Hydro-geophysical assessment of aquifer zones in Niger semi-arid regions

Recognizing the critical role of groundwater as the primary drinking water source for millions worldwide, particularly in semi-arid regions like Niger, the UN Sustainable Development Goal (UN-SDG) aims to prioritize its sustainable management.Addressing water scarcity challenges through accessible, pure, and naturally filtered groundwater supports UN-SDG objectives for clean water and sanitation (Goal 6), ensuring its availability for domestic, agricultural, and industrial needs.This research contributes to the understanding groundwater potential zones and aquifer protective capacity in Niger's semi-arid region, supporting sustainable water resource management in Niger's semi-arid regions, Tillabery, Niamey, Dosso, Thoua, and Maradi.Using Vertical Electrical Sounding (VES) techniques, 166 data points were collected employing the Schlumberger electrode configuration.Geoelectric properties (resistivity and layer thickness) were derived, and Dar-Zarrouk parameters were calculated.Contoured maps visualizing longitudinal conductance (S), transverse resistance (T), and electrical anisotropy (), helped classify groundwater potential zones.The northeastern part showed low resistance, indicating a good groundwater potential zone.The aquifer is encountered at a depth of 11 m to 15 m in a sandy clay environment.Assessment of longitudinal conductance revealed a moderate to very good aquifer protective capacity, particularly in the southwestern and central-western sectors.To validate, eighteen borehole sites were analyzed, correlating findings with borehole drilling data to create a 3D aquifer thickness model.We found that the aquifer thickness is from 1.5 to 3.5 meters in certain regions exhibiting robust protective capacity, enhancing aquifer resilience against surface contamination.Analysis of the electrical anisotropy coefficient provided insights into geological structures like fractures and bedding planes, influencing fluid flow dynamics and contaminant movement.