Storm surge disaster risk management: the Xynthia case study in France

In recent years, a series of catastrophic storm surges have occurred in Europe. The large number of fatalities and high material damage are mainly due to an increase in vulnerability and exposure to coastal flooding of hit regions. It is, therefore, necessary to intensify research activities in order to better understand this kind of disasters, to reduce their impacts and to reinforce risk management. This study describes the consequences of Xynthia windstorm that hit France in 2010: strong wind gusts, associated to high-coefficient tides and very low pressure, caused a phenomenon of storm surge in the Atlantic coastal area of France. Sea walls, lacking maintenance and originally built to defend agricultural land, were not able to protect houses. Fourty-seven people were killed, most of them from drowning, and direct losses amounted to more than 2.5 billion Euros. Around 10,000 people were forced to evacuate after the inundation of their properties. Uncontrolled urbanization was involved in the increase of stakes, as demonstrated by the fact that all the 29 victims in the city of la Faute-sur-Mer were living in houses built after 1980. The paper describes the event considering the aspect of increased vulnerability in the affected area, the lack of preparedness that exacerbated the final damage, the emergency response phases and the adaptation strategies adopted by the French Government after the disaster. We conclude that an attentive governance should include a balanced approach to risk protection, to reduce vulnerability and exposure.