Assessment of soil erosion in southern Tunisia using AHP-GIS modeling

Water erosion is a critical factor contributing to soil loss in southern Tunisia and poses a substantial risk to both ecosystems and water/soil conservation. This study employs an analytic hierarchy process (AHP) model integrated with geographic information systems (GIS) to evaluate the potential soil erosion risk and the relative significance of erosion factors within the Oum el Ghram and Bou Said watersheds. Ten factors, including rainfall, land cover/use, slope, elevation, runoff, drainage density, lineament density, lithology, soil type, and support practices, are analyzed. The results highlight land cover/use (27%), elevation (18%), and slope (14%) as the most influential factors. High to very high erosion classes predominantly occur in mountainous areas, covering 5.22% of the study area. Validation using the ROC curve demonstrates a satisfactory accuracy level for the AHP method (AUC = 0.85). To mitigate soil degradation and erosion risks, the findings advocate for implementing sustainable management strategies. Furthermore, this research offers insights for establishing effective soil management strategies under similar conditions in various studies. This work addresses the pressing issue of erosion in southern Tunisia, emphasizing practical solutions and valuable applications for soil conservation efforts.