Study of the productivity and hydrodynamic properties of fissured aquifers in the Gagnoa region

Located in the central-western part of Côte d'Ivoire, the subsoil of the Gagnoa region consists of volcanic sedimentary formations and granitoids with extensive fracturing. This complex Precambrian bedrock contains most of the region's water resources. The aim of this study is to gain a better understanding of how this type of aquifer works by determining the hydrodynamic parameters of the boreholes and studying their productivity. The database consists of 154 technical data sheets on boreholes. The transmissivity and specific flow rate values vary from 3.53 x 10-6 to 1.30 x 10 m²/s and from 0.01 to 0.471 m²/h, respectively, ranging over 2 and 3 orders of magnitude. Nearly 20% of the structures have flow rates greater than 2.5 m³/h, and the depth of the boreholes varies from 46 to 98 m. The PCA performed on the characteristic parameters of the boreholes and the hydrodynamic parameters show that the productivity of the boreholes is influenced by transmissivity and specific flow rate. These results could contribute to a better understanding of fractured environments.