Geophysical and geochemical studies to delineate seawater intrusion in Bagoush area, Northwestern coast, Egypt

Delineation of Seawater Intrusion Using Geo-Electrical Survey in a Coastal Aquifer of Kamala Beach, Phuket, Thailand

“…Furthermore, the fluid electrical conductivity and TDS of each artificial seawater intrusion was measured using a HANNA HI 9813-6 portable meter in order to determine the fluid resistivity ρ f luid . Based on several studies [4,5,[8][9][10][11], resistivity decreases when a formation is combined with seawater. Likewise, the correlation between the formation and fluid conductivities was evaluated.…”

“…Line-3 and Line-4-with 165 m long cables (3 m in spacing)-were set up to determine the interface between fresh and seawater in the study site. A Wenner array-which is usually applied for good vertical resolution (a dense near-surface cover of resistivity data) and clear images of groundwater, saltwater intrusion, and sand-clay boundaries-was an attractive configuration, because it provides a high signal to noise ratio [10,26]. The ERI data acquisitions are provided in detail in Table 1.…”

“…Furthermore, the electrical conductivity (the inverse of electrical resistivity) is controlled by the concentration of TDS [7], and resistivity is generally used as an indicator of seawater contamination as resistivity anomalies (i.e., low resistivities) generally indicate a seawater intrusion problem [8]. However, since groundwater chemistry analysis of hydrogeological and pollution research is expensive, labor-intensive, and time-consuming [9], electrical resistivity imaging (ERI), accompanied by limited groundwater chemistry data are increasingly being used as an effective tool because they are a non-destructive and efficient method for characterizing the subsurface, especially for quantitative and qualitative assessments of subsurface problems [10]. Sherif et al [7] applied geoelectrical and hydrogeochemical studies to delineate seawater intrusion in the outlet of Wadi Ham, UAE.…”

“…The researchers categorized the groundwater situation in their research area into three types based on the resistivity values: (1) seawater intrusion (1-10 Ohm-m), (2) dilution of saltwater (approximately Ohm-m), and (3) freshwater (50-100 Ohm-m). ERI and groundwater chemistry analyses were employed by Eissa et al [10] to investigate seawater intrusion in Bagoush area, Northwestern coast, Egypt. Their study confirmed that the brackish water zone varied from 7.0 Ohm-m to 15.0 Ohm-m while saline water plumes were determined with resistivity values from 3.0 Ohm-m to 7.0 Ohm-m.…”

“…In recent years, several studies have been conducted around the world to elucidate the spatial distribution of seawater intrusions, and to delineate the areas characterized by the presence of seawater, and how that influences groundwater resistivity values. Moreover, strategies have been implemented to control the salinization of groundwater [4,5,[8][9][10][11]. For example, Costall et al [12] researched and proposed a comprehensive study of ERI along coastal margins, which was validated with substantial evidence from seawater monitoring wells.…”