Abdoul-Kader Traoré¹, Césard Millogo^{2, 3,}, Issan Ki^{2, 3}, Wilédio Marc-Emile Bonzi^{2, 3}

This hydrogeological study, carried out in the commune of Tenkodogo (Burkina Faso), aims to gain a better understanding of the productivity of aquifers using the hydrodynamic parameters of existing boreholes. The geological and climatic context of the region, characterized by a crystalline basement and a tropical climate, presents major challenges for water resource management, particularly due to low rainfall, high evapotranspiration and aquifers with low rechargeability. The analysis covers 165 boreholes, for which various data were collected, such as depth, thickness of alteration, fracturing, flow rates and local geology. The results show that 73.33% of the boreholes are productive, with a significant proportion of high-flow boreholes (> 5 m³/h), reflecting the relative abundance of groundwater resources in this region. The study highlights the importance of alteration thickness and fracturing in determining borehole flow rates. In particular, the best productivity is observed in zones with alteration between 15 and 40 m and fracturing between 20 and 50 m. The analysis also shows that boreholes drilled in geological formations such as granites, tonalites and leptynites are the most frequent and have a wide range of flow rates. The results of this study provide crucial information for the sustainable management of groundwater resources in Tenkodogo, by identifying the most promising areas, such as the leptynites, for new boreholes and optimising the use of available aquifers. This work will thus contribute to our understanding of crystalline basement aquifers and to improving drinking water supplies in this region of Burkina Faso.

Groundwater, basement aquifer, productivity factors, flow rates, Tenkodogo, Burkina Faso