Delineating groundwater potential recharge zones using remote sensing and GIS through the analytical hierarchy process (AHP) in northern Namibia’s landscapes

Water is a critical resource for human and ecological sustainability, particularly in semi-arid regions such as Namibia, where surface water is limited and evaporation rates are high. Consequently, communities rely heavily on groundwater, making sustainable groundwater management essential. Understanding groundwater recharge processes is therefore vital. This study delineates groundwater potential recharge zones (GWRZ) in three northern Namibian landscapes Uukolonkadhi, Okatjandja, and Okongo using remote sensing and GIS-based techniques. Satellite-derived thematic layers influencing groundwater recharge were analyzed in ArcGIS 3.2.2 and integrated using the Analytical Hierarchy Process (AHP). A cumulative score index (CSI), classified using mean and standard deviation, was applied to identify four recharge potential categories: very high, high, moderate, and low. Results show that more than 80% of the Okongo area falls within very high to high recharge zones, while Okatjandja and Uukolonkadhi are predominantly characterized by moderate to low recharge potential. Validation using the spatial distribution of pans, surface depressions, and seasonal ponds demonstrated strong agreement, with most features occurring in high to very high GWRZ. Additionally, the delineated recharge zones correspond well with aquifer potential classes from Namibia’s hydrogeological map. Areas with high lineament density, unconsolidated sediments, and low drainage density exhibit the highest recharge potential, providing a useful basis for groundwater management and land-use planning.