International symposium - Aquifers Systems Management - 30 may-1th june 2006, Dijon, France Colloque international - Gestion des grands aquifères - 30 mai-1er juin 2006, Dijon, France

DARCY 45 Etude hydrogéologique et modélisation mathématique du système aquifère du bassin sédimentaire de Taoudeni au Burkina Faso
DEROUANE Johan 1 & DAKOURE Denis
2

1 MRW DGRNE Division de l’Eau, Jambes, Belgique, j.derouane@mrw.wallonie.be 2 MAHRH DGAEP Programme VREO, Bobo-Dioulasso, Burkina Faso, vreo@fasonet.bf

Abstract
The south-west of Burkina Faso shares with the south of Mali a regional aquifer system that forms part of West Africa’s large sedimentary basin of Taoudeni. With a surface area of around 40,000 km? inside Burkina Faso, and a depth that can reach more than 2,000 meters, this sedimentary aquifer system provides most of the water resources exploited for human (drinking water) and economic (mainly agriculture) needs in the country. In a critical semi-arid context characterised by the notable decrease in pluviometry observed in the last 40 years, and by a demographic explosion resulting in a highly increased need of water for human consumption and for economic development, the management of this important groundwater resource has become a priority not only for the Burkina Faso authorities, but also for the international community. A hydrogeological multi-disciplinary approach, combining amongst others stratigraphy, hydrodynamic field-data, geochemistry and isotopic techniques with geological and hydrogeological modeling, is being implemented to improve the knowledge of the aquifer system and the efficiency of its management. While geochemistry and isotopic techniques performed in the studied area do not provide convincing elements to consider the existence of individualized aquifers inside the identified sedimentary geological formations, the question of vertical hydraulic continuity over the whole part of the sedimentary basin in Burkina Faso still