Researcher, CNRS, University of La Rochelle
Xavier Bertin completed a PhD in France on the dynamics of a tidal inlet/lagoon system. He spend then 4 years at the Portuguese National Civil Engineering Laboratory, first as a Marie Curie Postdoc and then as a Research Officer. In 2010, he returned to France as a CNRS Research Officer at the Joint Research Unit “Littoral, Environment and Societies”, part of the University of La Rochelle. Since 2013, he is leading the team “Physical Dynamics of Coastal Zones” and was promoted as a CNRS Research Director in 2017. His research concerns the hydro-sedimentary dynamics of coastal zones, with a particular interest on the dynamics driven by extreme events: storm surges, coastal erosion, marine flooding and infragravity waves. To address these scientific questions, he combines the acquisition and analysis of field observations (waves, water levels, currents, sediment transport and bathymetry) and the development and application of the 3D fully-coupled numerical modelling system SCHISM.
Talk on Thursday 6th June / Duo with Bruno Castelle
> Coastal erosion and storm-induced flooding
In a context of sea-level rise combined with local changes in storminess and more densely populated littoral zones, costal risks such as storm-induced flooding and coastal erosion are expected to be more frequent in the next decades. This lecture aims to give a broad overview of the main mechanisms that control storm-induced flooding and coastal erosion, combining key theoretical concepts illustrated by well-documented case studies.
We will see that coastal flooding mostly occurs at low-lying coastal zones, under the combination of a high tidal level and a storm surge. Storm surges correspond to a rise in mean water level, driven mainly by atmospheric perturbations (atmospheric pressure gradients and wind stress) but also by the dissipation of short waves near the coast. Finally, other less known phenomena such as infra-gravity waves can result in intermittent but substantial coastal flooding.
Shoreline change is controlled by a myriad of processes including, but not limited to, longshore transport, variability and trend in incident wave energy, fluvial sand supply, geological and anthropogenic settings. We will see that chronic shoreline change rates and the respective contribution of each process are essentially site specific, challenging generic sustainable adaptation measures.