BADA Ali Malloum^1,, MALOU Raymond¹, KODI Mahamat Mbâm¹, SOUK Allag Waayna¹

Lake Chad is an expanse of water that supports millions of people. Its excessive narrowing, or even its total disappearance, would lead to a large migration of populations, called climatic refugees. The collections of the dynamic monitoring of the quaternary phreatic aquifers over four years, the water level induced deductions provided data on the changes in the dynamic levels of the free water table due to the variation in lake water levels. The Lake Chad region, which is an arid to sub arid territory with a Sahel-Saharan climate, where water resources are under climatic and anthropogenic pressure. If we consider a desert climate zone where rains are rather scarce, we will have more stable groundwater. The aridity does not have a major impact on the resources of the dune sands aquifer, despite the almost total absence of rainfall. Surface waters have been severely reduced due to different periods of drought [1]. The study of the dynamics of the Quaternary aquifer by infiltration of rainwater and / or Lake Chad, provide us with clarification on the exchanges between the waters and the Quaternary aquifer. The theoretical and methodological approaches have given rise to spatiotemporal fluctuations of the dynamic level. The main observations observed, that there is a hydrodynamic variation of groundwater. The relationships between the water table and the surface waters could thus be clarified. This will eventually allow for alternative use of water resources.

narrowing, dynamic follow-ups, open water tables, water levers, water heights, quaternary aquifers, Lake Chad