Research director, CNRS
Bruno Castelle started a PhD in France on sandy beach morphodynamics. After a little more than 2 years working as Senior Research Assistant Griffith University (Australia), with both research and consultancy opportunities, he elected to return to France in 2007 to take up a CNRS research scientist position at the University of Bordeaux. He is interested in nearshore hydrodynamics and morphodynamics processes along sandy coasts on the timescales from a few seconds (wave motions) to decades including climate change effects. He relies on numerical and physical modelling, data-assimilation methods, observational techniques (Eulerian sensors, Lagrangian drifters) and remote sensing. He has been primarily leading research on rip currents, including beach safety and lifeguarding aspects, beach morphodynamics, wave climate variability and shoreline change. He co-authored over 110 peer-reviewed journal papers, currently serves as Associate Editor for Journal of Geophysical Research – Oceans and Ocean Dynamics and is the scientific coordinator the metropolitan and oversea French coastal monitoring network Dynalit which involves 22 universities.
Talk on Thursday 6th June / Duo with Xavier Bertin
> 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.