Abstract
A hydrogeophysical investigation has been conducted along the NE part of the Gulf of Aqaba coast that covered a total area of about 40 km(2). The area represents a vital part of the ambitious national project NEOM that is a major outcome of the Saudi Arabia's strategic Vision 2030. The research aimed to provide decision makers with the characteristics of the main aquifer in the area in terms of its lateral and vertical extensions and quality of groundwater. To achieve the set objectives, an integrated methodology has been applied that is based on using electrical resistivity tomography (ERT) method and hydrochemical analysis of groundwater samples from the coastal aquifer collected via six shallow water wells. A total of 17 ERT profiles have been conducted; each has a maximum length of 350 m with a distance from the coast in the range 300-800 m. The derived two-dimensional and quasi-three-dimensional resistivity models successfully mapped the lateral and vertical extensions of the aquifer, determined the depth to the saturated zone, and provided the bulk resistivity of the aquifer. A basement uplift has been detected, indicating that the coastal aquifer is separated into northern and southern zones. The results related to the quality of groundwater were supported by the chemical analysis of the groundwater samples, which showed high concentrations of TDS and Cl-; this indicates a probable partial mixing of the groundwater with seawater. Water-quality index showed that the groundwater is unsuitable for drinking purposes, whereas it is classified as partially adequate for irrigation.