Sedimentary hydrodynamics of a sandy bay under macrotidal conditions (Saire Bay, France)

Identified as one of the most vulnerable environment to the impacts of sea-level rise, the morphological and hydrological diversity of coastal areas complicates their study. To understand their evolution, it is essential to characterize their current morpho-sedimentary distributions and processes. Morphologic interpretation, from LiDAR data, coupled with grain-size and geochemical analyses of 200 samples, subsequently interpreted with statistical tools (PCA), allow us to determine the pattern of sedimentary transport of Saire Bay (Normandy, France).Even if the area is mainly dominated by tidal currents, the original morphology of Saire Bay highlights an uncommon complex circulation on a sandy tidal flat. Sedimentary land-sea exchanges, induced by tidal current, do not occur through the river Saire network in the north, but in south, along a less apparent secondary channel. Results provide an essential base to better understand the evolution of the coastline.