Borehole Productivity Controlling Factors in Crystalline Bedrock Aquifer of Gkêkê Region, Center of Côte d’Ivoire

Abstract

The presence of both weathered rocks and fractured crystalline bedrock aquifers makes Hydrogeology in Gbêkê region of Côte d'Ivoire. Access to water in this region is not easy. This study focuses on the influence of borehole depth, weathering thickness and electrical resistivity of the geological structures on borehole productivity that exploit the crystalline aquifer system. Bivariate analysis was used to determine the relationships between these factors and specific capacity for measuring borehole productivity. The values ranged from 0.0088 to 2.20 m 3 •h −1 •m −1 . The analysis shows that there is no correlation between productivity and weathering thickness. However, weathering depths between 15 and 35 m provide the highest specific capacity values (Qs ≥ 1 m 3 •h −1 •m −1 ). For hydrogeological discontinuities interest, boreholes located in KH, QH and H anomaly curve types were the most productive. As productivity diminishes with depth, a deeper borehole can be more productive if it reaches a geological structure that is favorable for groundwater flow. Those hydrogeological parameters are extremely important in borehole productivity in Gbêkê region.

Assessing the hydrodynamic properties of the fissured layer of granitoid aquifers in the Tchologo Region (Northern Côte d'Ivoire)

“…In regions where geological formations are mainly composed of crystalline basement as is the case in Côte d'Ivoire (more than 97%), the identification of drainage and groundwater accumulation areas is fundamental for aquifer research. Works carried out in crystalline basement environments in Africa, Asia and Europe ( Holland and Witthüser, 2011 ; Jaunat et al., 2016 ; Roques et al., 2016 ; Douagui et al., 2018 ; Tagnon et al., 2020 ; Kouamé et al., 2019 ; Maurice et al., 2019 ; Hasan et al., 2020 ) show that these areas generally have fissured and fractured aquifers that provide sufficient water flows for population water supplies. However, these aquifers, due to the significant spatial variability of their hydrodynamic properties, are considered discontinuous and therefore complex.…”