Application of the multi potential geophysical techniques for groundwater evaluation in a part of Central Sinai Peninsula_ Egypt

Abstract

This study highlights the groundwater evaluation of the Nubian sandstone aquifers regarding assessing the main structural elements, trends, and depth to the basement rocks that control the groundwater aquifers in Egypt's central Sinai area. Gravity and magnetic data were analyzed using different techniques, such as wavenumber filtering, least-squares separation techniques, and tilt derivatives. Euler deconvolution with different structural indexes (SI), power spectrum analyses, 3-D crustal modeling. The deep-seated structures affecting the study area, and the basement depth, which range between 1170 and 4590 m., have been utilized. The main structural trends affecting the study area were delineated to control the groundwater aquifer's regional geometry. Moreover, it was found that the NorthWest-SouthEast trend direction – Suez Gulf trend – was caused by primary shear, and the NorthEast-SouthWest trend direction – Aqaba Gulf trend – was caused by the secondary shear. The direction of each trend's lateral movement was to the right and the left, respectively. Meanwhile, the geoelectrical resistivity measurements were also utilized to determine the ground water-bearing formations using eighteen deep vertical electrical soundings (VES) stations. The results revealed the depth to the uppermost part of the Nubian sandstone aquifer ranging between 598 and 1106 m; the combination of the depth to the uppermost part of the Nubian aquifer, the depth of the basement relief map revealed that the aquifer thickness varies from 430 to 3750 m, and the resistivity values ranging between 22 and 214 Ω.m.