Multiscale and multifactor sea-groundwater interactions in southwestern Mauritania

Coastal aquifers in semi-arid zones are particularly exposed to environmental changes because of their low annual recharge and the increasing anthropogenic pressure. This is case Trarza phreatic aquifer (SW Mauritania), which uppermost northern part great Senegalese-Mauritanian sedimentary basin. The interactions between Atlantic Ocean Tertiary-Quaternary have evolved considerably during last millennia these continuous concern nature location processes at work, intensity current consequences. In this vast region with a very flat topography, hydrodynamic geochemical observations still rare currently allow only main features recent history be reconstructed. analysis old data reveals that eustatic variations flood Senegal River were past most important factors equilibrium fresh water sea water, even far from present coastline. Today, anthropization, particular hydraulic developments urbanisation, adds complexity system. At more local scale, denser Nouakchott urban area or Diawling natural park provide better understanding dynamics.