosion and sediment yield according to the sediment rating curve (case study: Jask-Gabrik watershed)

Soil erosion is one of the environmental, agriculture and natural resources problems. The aim of this research is applying the EPM and RUSLE models to the Jask - Gabrik Watershed, in order to estimate soil erosion and sediment. In this study, the factors affecting the water erodibility, consist of erosivity factor, soil erodibility, topography, vegetation cover, the sensitivity of soils and stones to erosion, land use type, steep slope percentage used in the models. Finally, the amount of erosion and sediment produced according to the RUSLE and EPM were compared with the observed sediment using Gabric sediment sampling gage station. The results showed that RUSLE model is estimated sediment, 30745 tons/ha/year while EPM model 10541.6 tons/ha/year. According to the results, the estimated erosion and sediment value of the RUSLE model is close to the sampling values (42414 tonnes/ha/year), then RUSLE model is more efficient. Finally, it is recommended, EPM model using for the initial phases, explanatory studies, overview, and identification while for more accurate and more detailed studies applied the RUSLE model.