Evaluation of shallow groundwater aquifer, west Gebel Libni, Sinai, using geophysical and remote sensing data

Groundwater resources represent the primary freshwater source in arid regions such as north-central Sinai. This study aims to evaluate groundwater occurrence using an integrated approach that combines GIS-based multi-criteria analysis, gravity data interpretation, and vertical electrical sounding (VES). Key controlling factors, including rainfall, soil, land use/land cover, drainage density, slope, and lineament density, were integrated to delineate groundwater surface recharge potential. The analysis classified the study area into five zones, with moderate to good potential areas showing spatial agreement with VESs locations. Gravity data filtering using various techniques revealed faults trending mainly N E -SW, WNW-ESE, ENE-WSW, E-W, N-S, and NNE-SSW, along with minor NW-SE and NNW-SSE trends. These faults may act as conduits or barriers to groundwater flow. Moreover, 2-D gravity data modeling estimated basement depths of 1.7 to 5.4 km, which reveals a thick sedimentary section that contains groundwater aquifers. Quantitative interpretation of 50 VESs identified a four-layer geoelectrical sequence, with the deepest layer composed of fractured limestone, representing the shallow aquifer in the study area at depths of 311–400 m with resistivity values ranging from 40.8 to 153 Ω.m. Lateral variations in the overlying marl and limestone layers were linked to shallow faults that match the major structural trends delineated using gravity data. Overall, this study demonstrates that integrating GIS-based multi-criteria analysis with the interpretation results of gravity and geoelectrical data provides a robust framework for identifying promising groundwater zones and delineating groundwater potential in arid and structurally complex regions with scarce well data, such as north-central Sinai.