Integrated approach for landslide characterization in Northern Tunisia using electric resistivity tomography, geotechnical analysis and GIS tools

Abstract

In Northern Tunisia, where complicated geological and hydrological conditions increase slope instability, landslides constitute a significant geohazard. The purpose of this study is to use an integrated approach that combines GIS-based analysis, geotechnical investigations and Electrical Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES) to characterize landslide-prone areas. ERT and VES reveal low-resistivity zones that correspond to clay, water-saturated layers that strongly correlate with unstable slopes. Geotechnical tests confirmed this susceptibility, indicating reduced compressibility. Field observations, geophysical and geotechnical data, integrated with topographic information in GIS, revealed slope deformation and areas of moderate to high instability. The results show that the landslide evolved into a complex form, with a failure surface reaching approximately 25 m. This study confirms that combining geophysical, geotechnical and GIS techniques is effective for monitoring landslide processes. This integrated methodology improves hazard assessment and guides risk mitigation and land-use planning.