Hydrogeological characterization and aquifer recharge mapping for groundwater resources management using multicriteria analysis and numerical modeling: A case study from Tunisia

Abstract

In hydrogeological modeling, the groundwater flow and the reservoir structure are key factors. The evaluation of the aquifer system functioning and the water availability are the main issues in water resource management. In this study, a groundwater flow model and Geographic Information System tools were used to manage water resources in arid area. In this study, multicriteria approach using a weighted-rating process was adopted to establish a map showing areas suitable for groundwater recharge. The high rechargeability index covers 45% of the total shallow aquifer extension and the medium index covers only 29%. Recharge rates are introduced to the established model using the software MODFLOW. The impact of the groundwater recharge is then evaluated by hydraulic heads simulation and water budget analysis. The model exploitation illustrates the impact of the water recharge on the hydraulic heads. In the first scenario, the increase of the exploitation of 20% decreases the hydraulic heads. In the second scenario, with a constant exploitation and precipitation, the impact of a recharge dam increases the piezometric levels. Results are helpful to manage water resources and to help decision makers and planner.