An Integrated New GIS-Based Multicriteria Approach for Identifying Potential Sites for Groundwater Artificial Recharge

Abstract

Abstract Coastal zones are witnessing excessive abstraction of groundwater due to the exacerbated water demand, and this impacted groundwater depth in the major coastal aquifers. Groundwater Artificial Recharge (GWAR) is often presented as an adaptive solution to protect coastal aquifers. However, sites positioning for GWAR is still a matter of debate, notably in identifying factors controlling GWAR and thus erroneous site selection results. A new method for locating sites suitable for GWAR using remote sensing and GIS is proposed in this study. It consists in analysing several factors influencing the recharge rate and the relevant spatial aspects of runoff mechanism and integrates geographic patches (as polygons) with linear features of watercourses (as polylines) and eventually with the points which are represented by streams' confluences and represent the best sites for GWAR. The method was applied on the coastal zone of Lebanon as a typical Mediterranean Region, where water table has been lowered to more than 25 m and most coastal aquifers are exhausted; this has been associated with saltwater intrusion which is widely spread over several kilometres on-land. The systematic manipulation of the influencing factors in the studied zone enabled determining 13 sites with primary priority to GWAR, besides 15 sites with secondary priority. The results are helpful for decision makers and concerned stakeholder to select potential GWAR sites for better water management approaches in the coastal zones.