Erosions, dépots et transits sédimentaires associés dans le bassin de Marennes-Oléron

Managing sediments in the bate de Marennes-Oleron (Atlantic coast of France) can be achieved providing particulate fluxes at the scale of the basin are available as well as tidal and meteorological conditions during which major transports occur A sediment dynamics model accounting for tide- and wave-induced sand and mud transport has been applied to the Pertuis Charentais area Consolidation of pure mud and mixtures of sand and mud is accounted for The model validation is achieved by current and turbidity measurements, local altimetric surveys during one year and pressure measurements for waves on the tidal flat An asymmetry between eastern and western halves of the bay is observed on turbidity signals in agreement with a residual circulation from north to south This flow generates a net fine sediment transport towards the south A part of it is deposited within the bay According to the model the eroded area east of Antioche inlet would be the main source of this southward flux this feature has to be validated The flux can be inversed during storms, but for a short duration However waves are dominant in the resuspension process Last the variability of sediment nature is demonstrated with the model at different time scales in relation with tidal phases and storm.