Geoelectrical resistivity and geochemical method for groundwater investigation in the coastal sediment

Abstract

This research presents new investigations on the identification and mapping of heavy metals in aquifer systems using geoelectrical methods, water samples, and geochemical analyses. The subsurface was investigated using a total of three geoelectrical survey lines in the Wenner Schlumberger configuration. Six samples—three from bore wells, two from rivers, and one from the sea—were collected for additional laboratory examination in order to observe the quality of the water samples and variations in hadrochemical water samples in the research area. Soil samples collected from three different places were geochemically analysed. Cd concentration (0.94-2.42 mg/kg) was found to be higher in the northern portion of the study site, and Cr concentration (4.39-72.98 mg/kg), Ni concentration (12.11-47.69 mg/kg), and Co concentration (7,19-12,86) were found to be higher in the southern section. While Cd, Cr, Ni, and Co distribution of heavy metals are quite high in the northern and southern areas of Galesong beach, they are relatively low in the middle. A geochemical study of soil samples reveals that Cd and Cr concentrations are significantly high in the resistivity zone (<20 Ωm). The environmental resistivity value is low from the center zone to the northwest. The heavy metal zone in the aquifer system can be simply represented by the geoelectrical resistivity distribution presented in the form of a depth section, even though the resistivity value of more than 40 Ωm can be regarded as an aquifer zone.