Hydrogeophysical characterization of the Southern Red Sea coastal aquifer, Saudi Arabia, using Time-Domain electromagnetic method

Abstract The research aims to characterize the shallow coastal aquifer of the Red Sea in terms of lateral and vertical extensions and to determine the factors controlling the quality of groundwater using the Time-Domain Electromagnetic sounding method. The aquifer consists of alluvial sediments with an increasing thickness toward NE. Groundwater resistivity is variable from less than 5 Ω.m at the coastal strip to 20 Ω.m at 5 km toward NE. Furthermore, resistivity reached up to 100 Ω.m in other parts of the area. Variations in aquifer resistivity are attributed to lithological changes and seawater intrusion. Aquifer resistivity and the total dissolved solid values from wells indicate that the aquifer is adequate for agricultural usage except along the coastal areas.