Groundwater resources in arid regions play a crucial role in meeting water demands; however, they are facing rapid depletion due to unsustainable exploitation practices, exacerbated by climate change. As climate extremes intensify, there is a growing emphasis on harnessing flood and storm flows to replenish overdrawn aquifers. Floods can present a unique opportunity for restoring groundwater levels and mitigating saltwater intrusion into aquifers. The use of effectively managed floodwater for aquifer recharge offers a dual advantage by maximizing the potential of floods as a valuable water resource, while minimizing their negative impacts.

This work proposes an integrated approach to evaluate the geospatial suitability of groundwater recharge using floodwater across Qatar, a peninsula located in the eastern part of the Arabian Peninsula. We applied a Quantum GIS-based Multi-Criteria Decision Analysis (MCDA) approach, namely the Analytic Hierarchy Process (AHP), to delineate flood susceptible zones and groundwater recharge zones in Qatar, considering several influential topographical, hydrological, environmental, and anthropological criteria. The maps of flood susceptibility and potential groundwater recharge zones were validated using recent flooding events and existing recharge wells data, respectively. Sensitivity analysis was conducted on both variables to further assess their accuracy. The overlay analysis of the two validated maps, encompassing 98% of the entire country's surface, suggests that approximately 64% of the Qatar peninsula presents medium to excellent suitability for aquifer recharge using floodwater. The areas best suited for floodwater-based recharge intervention are located in the northern and coastal regions of the peninsula, while the urban areas and southwestern area are less suitable.

The findings of this study provide decision-makers with spatially explicit information for targeted aquifer recharge projects, potentially mitigating groundwater depletion, enhancing water security, and improving flood risk management in Qatar. In addition, we offer insights into further investigation areas, encompassing technical, economic, and regulatory considerations, to enhance the applicability and effectiveness of the proposed groundwater recharge strategies. The approach employed can be effectively applied in similar flood-prone arid regions and is adaptable to diverse contexts.