Mapping and Assessment of Groundwater Recharge Zones in the Bongouanou Aquifer (Moronou Region)

Ensuring access to water and sanitation for all on the one hand, and ensuring sustainable and equitable management of water resources on the other hand, is one of the objectives for sustainable development. In the department of Bongouanou, most of the population's drinking water is supplied by groundwater contained in granite and schist basement aquifers This study delineates potential groundwater recharge zones in the Bongouanou department through an integrated geospatial and multi-criteria decision-making (MCDM) approach. The methodology combines remote sensing and GIS-based multi-criteria analysis with hydrochemical validation. Satellite imagery, base maps, and hydrochemical data were used to generate thematic layers representing the main factors controlling groundwater recharge, including slope, drainage density, lithology, fracture density, soil type, rainfall, and land use/land cover. These layers were weighted and overlaid to produce a groundwater recharge potential map. The results show that high recharge potential zones cover approximately 45% of the study area, while medium and low-to-moderate potential zones account for 33% and 21%, respectively. The reliability of the generated recharge potential map was validated using chloride concentration data. The development of a large-scale hydrogeological map of potential recharge zones for the fractured aquifers of Bongouanou, based on the integration of multiple datasets and methods, highlights the value of combining diverse sources of information.