Integrated Approach for the Characterization and Modeling of a Fractured Basement Aquifer: Application to the Pézouan Industrial Site, West-Central Côte d’Ivoire

Abstract

Groundwater resources play a strategic role in supporting industrial development in crystalline basement regions where surface water availability is often limited or highly variable. This study aimed to identify hydraulically productive structures and develop a conceptual hydrogeological model of the aquifer system supplying the SIPIC industrial site near Issia, western Côte d’Ivoire. An integrated methodology combining morphostructural analysis, electrical resistivity investigations, vertical electrical soundings (VES), borehole data analysis, and three-dimensional hydrogeological modeling was implemented to characterize groundwater occurrence and flow within the fractured crystalline basement. Structural mapping revealed a predominance of fracture orientations around N120°, while geoelectrical investigations highlighted several conductive zones interpreted as potential groundwater-bearing structures. The VES results identified favorable aquifer horizons mainly located between 50 and 110 m depth. Borehole validation confirmed the reliability of the proposed targeting criteria. The highest yields were recorded in boreholes drilled at the intersection of hydrogeological discontinuities and structural lineaments, associated with W-shaped geoelectrical anomalies and H-type sounding responses. Boreholes F2 and F3 yielded 35 m 3 /h and 40 m 3 /h, respectively, demonstrating the strong influence of structural controls on groundwater productivity. The three-dimensional hydrogeological model revealed a multilayer aquifer system composed of an unconfined aquifer between 35 and 50 m depth and two deeper semi-confined to confined aquifers located between 55 and 70 m and between 80 and 105 m depth. Groundwater storage and flow are primarily controlled by the interaction between the weathered layer and hydraulically connected deep fracture networks. The results demonstrate that integrating structural, geophysical, and hydrogeological datasets significantly improves the identification of high-yield groundwater targets in fractured basement environments. The proposed conceptual model provides valuable support for future groundwater development and sustainable water resource management in crystalline basement regions of West Africa.