The geoenvironmental factors influencing slope failures in the Majerda basin, Algerian-Tunisian border

In mountainous regions globally, landslides pose severe threats to both human lives and infrastructure, with the Mediterranean region, in particular, being highly susceptible to these destructive events that result in substantial damage to settlements and infrastructure. In this study, we employ a GIS-based approach to comprehensively characterize terrain instabilities along the Algerian-Tunisian border, recognizing the critical need for effective land planning and disaster mitigation strategies in this context. Our methodology integrates geological, geophysical, and geotechnical reconnaissance techniques and multi-criteria analysis, with a particular focus on geotechnical parameters. Our findings reveal significant slope instability within the study area; it is particularly concentrated in the mid-altitude slopes of the eastern basin, with high and very high susceptibility zones covering 20.89% of the study area. Validation of our model through ROC analysis demonstrates its high accuracy, with an area under the curve (AUC) value of 0.92. Crucially, slope gradients and precipitation emerge as key contributors to landslide occurrence, alongside Triassic lithofacies, which is a significant geological factor influencing susceptibility. These results emphasize the necessity of identifying high-landslide-susceptibility regions for sustainable land management and risk reduction, which will ultimately enhance the resilience of the studied region and mitigate the associated natural hazard risks.