Etude expérimentale de La dynamique hydro-sédimentaire des étangs de la Brenne et impacts sur les cours d'eau.

Abstract

With over 500 000 (Bartout et al, 2013) ponds, France is considered hydraulically as the richest country in Europe and in the world, although all limnic researches around the world prove that areal water is de-oxygenated in the hypolimnion strata which tends to become eutrophic. But no one of these reseaches has approached the actual ponds’ issues and their physico-chemical states. Our study will be focused on the biggest preserved pond in France which is la Brenne. It is located in the centeral region. Its first investigation shows us a high concentration of heavy metals in water and sediments leading to Cadmium. This geochemistry abnormality requires a thorough investigation in the water-sediment interface because it could be a potential source of contamination. We will try to drill the mystery of this geochemistry abnormality by using a methodology axed on two principal thematic researches. The first fondamental one is based on identifying the pond’s buttom dynamic, physical bioturbation and resuspension which control chemical transformations that happen in the water-sediment interface during the prime diagenetique’s phases and comprehension of the part of organic matter in these transformations. After that we will investigate the fluvial system linked to these ponds to be able to see if they are concerned by the pollution of the Brenne ponds or not.