A coupled GIS-MCDA approach to map the feasibility of Managed Aquifer Recharge

Managed aquifer recharge (MAR) is a water resource management technique that involves the intentional recharge and storage of water into groundwater systems. MAR is considered an innovative nature-based solution for increasing water availability, improving water quality, and reducing surface water runoff. However, the feasibility of implementing MAR projects depends on several factors, for example recharge water availability, water demand, and the intrinsic site characteristics (e.g., geology, hydrogeology) of the area.

The current study proposes an adapted approach of MAR feasibility mapping through the integration of GIS and multi-criteria decision analysis (GIS-MCDA). The geospatial feasibility of MAR application is evaluated by considering the suitability maps of four thematic layers, namely intrinsic, water availability, non-physical and water demand.  The applicability of this approach is demonstrated in Enfidha plain (NE Tunisia), for which multiple types of spatial and temporal datasets have been collected.   The selection of the criteria is done based on literature studies and MAR experts’ opinions with respect to their relevance to MAR implementation, whereas the weights are determined using analytical hierarchy process (AHP). Hence, an intrinsic suitability map was established via the integration of ArcGIS software and MCDA in a web-based platform, called INOWAS (https://inowas.com/). The results suggest that more than 80% of the total plain area is considered intrinsically suitable for MAR implementation.  The potential MAR feasibility of the demonstration site is expected to be established by overlaying the suitability maps of the three thematic layers.

In addition to standardizing the process of MAR feasibility, the derived maps constitute an asset in the process of planning and implementing effective MAR projects that help to ensure the long-term sustainability of water resources in the Sahel region of Tunisia.

Acknowledgement

This work is funded by National Funding Agencies from Germany (Bundesministerium für Bildung und Forschung – BMBF), Cyprus (Research & Innovation Foundation – RIF), Portugal (Fundação para a Ciência e a Tecnologia – FCT), Spain (Ministerio de Ciencia e Innovación – MCI) and Tunisia (Ministère de l’Enseignement Supérieur et de la Recherche Scientifique – MESRS) under the Partnership for Research and Innovation in the Mediterranean Area (PRIMA). The PRIMA programme is supported under Horizon 2020 by the European Union’s Framework for Research and Innovation.