Estimation of Soil Erosion Rate in Gaushan Watershed Using RUSLE 3D Model

To reduce soil erosion, one of the most important issues is to quantify the amount of erosion and sediment so that planners can make correct decisions in line with the integrated management of watersheds. In this research, in order to evaluate the rate of erosion in the Gaushan watershed, we used the global equation of soil erosion in three dimensions and the geographic information system and remote sensing. The results of RUSLE 3D model were compared with the results of RUSLE model and real values. The rain erosivity factor was calculated using rainfall data and interpolation techniques. Soil erodibility was obtained using the soil map of the region. Land cover factor was calculated using NDVI index. The LS factor was also obtained using the DEM. The main difference between the RUSLE 3D model and the RUSLE model is the difference in how to calculate the LS factor in the RUSLE 3D model. The obtained results showed that the annual average erosion is 5.02 ton/ha/y. In the detailed studies of Gaushan watershed, the rate of erosion is 4.5 ton/ha/y. These results show that the RUSLE 3D model, in which the LS factor has been modified, has been able to estimate the basin erosion well.