This thesis aims at increasing the general knowledge on sediment dynamics of intertidal flats in the Marennes-Oléron Bay, according to physical, biological and anthropogenic factors. The conducted research is compound of three complementary studies: (1) a study of sediment behaviour through applied rheophysics on intertidal superficial sediments; (2) a hydro-sedimentary study based on identification of the forcing action (physical, biological or anthropogenic) on the intertidal flat stability over several time scales (from the event to several months); (3) a specific application of the model SiAM-2DH to the Marennes-Oléron Bay. The surface sediments shows a mechanical behaviour that mainly depends on the fine fraction for a composition that contains up... |