Science et changements planétaires / Sécheresse


Contribution of electric and electromagnetic geophysics measurements to the study of the future Samendéni dam: identification of faults and dolerite intrusions Volume 20, issue 2, avril-mai-juin 2009


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Laboratoire d’hydrogéologie Université de Ouagadougou 03 BP 7021 Ouagadougou Burkina Faso

In a context of persistent dryness in Burkina, the hydro-agricultural dam construction remains an absolute necessity. The future Samendéni dam intended to contain 1 billion cubic meters is made of fine sediments of sandstone. The site is at a few hundred metres from a major fault line, a dextral and strike-slit fault line almost 60 km long. The electric and electromagnetic MaxMin show two dolerite intrusions and many faults crossing the dam. The most important faults are those which bring the intrusions of dolerites and their overhanging rocks into contact. The existence of the faults poses a problem concerning the future staunchness and stability of the dam. Filling the reservoir could, as well, increase tension in the strike-slit fault located upstream (induced seism).