Groundwater exploration using geoelectrical resistivity technique at Al-Quwy’yia area Central Saudi Arabia

Abstract

Geoelectrical resistivity surveys were carried out in Al Quwy’yia area, located at the centeral part of Saudi Arabia, to map the acquifer and estimate the groundwater potentiality. The acquired vertical electrical sounding (VES) data sets have been collected along three longitudinal profiles trending East-West, perpendicular to the basement/sedimentary contact. The data sets have been analysed using 1D to obtain the initial figure out of the resistivity layers along the areas. Then, the data were inversion resistivity section using 2D inversion scheme. Information from two boreholes were incorporated during the processing to enhance the results and constrain the resistivity models with geological layers. The results revealed mainly two geoelectric layers which represent mainly the basement and sedimentary rocks. The basement rocks dip generally east ward, where the sedimentary section increases in this direction. The depth to the basement is about 50 m in the western part of the area and can not be reached from the acquired data in the eastern part. The contact boundaring between the basement complex and sedimentary rocks can be determined. The static water table is coincident with the limestone rock of Khuff formation as indicated from the comparison between the individual resistivity models and the two wells located at the study area. The thickness of the aquifer is increasing in the north eastern direction where the possibility of the groundwater potentiality is increasing. Key words: Vertical electrical sounding (VES), arid environment, Al Quwy’yia, 2D resistivity.