Wave transformation on a rocky shore: from field work on re island to 3d modeling

Improving knowledge of the processes driving coastal flooding is a key issue in the era of climate change, especially for decision support of public policies and operational forecasting. From regional to city scales, different processes interact, such as tide, storm surge, waves, wave setup, or infra-gravity waves, and further depend on the area topography, bathymetry, sedimentology and external forcings. While sandy beaches have been the subject of many studies, rocky beaches are still poorly understood compared to sandy beach context, despite the important part of rocky French and world coasts. In this paper, we investigate the swell transformation on the rocky beach of Ars-en-Ré with an extensive field campaign and a numerical modelling with a 3D non-hydrostatic circulation model Symphonie NH (Marsaleix et al., 2019).