ABSTRACT

An extensive study was made of the hydrogeology of the region around Zouerate in the north-western part of Mauritania. This area consists of two main zones: the Archaean basement in the west and the margin of the Taoudenni sedimentary basin in the east. The geometry of the aquifers in the Taoudenni basin was deduced by a combination of different techniques including: refinement of the geological map using remote sensing, interpretation of aerial magnetometric data and construction of a hydrostratigraphic log. A survey of 624 groundwater points, including GPS levelling, was conducted. It became apparent that a few sebkhas are the main regional discharge zones. To estimate the fluxes, a 2D regional model was constructed and calibrated. It allowed a comparison of different recharge scenarios and may be used to run long-term simulations. A great deal of uncertainty remains in the model results, especially concerning the recharge area distribution.