GIS-based multi-criteria analysis and vulnerability method for the potential groundwater recharge delineation, case study of Manouba phreatic aquifer, NE Tunisia

Groundwater resources in semi-arid climate like Manouba region (North of Tunisia) have experienced deterioration of available water resources in terms of both quantity and quality. Managers and water engineers developed techniques to compensate for the high exploitation and remedy the poor quality of groundwater resources. One of the most important solutions is to focus on the recharge capacity of the aquifer. This paper aims to locate potential groundwater recharge areas using the multi-criteria approach. Delineation of groundwater potential recharge zones relies on physical parameters and groundwater vulnerability. Geographical information system can provide tools for handling multidisciplinary data used for each parameter. In this work, weighting coefficients attributed for parameters are assigned based on local conditions in the region, using the analytic hierarchy process by applying the intelligent decision system software. Results show that most of the study area has a groundwater recharge rate potentially moderate to high. Only 24% of the study area have low groundwater recharge rate located especially in Sebkhat Essijoumi and its vicinity, that mainly match to the least permeable and hilly areas. Considering both the vulnerability to pollution and the potential groundwater recharge capacity, the most suitable recharge sites are located in the North West of the study area.