Groundwater recharge zone mapping using GIS-based multi-criteria analysis: A case study in central Tunisia (Maknassy Basin)

The groundwater recharge zone mapping often requires a large amount of spatial information and criteria. Geographic information systems are capable of managing large amount of spatially related information, providing the ability to integrate multiple layers of information for multi-criteria analysis. To show the capabilities of GIS techniques for mapping groundwater refill zone in arid area, a study was carried out in the Maknassy basin located in Central Tunisia. This evaluation incorporates historic rainfall data analysis, watershed drainage density, surficial geology and aquifer boundary conditions. The study basin is categorized according to the previous criteria. Multi-criteria analysis is performed to evaluate suitability to the groundwater recharge for each factor, according to its associated weight. The thematic layers were integrated with one another using the weighted aggregation method to derive the groundwater recharge map. The results demonstrated that the GIS methodology has good functionality for mapping groundwater recharge zone.