Hydrostructural mapping of basement aquifers in the Mô basin, NW Togo

• High fracture density boosts borehole yields (>5 m³/h) in rural Togo • Fracture density maps guide high-success drilling in basement aquifers • N-S/NW-SE hydrostructures control 80% of productive wells in Mô Basin • Remote sensing validates 1,989 lineaments (49.5 km) in Togo’s arid NW • Hydrostructural mapping sustains water access in West Africa’s drylands Access to clean water remains a major challenge in many African nations, including Togo, where rural communities in the Mô Basin face persistent water shortages. This issue has negative impacts on domestic water supply, sanitation, and agricultural productivity. This study focuses on the groundwater resources of the Mô Basin and aims to optimize access to clean water for rural populations by characterizing aquifer systems in crystalline basement formations. A multidisciplinary methodology was used, combining remote sensing for structural analysis of the Mô Basin, hydrogeological data (yield data from 291 boreholes), and geological and structural studies (lithology, fracture networks). Systematic data processing and modeling revealed that aquifer productivity is heavily influenced by hydrostructural attributes, particularly fracture density, spatial orientation, and geomorphological setting. The key findings indicate preferential groundwater accumulation along dominant structural trends: N-S, NNE-SSW, E-W/ENE-WSW, and NW-SE. Additionally, lineament analysis derived from satellite data enabled precise mapping of fracture corridors and preferential drainage zones, demonstrating a significant correlation with exploitable groundwater reserves. These findings are supported by strong linear correlations of 0.91 and 0.94 between fracture density and well yields, and between cumulative fracture lengths and the number of wells, respectively. This knowledge enhances the predictive accuracy of borehole siting in crystalline basement terrains, thereby supporting sustainable water resource management strategies. This research contributes to improving groundwater exploration frameworks in structurally complex environments, offering practical solutions for water-scarce regions in Sub-Saharan Africa.