Delineating groundwater recharge zones: semi-arid NW Algeria case study

International audience In arid and semi-arid regions, groundwater is a vital resource increasingly impacted by population growth and agricultural demands. This study identifies potential groundwater recharge zones in the Oued Isser-Sikkak Basin, northwestern Algeria, using the Analytic Hierarchy Process (AHP) integrated with Geographic Information Systems (GIS). Six thematic layers-land use, slope, geology, drainage density, lineament density, and rainfall-were weighted and combined to produce a recharge potential map. The basin was classified into five categories: very high (4%), high (33.7%), moderate (45.6%), low (12.5%), and very low (1.9%) recharge potential. The highest potential zones were found in the south and east, where limestone and dolomite formations prevail. Validation with field observations and previous research showed an 83.7% match, confirming the model's reliability. The study demonstrates the effectiveness of integrating AHP and GIS in assessing groundwater potential, offering a valuable tool for sustainable water resource management in data-limited, dryland areas.