The Tunisian North-western region, especially Tabarka and Ain-Drahim villages, presents many landslides every year. Therefore, the landslide susceptibility mapping is essential to frame zones with high landslide susceptibility, to avoid loss of lives and properties. In this study, two bivariate statistical models: the evidential belief functions (EBF) and the weight of evidence (WoE), were used to produce landslide susceptibility maps for the study area. For this, a landslide inventory map was mapped using aerial photo, satellite image and extensive field survey. A total of 451 landslides were randomly separated into two datasets: 316 landslides (70%) for modelling and 135 landslides (30%) for validation. Then, 11 landslide conditioning factors: elevation, slope, aspect, lithology, rainfall, normalized difference vegetation index (NDVI), land cover/use, plan curvature, profile curvature, distance to faults and distance to drainage networks, were considered for modelling. The EBF and WoE models were well validated using the Area Under the Receiver Operating Characteristic (AUROC) curve with a success rate of 87.9% and 89.5%, respectively, and a predictive rate of 84.8% and 86.5%, respectively. The landslide susceptibility maps were very similar by the two models, but the WoE model is more efficient and it can be useful in future planning for the current study area.

In this study, physical and physicochemical experiments were carried out to improve the quality of feldspar ore in Sidi Aïch massive, located in the Gafsa region of south-western Tunisia. After determination of the mineralogical and the chemical composition, flotation methods were applied. In this study, non-hydrofluoric acid flotation methods used in feldspar-quartz separation were compared with each other and with the conventional HF/amine method. The results showed that conventional HF/amine method is the most effective and selective method.Experimental studies indicate that an acceptable concentrate for industrial application can be obtained from these rocks. The feldspar yield was used to evaluate the process efficiency. Besides, the cone shrinkage, water absorption, degree of vitrification, mechanical properties (flexural strength) and dielectric behaviour were used to monitor the quality of the recovered feldspars