Soil erosion assessment in the rainy mountainous areas of the eastern Mediterranean. A case study of the El-Sarout watershed

Abstract

This study provides a comprehensive assessment of soil erosion dynamics in the El-Sarout River Watershed, encompassing 598.15 km2 within the humid mountainous ecosystems of the eastern Mediterranean. Using the Coordination of Information on the Environment (CORINE) model, integrated with Geographic Information Systems and remote sensing, the research evaluates soil erosion susceptibility across varied landscapes. The CORINE model facilitates the creation of thematic maps essential for understanding soil erosion dynamics, including the Potential Soil Erosion Risk (PSER) and Actual Soil Erosion Risk (ASER) maps. PSER, derived from the Soil Erodibility Index, Erosivity Index, and Slope Index, identifies areas at risk under natural conditions. ASER refines this assessment by incorporating the Land Cover Index, which reflects current land use and management practices. Findings reveal that 18.56% (111.01 km2) of the watershed, particularly in the complex terrain of the southwest and north, faces high erosion risk. Another 11.7% (70.0 km2) exhibits moderate risk, while the majority, 69.74% (417.14 km2), experiences low risk. These results align with field observations of erosion features such as rills and gullies. The study emphasizes the complexity of soil erosion processes, highlighting the interaction between rainfall intensity, vegetation cover, and topography. Contrary to common assumptions, areas with dense vegetation may still be highly susceptible to erosion, particularly in steep regions subject to intense rainfall. The study calls the need for further research to establish negative thresholds for influencing factors and to incorporate rainfall intensity indicators into erosion models, aiming to enhance the precision and efficacy of soil conservation strategies.