Assessment of Soil Erosion Using the GIS-Based RUSLE Model: A Case Study of the Oued-Sly Catchment in the Middle Cheliff Watershed, Northern Algeria

Soil water erosion poses significant threats to soil fertility, agricultural productivity, and the integrity of water reservoirs. In this study, the risk of soil erosion in the Oued Sly catchment, located in the Middle Cheliff watershed of northern Algeria, is assessed using a Geographic Information System (GIS) integrated with the Revised Universal Soil Loss Equation (RUSLE) model. The catchment spans approximately 927 square kilometers and serves as a representative area for understanding erosion dynamics in the region. Several factors, including soil lithology, land use practices, human activity, topography, rainfall patterns, and vegetation cover, play a critical role in influencing soil erosion. To enhance the precision of the analysis, various datasets were employed, such as digital elevation models (DEM), soil and land cover maps, and data on rainfall and erosion control practices. These inputs were combined within a GIS framework to create thematic maps that visually represent the interaction of these factors in driving erosion. The results indicate that the majority of the Oued Sly catchment, approximately 90.7%, experiences low to moderate soil erosion, with average rates ranging from 23.4 to 40 tons per hectare per year. However, 9.3% of the catchment area faces severe erosion, with rates exceeding 40 tons per hectare annually. These high-risk zones, particularly concentrated in the central and down-stream regions, require immediate intervention. This research provides valuable insights for watershed management and highlights the utility of GIS-based mapping in prioritizing areas for erosion control measures. By identifying critical hotspots, the study emphasizes the necessity of proactive soil conservation practices to mitigate the adverse effects of erosion, ensuring sustainable agricultural productivity and protecting vital water resources. Effective mitigation strategies, particularly in the identified high-risk zones, are crucial for maintaining the long-term health and stability of the Oued Sly catchment.