Integrated assessment of groundwater potential in Ngaoundal (Adamawa, Cameroon) using geoelectrical methods and satellite imagery

The Ngaoundal area faces a growing shortage of drinking water due to limited knowledge and management of existing aquifers. This study evaluates the hydrogeological potential of Ngaoundal using an integrated approach combining geoelectrical methods and remote sensing. A total of 51 vertical electrical soundings (VES) were conducted, identifying ten distinct curve types (Q, HK, KH, H, KQ, QH, HKH, K, KQH, and QHK) classified according to depth and resistivity. Apparent resistivity maps and VES analyses indicate lateritic soils at the surface, sandy-clayey soils at intermediate depths, and fractured or intact granitic bedrock at depth. Four 2D resistivity pseudo-sections reveal low (ρ < 350 Ω·m), medium (350 ≤ ρ ≤ 1,800 Ω·m), and high resistivity (ρ ≥ 1,800 Ω·m) zones, corresponding to weathered materials, fractured granites, and intact bedrock, respectively. Derived hydraulic parameters show hydraulic conductivity of 1.18–3.8 m/day, porosity of 21.34–29.18%, longitudinal conductance (S) of 0.029–0.030 Ω⁻¹, and transmissivity of 11.85–22.27 m²/day. Lineament mapping highlights a fracture network oriented mainly N045°E–N060°E and secondarily N020°E–N045°E, influencing aquifer distribution. Two aquifer types were identified: weathered (overlying) and fractured (bedrock) aquifers. Integration of geophysical, hydraulic, and structural data allowed the delineation of hydrogeological potential zones: the southern sector is highly favorable, the central sector moderately favorable, and the northern sector poorly favorable for groundwater exploitation. This integrated methodology provides a robust framework for sustainable water resource management and the strategic planning of water supply infrastructure in crystalline terrain regions.