OSUG - Terre Univers Environnement


Hydrologcal Processes for Vulnerables Water Resources


Évolution de la pluie cumulée depuis le début de l’année aux stations de Niamey Orstom, Banizoumbou et Wankama (Niger) et comparaison avec la moyenne inter annuelle des périodes sèches (71-90) / humides (51-70). la description In the Sahel the ponds are filled by surface runoff and are preferential areas for infiltration. Some turns into a wet lands because of the rise of the water table. Parflow/CLM simulation of the upper Ouémé catchment in Bénin (16000km²) Electromagnetic prospection in Bénin pedological fault to measure water transfers in the unsaturated zone Eddy Covariance sensors to measure evapotranspiration In Benin, 40% of pumping well are not productive Soil samples to characterize hydrodynamical properties Aquifer transmissivity measurement of an in Bénin.


With regard to future demographic and climatic changes, the rational management of water resources (aquifers, surface waters) is one of the major challenges of the next century, especially in environments where they are rare or difficult to exploit. These resources are located in the Critical Zone. They are particularly vulnerable when they are subjected to high anthropogenic pressures (irrigation, pollution, land-use change etc.), and/or climatic pressures (insufficient or decreasing recharge, modification of rainfall extremes, increased evapotranspiration, change in infiltration and superficial moisture). The spatio-temporal dynamics of these resources are conditioned by the spatial distribution of precipitation, but also by the spatial redistribution of water, whether natural (river, underground transfer) or anthropogenic (pumping for adduction or irrigation ). These transfers, the continental part of the water cycle, also affect hydrological hazard and interactions with the atmosphere.

In this context The PHyREV team is interested more specifically in complex environments where hydrological responses are the result of the interdependence of many hydrological , but also eco-physiological and micro-meteorological processes. The studied scales ranges from a few hectares, to a few km² or cover regional scales such as the Sahel or the entire West Africa.

Scientific questions :

The scientific questions of the PHyREV team concern on the one hand scaling issues in hydrology and on the other hand the interactions between the surface processes and the recharge of the aquifers:

• How can we bring responses for the future of water resources (aquifers, surface water) at a regional scale based on knowledge of the physical processes identified at the lower scales (plot, slope, elementary catchment)?

• What are the interactions between surface processes and recharge of aquifers and to what extent is it necessary to take these interactions into account in order to predict the availability of water resources and hydrological hazards?