Integrated geophysical and hydrogeochemical characterization of a fractured limestone aquifer in new Tuna El Gabel village, West El-Minia, Egypt

Abstract

Groundwater is a vital component of water supply in arid regions, such as West El-Minia Governorate, Egypt, where water scarcity is projected to worsen, with per capita water supply expected to drop below 500 m3 by 2025. In response, Egypt’s One and a Half Million Feddan (≈630,000 hectares) project aims to reclaim the Western Desert and develop new communities, aligning with the country’s Vision 2030 for sustainable development. This study conducts a comprehensive qualitative and quantitative assessment of groundwater resources in the region, evaluating their suitability for various applications. Using 16 vertical electrical soundings (VES), we constructed geoelectric cross sections and maps that reveal five distinct geoelectric layers. The main water-bearing formation, a fractured limestone layer with clay intrusions, varies in thickness, increasing toward the southeastern portion, where groundwater potential is higher, owing to the influence of local structural features such as faults and fissures. Hydrogeochemical analysis of 12 water samples indicates that, although groundwater is generally fresh (TDS < 1000 mg/L), all samples are classified as “very hard” (> 180 mg/L), making them unsuitable for domestic use without prior treatment. However, evaluation using the US Salinity Laboratory (USSL) diagram, Sodium Adsorption Ratio (SAR), Salinity Index (SI), Sodium Percentage (Na %), Residual Sodium Carbonate (RSC), Kelly’s Ratio (KR), Magnesium Ratio (MR), and Permeability Index (PI) demonstrates that the majority of samples are highly suitable for irrigation and livestock purposes. The practical results of this study identify the eastern sector as having higher groundwater potential and confirm that the aquifer is a viable resource for irrigation-based land reclamation, provided appropriate water management and treatment strategies are applied.