Groundwater resource evaluation using geoelectrical resistivity survey in the Ghard El-Hunishat area of New Delta project province, North Western Desert, Egypt

Abstract

The present study aims to assess the groundwater resources in the Ghard El-Hunishat area, North Western Desert, Egypt, as it is part of the national agricultural reclamation mega-project (New Delta). This involves defining the groundwater-bearing zones and estimating their thicknesses and depths, outlining their lateral extents, besides trying to estimate the aquifer groundwater quality. To achieve these objectives, geoelectrical resistivity measurements with a total of thirty-eight vertical electrical soundings (VES) distributed along seven profiles have been carried out using the Schlumberger configuration. VES data were acquired at a maximum electrode spacing (AB/2) of 1000 m. The interpreted data have been correlated and calibrated with the available borehole lithological information in the study area to minimize the uncertainty of the interpreted models. Data analysis and interpretation revealed that the subsurface stratigraphic sequence consists of five geo-electrical layers; the fourth one represents the saturated Moghra aquifer unit, where its resistivity ranges between 25 and 78 Ω m, and its thickness ranges from 116 to 172 m, while the depth to the top of this layer ranges from 99 to 168.5 m. The interpreted layer parameters were used to generate geo-electrical cross-sections, and then these sections were presented in the form of a 3D fence diagram showing the lateral and vertical extents of the subsurface geological succession in the study area. Contour maps were also created, showing the spatial distribution of the saturated aquifer parameters. The current research findings can contribute to a better understanding of subsurface geological situations and assess the suitability of the investigated area for anticipated agricultural and urban developments, as well as water management for related activities.