Enhancing groundwater recharge mapping in arid regions with geospatial multi-criteria analysis in the Eastern desert of Egypt

Groundwater recharge zones should be identified in order to address water scarcity while ensuring the sustainability of aquifers. The research utilized an integrated methodology that combined Analytic Hierarchy Process (AHP), Remote Sensing (RS), and Geographic Information System (GIS) techniques to identify groundwater recharge potential zones within the Qift-El Quseir area of Egypt's Eastern Desert. Eight key parameters, including drainage density, slope, topographic wetness index, lineament density, lithology, rainfall, land cover, and soil characteristics, were extracted from Sentinel-2 imagery, an ALOS PALSAR digital elevation model, long term gridded precipitation, and geological and land cover maps. AHP-based multi-criteria evaluation highlights lineament density and lithology as the dominant controls on recharge, followed by topographic and drainage characteristics. The resulting Groundwater Recharge Potential Index map classifies the basin into four categories, with 22.0% of the area characterized as excellent to very good, 34.9% as very good to good, 31.2% as good to moderate, and 11.9% as moderate to low. By combining these classes with class specific recharge ratios and mean annual rainfall (4.3 mm), the basin scale recharge is estimated at approximately 9.67 × 106 m3/year, equivalent to about 26.8% of annual precipitation, with nearly 80% of this recharge contributed by the two highest classes. Monte Carlo sensitivity analysis and Receiver Operating Characteristic evaluation, together with geophysical and hydrochemical data, confirm the robustness and hydrogeological plausibility of the mapped recharge zones. The findings show that multi-criteria spatial modeling accurately locates the optimal groundwater recharge sites, which would aid water resource planning and policymaking in arid regions.