Evidence of geoelectrical resistivity values on groundwater conditions in Wadi El Natrun and its vicinities, West Delta, Egypt (cases studies)

Abstract

Recently, Wadi El Natrun and its surroundings have witnessed intensive investments in land reclamation, including the arbitrary drilling of hundreds of groundwater wells. Currently, serious hydrogeological and environmental problems have been addressed, such as groundwater quality degradation and water head drop. Electrical resistivity measurements were performed at six locations across the study area to assess its ability to reveal the heterogeneous subsurface stratigraphic and hydrogeological setting of groundwater aquifer(s). The geoelectrical results successfully reflect the current vulnerable hydrogeological setting of the study sites. The current study highlights the current practice in which farmers rely on isolated 1-dimensional vertical electrical sounding (1D VES), which is not the only exploration tool for such electrically conductive stratigraphic succession. One of the main findings is addressing the advantage of applying 2-dimensional electrical resistivity imaging (2D ERI), where it offers a more robust view of both vertical and lateral variation of the investigated subsurface section (Case 3). On the other hand, the Geographic Information System (GIS) could mirror the present groundwater potentiality status, where both GIS analysis and resistivity results coincide, and where the good potentiality zone is restricted to the west and southwest directions of the study area (area of interest (aoi)), where the resistivity values of water bearing are relatively high and lie on the main drainage (Cases 2, 5, and 6). On the contrary, poor potentiality zones are deemed because of their proximity to tiny attributers, and are characterized by low resistivity values (Cases 1, 3 & 4), Finally, the current research study demonstrates the significance of combining morphometrical analysis with geophysics techniques for such environmental problems, where groundwater is primarily controlled by geomorphological features and geological conditions, including lithology and geological structures.