GIS-Based Multi Factor Analysis for Positioning Water Harvesting Sites Integrated with Managed Aquifer Recharge

Abstract Runoff loss to the sea and seawater intrusion into coastal aquifers represent a dual hydrologic phenomenon in many coastal regions. In this respect, an integrated management approach must be adopted to mitigate the impact of this geo-environmental problem, through surface water harvesting and recharging (SWHR) it into the beneath rock formations. However, positioning suitable sites, for surface water harvesting where from this water can be artificially/spontaneously recharged, is often a challenge. This study handles this challenge with innovative multi factor analysis using GIS to identify the optimal sites for SWHR. For this purpose, thematic maps were analysed and systematically integrated with data retrieved from satellite images (e.g., Sentinel-2, SRTM, etc.). The obtained geospatial data represent main factors controlling surface water flow regime, infiltration potential and other relevant environmental factors. Being converted to GIS digital files with various levels of impact on SWHR, these factors were together systematically manipulated; and thus 28 sites were identified and hydrologically characterized. The produced SWHR sites' map serves decision makers to take proper actions for water management in coastal zones whether in the investment of surface water or the mitigation of seawater intrusion.