Estimation of Annual Sediment and Soil Erosion in the Aras River Subbasin with the RUSLE Experimental Model and Landsat 8 Data

Soil erosion is a very serious problem and its assessment in planning and conservation operation in the watershed is very useful. To estimate soil erosion and to establish soil erosion management plans, many computer models have been developed and used. The information needed to control soil erosion is possible by applying the revised universal soil loss equation. The aim of this study, prediction of annual soil loss and sediment load using RUSLE in geographic information system and remote sensing environment. RUSLE factors map including rainfall erosivity (R), soli erodibility (K), slope length (L), slope steepness (S), cover management (C) and support practice factor (P) were prepared using geographic information system and remote sensing. Finally, the erosion risk map was prepared using the integration of the geographic information system and weights obtained from the Analytical Hierarchy Process (AHP) process. The results showed that the mean values of R, K, LS, C and P indices were 207.443 (MJ / mmha-1hr-1 / year-1), 0.63 (t / ha, MJ.mm), 382.997, 0.364, 0.8 (t/year) in the studied basin and the most important factors in the amount of soil erosion were topography and precipitation factors. Also, the results showed that the annual erosion and sediment load in the study area was 7461.69 tons per year and the annual erosion had the highest weight (0.308) and the soil erodibility factor had the lowest weight (0.04). The final erosion risk map also showed that the large area of the studied area is eroded in a high-risk class (285.5 km2) and very high (47.9 km2), indicating that a serious management decision to be taken in the region. According to the results of this research, it is necessary to carry out appropriate protection in the area and these sites can be selected from the output of the RUSLE model.