Joint Electromagnetic-Terrain Conductivity and DC-Resistivity Survey for Bedrock and Groundwater Characterization at the New Al-Obour City, Egypt

Abstract

A multi-spacing electromagnetic–terrain conductivity survey profile and vertical electrical resistivity soundings were carried out at New Al-Obour City, Northeastern Cairo. The chief purpose of this survey was to characterize the bedrock, and groundwater occurrence, and hence to image both the surface and subsurface structures. The water is used mainly to meet the demands of the agricultural sector in the area. Accordingly, a set of sixteen Multi Spacing Electromagnetic Terrian Conductivity profiles and 11 vertical electrical soundings were done from September 2018 to March 2019. The data sets were transformed–inverted comprehensively with regard to stitched one-dimensional (1D) electrical resistivity smoothed-earth models. These sets were used efficiently in the interpretation of the geologic sequence of bedrock through successive conductive anomalies and electrically resistive. Remarkably, the obtained subsurface electrical resistivity structures are coincident with the mapped field geologic faults. The current study proved that a comprehensive Multi Spacing Electromagnetic Terrian Conductivity and vertical electrical sounding resistivity survey could help optimize geotechnical exploratory work. The results of the interpretation of geoelectrical data indicate that the elevation of the top of the groundwater aquifer ranges from 60-70 m above sea level.