Suitability map for solar photovoltaic desalination farms using GIS and multi-criteria decision analysis

The Grombalia Basin, located in Northern Tunisia, is facing significant challenges related to water scarcity. The cultivation of citrus fruits in this region, supported by the government, has become increasingly vulnerable to the impacts of climate change, including reduced rainfall and more frequent drought periods. The agricultural sector faces a crisis due not only to the lack of water resources but also to inadequate management (water losses in irrigation systems). This study aims to delineate the most suitable areas for implementing solar photovoltaic (PV) desalination farms utilizing abandoned brackish groundwater. A Fuzzy Analytical Hierarchy Process (FAHP), integrated with Geographic Information Systems (GIS), is employed as a Multi-Criteria Decision Analysis (MCDA) approach. This paper evaluates potential sites based on climatic, socioeconomic, and environmental factors. The FAHP framework determines criteria weights through pairwise comparisons, ensuring robust and systematic decision-making. The results indicate that the most suitable sites are located north of the Grombalia basin, which currently lacks access to external water resources for irrigation. The "Dependence of Farmers on Water Resources (DFWR)" is the most sensitive criterion, and the most suitable sites remain relatively the same despite variations in weighting. These findings will assist farmers in using solar energy to desalinate brackish groundwater, thus ensuring the sustainability of their crops and preserving their citrus heritage.