Geophysical and hydrogeological investigation to study groundwater occurrences in the Taref Formation, south Mut area - Dakhla Oasis - Egypt

- Depth to the upper surface of the Taref sandstone aquifer ranges from 34.9 m to 68.0 m.
- Dar Zarrouk parameters were used to differentiate the areas of confined conditions from that of unconfined conditions.
- The aquifer rock type is arenite sandstone and its main component is quartz grains.
- Porosity values of this aquifer ranges from good to very good and the aquifer has high potentiality.
- Groundwater salinity of this aquifer is suitable for all purposes.

Integrated geophysical and hydrogeological techniques can give vital information about groundwater occurrence in the south Mut area, where groundwater is the sole source of water supply in this arid area. Quantitative interpretation of the Vertical Electric Soundings (VES) clarified the geoelectric succession in the study area. Geoelectric parameters (resistivity and thickness) of each geoelectric layer and the available data of the existing wells were used to illustrate the vertical and spatial extensions of the encountered layers, depth to the water-bearing layer, the structures affecting these layers, water level and groundwater flow of the concerned aquifer.Groundwater in the study area occurs under confined and semi-confined conditions in the northern part and it occurs under unconfined conditions in the southern part. Dar Zarrouk (DZ) parameters were calculated to differentiate the areas of confined conditions from those of unconfined conditions. Groundwater salinity ranges between 343 and 654 ppm which is suitable for all purposes and its type is calcium sulfate and sodium sulfate.Petrophysical analyses were carried out on the collected rock samples to evaluate their mineralogical and pore properties, which showed that this aquifer is composed of arenite sandstone with good porosity.The results of the analysis of three constant pumping tests revealed that the hydraulic conductivity and transmissivity have high values, indicating that the aquifer has high potentiality. Combining the geoelectrical and hydrogeological results, the best sites for drilling new productive wells were recommended.