A refined geospatial approach for groundwater potentiality mapping and optimal retention dams site selection: a case study Wadi Sudr, Gulf of Suez, Egypt

Abstract In response to the increasing global demand for potable water, assessing groundwater potential in aquifers has become essential. It is also crucial across various sectors, including human consumption, agriculture, and industry. Geographical information system (GIS)-based studies have gained attention due to their efficiency and capability to provide immediate insights into groundwater resources for further development. In the Wadi Sudr basin, Egypt, this study combines Geographic Information System (GIS) with Analytical Hierarchical Process (AHP) techniques to define groundwater potential zones. Ten thematic layers, encompassing factors e.g. lithology, topographic wetness index, land slope, drainage density, lineament density, land surface temperature, slope curvature, topographic ruggedness index, flow velocity, and land elevation, were prepared and analyzed for demarcating groundwater potential zones. The AHP method gives weights to each class based on their features and water potential capacity. Cross-validation with existing groundwater information yielded an overall accuracy reaching 99%. The groundwater potential zone map was categorized into five distinct classifications: very high, high, moderate, low, and very low. Around 35% of the research basin had a moderate groundwater potential zone, whereas high, and very high zones accounted for 20% and 5% respectively. Zones with very high groundwater potential were overlaid with areas of very low stream power and very low sediment transport index. The intersections were compared with stream locations, proximity to roads, faults, and groundwater wells using Boolean logic analysis, identifying 12 optimal dam construction sites. This approach offers refined and valuable insights into groundwater resources and supports sustainable water management in arid regions.