Diagnosis of a Small Dam Using Electric and Electromagnetic Methods —Case of Gonsé Dam (Central Region, Burkina Faso)

Abstract

Burkina Faso is a Sahelian country in West Africa that is faced with water resource mobilization problems. To develop vital sectors of its economy such as agriculture and livestock breeding, the country has elected to mobilize surface water through the construction of small earthen dams. With a stock of almost a thousand dams, the country is now faced with the problem of ageing structures, with embankments sometimes breaking during periods of high flooding. To deal with this situation, Burkina Faso has taken action to rehabilitate its dams. The planned maintenance work will, however, require prior diagnostics, which, given the number of structures to be examined, will constitute a real challenge. On this subject, geophysics offers detection methods that can be applied to the diagnosis of internal erosion problems that frequently affect earthen dams. In this regard, the study of the small Gonsé dam illustrates the contribution of geophysical methods to the detection of areas of water leaks through an earthen embankment. It demonstrates that, with the use of electromagnetic and electrical methods, it is possible to establish an initial diagnosis of structures through a routine of simple, rapid and non-invasive measurements.