Assessment of aquifer vulnerability using a geophysical approach in hyper-arid zones. A case study (In Salah region, Algeria)

Assessment of aquifer vulnerability to contamination is an effective tool for the delineation of groundwater protection zones. Geophysical approach was used to determine vulnerability zones in a study area located at 70 km north part of In Salah region, Southern limits of hydrogeological occidental basin in the outcrops Continental Intercalaire terrains. Ninety vertical electrical soundings (VES) were conducted in the study area. The results from the electrical survey data were used to assess the potential risk of groundwater pollution and define the protective properties of geologic layers as well as identifying suitable areas with poor, moderate, and high aquifer protective capacity rating. The inverted resistivity values and thickness of the layers above the groundwater table were used in order to estimate the integrated electrical conductivity (IEC) that can be also used for the quantification of aquifer vulnerability.