Satellite remote sensing and GIS-based multi-criteria analysis for assessing the groundwater recharge potential zones in the Regueb basin (central Tunisia)

The groundwater constitutes the major water resource in the Regueb region, which is one of the most important agricultural areas in Central Tunisia. Regueb has an arid climate with minimal amounts of precipitation that result in insignificant natural recharge of its aquifer compared to the overexploitation of groundwater for agricultural activities. This study aims to map groundwater recharge areas across the Regueb basin using remote sensing and geographic information system (GIS) techniques. The map indicates the potential recharge areas in the basin of interest. The areas are classified as poor, low, moderate, good, or excellent depending on the potential recharge level. Mapping the potential groundwater rechargeareas can assist in effectively and sustainably managing water resources. In this study, two potential recharge maps are established based on the weights of the basin characteristics; soil texture, land use/cover, lineaments, slope, and drainage density. For developing the first map, the weights of these factors are obtained from the literature. However, for the second map, the weights are estimated using the analytic hierarchy process (AHP). For each of the poor, low moderate, and good recharge zones, the percent area is similar in the two generated maps. The excellent recharge zones represent 22.02% of the basin’s total areas, in the map developed using factors weights from literature. However, in the second map where weights are estimated using AHP, the excellent recharge zones represent 29.2% of the basin’s total area. Overall, the most effective groundwater potential recharge zones are located where the lineament density is high, the drainage density is high, and the slope is low.