Characterisation of fissured aquifers in the semi-arid region of the mid-Atlas plateau (Oulmès, Morocco)

The Oulmès plateau (mid-Atlas in Morocco) is known for its groundwater resources in this semi-arid region. In the studied zone (approximately 80 km2), the mineral water of ‘Sidi Ali’ is exploited as well as the naturally semi-sparkling ‘mineral water of Oulmès’ which are main mineral waters marketed in Morocco. Their sources are located at less than four kilometers from each other. In the same time, the drinking water supply to the local rural populations is far from being sufficient, and even in some places non-existent. In addition the plateau is also the place where many fruit-bearing cultures have been undertaken for a few years. Irrigation and the use of pesticide and herbicide compounds as well as fertilizers could constitute threats for the groundwater quantity and quality and unpleasant consequences are expected for all dependent groundwater end-users. Thus, in this semi-arid zone, an acute problem of sustainable development arises in terms of groundwater quantity and quality. An extended study has involved data collection, measurement campaigns (piezometric levels, sampling & analysis of groundwater), shallow geophysical prospecting, pumping tests, building of a data base, estimation of the recharge spatial distribution and hydrogeological mapping. On the basis of this study, a better understanding is possible about the state and the particular hydrodynamic behaviour of groundwater in the fissured hard-rocks of this plateau. Results are expressed in maps providing explicit and useful information allowing future decisions which can be taken for the welfare of everyone and particularly for the local populations