Spatiotemporal assessment of soil erosion risk using integrated RUSLE-GIS in Wadi Allith Basin, Saudi Arabia

Abstract Soil erosion represents a critical threat to natural resource sustainability in arid environments, yet validation of empirical models in hyper-arid watersheds remains limited. This study employs the Revised Universal Soil Loss Equation (RUSLE) integrated with Geographic Information Systems (GIS) and remote sensing to quantify rainfall erosivity and erosion risk dynamics in Wadi Allith basin, Saudi Arabia, across 2016–2018. RUSLE factors, rainfall erosivity (R), soil erodibility (K), slope length-steepness (LS), cover management (C), and support practices (P) were derived from WorldClim precipitation data, FAO-UN Soil Map, SRTM digital elevation model, and Landsat-derived NDVI. Results reveal a pronounced orographic gradient in rainfall erosivity, increasing 29 % from 2016 (120 mm yr −1 ) to 2018 (155 mm yr −1 ), with high-erosivity zones expanding from 15 % to 35 % of basin area. Despite this intensification, the basin maintains predominantly “slight” erosion risk (ERC 1–2, 10. This demonstrates that while low-gradient topography provides a geomorphic buffer, climate-driven erosivity increases threaten to breach critical erosion thresholds. The successful application of open-source GIS tools confirms cost-effective scalability for long-term monitoring in data-scarce arid regions. These findings inform targeted conservation strategies and highlight the urgency of climate-adaptive soil management in the Arabian Peninsula’s vulnerable dryland watersheds.