Application of geophysical techniques for shallow groundwater investigation using 1D-lateral constrained and 2D inversions in Ras Gara area, southwestern Sinai, Egypt

Abstract There is an urgent need for greater water resources to support sustainable development in Ras Gara area of southwestern Sinai. Determining the water-bearing zones shallow Quaternary aquifer Araba Formation study region therefore main objective research. This will be done by using a variety geophysical techniques, such as DC resistivity sounding and seismic refraction surveys. Using Schlumberger array (max. AB = 1200 m), data were gathered at 27 VES locations along five primary profiles. At same locations, spreads totaling 115 m length also performed. One-dimensional laterally constrained (1D-LCI) inversion only applied order generate best-fit model, whereas 2D other datasets. The divided up into geo-electrical layers based on results 1D-LCI data, classified fresh (third layer) saline bearing-zones (fourth layer). values fresh-zone range from 8.7 26.7 ?.m, with low (5–7.5 ?.m) found some sites, while saline-zone between 0.9 3 except (14.4 VES-04. depths (2.4–15.6 m) (8.7–28.5 zones, respectively. In this region, resistive (about 10–100 ?.m) intermediate high conductive (< 10 2D-DC inverted model represent aquifer, basement rocks represented deep, extremely layer that can reach 40,000 ?.m. Three subsurface are identified ( V P1 400–1100 m.s ?1 , P2 1200–1900 P3 2400–5400 ). saturated zone second (depth, 3.7–20.5 m). reflected last velocity. previously available hydro-geological map show good degree concordance. eastern portion area, additional wells could drilled resources.