Combined GPR, DC resistivity, and hydrogeochemical data for hydrogeological exploration: a case study at the Red Sea coast

Abstract

This study presents an approach of information on ground-penetrating radar (GPR), DC resistivity, and hydrogeochemical data for monitoring the potential of fresh groundwater zone, both quantitatively and qualitatively. This is applied in new urban area located at the coast of the Red Sea. First, a GPR survey is conducted to provide the preliminary data on the lithology, subsurface structure, and accumulation of groundwater in the aquifer. Then, a DC resistivity enabled the mapping of several geoelectric layers with info, water table, depth, and thickness of each water-bearing layer. Vertical electrical sounding is acquired and calibrated using available data of observation boreholes as well as the near GPR profiles to verify the results. In addition, water samples from drilled wells and springe are collected to evaluate hydrogeochemical characteristic and hydrogeological setting of the aquifers. Geophysical and hydrogeological datasets indicated the presence of two aquifers; the first aquifer occupies the zone of wadi deposits, and the second aquifer occurs in the fractured basement rock. The salinity in these aquifers shows heterogeneous distribution, but generally increases with depth, and is basically dependent to the prevailing structural framework and geological conditions. Such data integration shows the potential of the proposed approach in exploring and evaluating groundwater resources in semi-arid coastal plains using hydrogeological, DC resistivity, and GPR data.