Diagnostic préventif de la vulnérabilité des constructions résidentielles pour leurs occupants face au risque de submersion marine appliqué à l’île de Noirmoutier (Vendée, France)

Abstract

Abstract : Storm Xynthia (2010) was responsible for the death by drowning of 41 people along the French Atlantic coast. Review of the event highlighted how housing buildings increase human vulnerability. Consecutively, French government decided to demolish the most dangerous houses. Nevertheless, it was applied only on the Xynthia’s most impacted areas. However, other vulnerable territories to coastal floods are identified along French coast. The assumption of this work is to provide a preventive diagnosis of vulnerability of housing building for people on Noirmoutier Island. This territory has similar features than those impacted by Storm Xynthia and was severally struck by coastal floods event in the past. Using V.I.E. index methodology, results show that the four towns of the island are not equally exposed to coastal flood. 46 % of housing buildings of the island could potentially be flooded but there are differences between towns from 28 % to 76 %. But towns which have the most important part of dangerous buildings are the one where urbanization is close to dikes. All in all, Noirmoutier Island is less vulnerable than La Faute-sur-Mer (29 deaths during Xynthia) but it confirms that closeness to dikes increase vulnerability. This diagnosis is a way to promote adaptation measures in order to prevent consequences of future coastal floods on the island.

Keywords

• vulnerability
• coastal risks
• storm Xynthia
• coastal flood
• residential buildings
• vulnerability index