Houses damaged by dune erosion at Tranche-sur-Mer, in the wake of the Xynthia storm (Vendée, W France, 2010). © BRGM - Rodrigo Pedreros

Coastal and coastline risks

BRGM is closely involved in furthering knowledge on coastal risks and their management in the context of climate change. It is also involved in monitoring coastline change, through the Coastline Observatories in mainland and overseas France.

BRGM conducts research and expert studies on the main coastal risks at different scales: individual events, multi-annual, local and global.

  • Coastal erosion;
  • Marine submersion of low-lying zones, as a result of hydrometeorological events such as storms and hurricanes, or by tsunamis.

Because these phenomena are occurring in the context of climate change, BRGM also investigates the consequences of global changes such as sea-level rise or changes in wave and current patterns.

Assessing potential hazards and vulnerability to reduce risks

The aim is to reduce coastal risks and relies on several types of activities:

  • Improving knowledge and tools for quantifying these risks, in particular by:
    • modelling water levels, from the open sea to the coastline,
    • modelling currents and waves during extreme weather events (storms and hurricanes),
    • in the case of seismic or gravity-related events, tsunamis are modelled from their formation up to their propagation to the coast, with associated submersion events,
    • statistical analyses,
    • construction of a reference tsunami database compiling the history and characteristics of tsunamis observed in France and along its seaboard.
  • Improving knowledge on coastal erosion through monitoring data (observatories), available databases and modelling;
  • Vulnerability analyses of the physical environment and the environmental, economic and human issues that arise;
  •  Risk analyses and mapping, for example through statistical analyses of potential risks or other innovative approaches (e.g. risk thresholds and “reverse” methods);
  • Defining coastal land use scenarios that could reduce risks.

Taking climate change into account

BRGM research and expert studies on coastal risks take into account the impacts of climate change and developments affecting the coastline (increasing attractiveness for human activities). The aim is to meet the need to predict coastal zone impacts (permanent submersion, coastline retreat, etc.).

BRGM - 3 avenue Claude-Guillemin - BP 36009 45060 Orléans Cedex 2 - France Tel.: +33 (0)2 38 64 34 34