Geospatial Assessment of Soil Erosion and Sedimentation Using RUSLE, AHP, and GIS

This study aims to assess and quantify soil erosion risk by integrating the Revised Universal Soil Loss Equation (RUSLE) with the Analytical Hierarchy Process (AHP) within a Geographic Information System (GIS) environment. The RUSLE model evaluates soil loss by combining five key factors: rainfall erosivity (R), soil erodibility (K), length of slope (LS), cover-management factor (C), and support practices factor (P). In parallel, the AHP framework incorporates nine geo-environmental parameters to refine the erosion hazard assessment through multi-criteria decision analysis. The integrated approach enables the generation of spatially explicit erosion risk maps, helping to identify vulnerable zones within the watershed. A primary focus of the study is the Dam, where sedimentation due to upstream erosion poses a critical threat. The outcomes of this research aim to inform soil conservation strategies and contribute to the sustainable management of a vital non-renewable resource, aligning with broader sustainable development goals (SDGs). The sediment delivery ratio (SDR) calculated shows that much soil will reach the basin and contribute to dam siltation. The final soil loss map established by the RUSLE model shows a maximum soil loss rate of 556.1 t ha⁻¹ year⁻¹ contributed over the entire watershed and an average of 49.77 t ha⁻¹ year⁻¹. The sediment delivery ratio is 0.53. A cross-section of different geo-environmental parameters shows that 37.51% of the watershed area is high to very highly vulnerable to erosion. The most dominant factors that take the maximum weight in the AHP matrix are the rainfall erosivity factor, the soil texture factor, the vegetation cover factor, and the slope.