Quantitative Assessment Of Soil Loss Prediction Using The Revised Universal Soil Loss Equation (RUSLE) In A GIS Framework In Wadi Dhahban, Asir Region, Saudi Arabia

Abstract

This paper aims to estimate the amount of soil loss by water erosion basin for Wadi Dhahban, through the application of the global equation for soil loss (R * K * LS * C * P). Rainfall (R) was calculated by collecting monthly rainfall data for the period between1980-2020, Monthly Precipitation Datasets, World Clim. 2.1 (January 2020). The map of the aggressive rain factor, in addition to the map of soil erosion factor (K), has been prepared, through the results of the analysis of soil texture. Then, the map factor (LS) which is the gradient grade slope length is obtained through the ArcGIS program. Besides, a land use map of the (dimensionless) C-factor land management factor, which took into account the role of different types of vegetation cover and different methods of land use, has been prepared. The (dimensionless) conservation practice factor (P-factor) relies on soil conservation techniques and the data set to (Landsat 8, (ASTER) Global Digital Elevation Model Version 3 (GDEM 003), and the global land use/land cover (LULC) map). This shows that an extended part of the area is undergoing a severe loss. The mean annual soil loss is predicted as about 36.99 (t/ha-1 year-1) for some watersheds that show extended soil loss. The degrees of soil loss are classified into slight, moderate, high, very high, severe and very severe). Soil loss decreases not only agricultural productivity, but also reduces the water availability. In the current study, an effort to predict potential annual soil loss has been made. For the prediction, the Revised Universal Soil Loss Equation has been adopted in a GIS framework. The RUSLE factors were calculated (in the form of raster layers) for Wadi Dhahban to create soil erosion maps, which can serve as effective inputs in deriving strategies for land planning/management in the environmentally sensitive mountainous areas.