Assessing the sensitivity of land cover (C factor) to water erosion in the Ksob watershed, central Algeria

Abstract

Water erosion is a critical environmental and economic issue, causing soil fertility loss and land degradation, recognized globally as one of the most severe natural threats. Algeria’s high topography, diverse vegetation, and heavy rainfall make it particularly vulnerable to water erosion. This study employs the Revised Universal Soil Loss Equation (RUSLE) model integrated with geographic information systems (GIS) to analyze the Ksob watershed from 2017 to 2023. It examines seasonal and interannual variations in the vegetation cover management (C factor), assesses the impact of changes in land use and land cover (LULC) on soil erosion, and investigates the relationship between the C factor and soil erosion. Findings indicate significant soil loss variations due to changes in vegetation cover: reduced vegetation increases erosion rates, while dense vegetation mitigates them. Despite cultivated land expanding from 25.39% to 35.84% during the study period, the average annual soil loss rose by 11.21%, from 9.06 t ha-1 yr-1 to 10.08 t ha-1 yr-1. Spatial analysis revealed that low erosion classes covered approximately 70% of the area, with summer and autumn identified as the most erosive seasons, showing rates over 10 t ha-1 yr-1. The study confirms a strong relationship between vegetation cover and erosion rate.