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11 th International Symposium for GIS and Computer Cartography for Coastal Zones ManagementFigure 1. Summary of the methodology for the V.I.E. index.Then, a weighting is assigned to each criterion and the sum of all the criteria defines the V.I.E. index. Each house will be coloureddepending on its mark and mapped using GIS.The study site: Noirmoutier Island (Vendée)The next step will be the application of the index to our study site: Noirmoutier Island. This island, located inVendée, is 49 km 2 and 500 m from the mainland at its narrowest passage. This low-lying island is a good example ofvulnerable territory. The north of the island is bedrock but the rest is mainly sandy, protected from the sea by asandy barrier from the northwest to the southeast. This sandy barrier is in retreat (Fatal et al., 2010; Debaine andRobin, 2012). Behind it are marshes that have been disconnected from the sea by dikes, for salt production and agriculture.Since 1960, the island has been particularly concerned with the development of urbanization for tourism. Manyhouses have been constructed in low areas, previously marshes. Most of the recent constructions are single-storey.Noirmoutier is sheltered from the sea by 24 km of dikes for 62 km of coastline. In terms of accessibility to rescueteams, Noirmoutier is a particularly interesting case because of its insular situation. A bridge connects the island tothe mainland and the main road crosses the territory from the southeast to the northwest. However, for the most part,the road runs through the lowest part of the island so that if there is a flood, the road will be impracticable for rescueoperations. Although Noirmoutier was not hit very hard by Xynthia, it is worth studying the potential effect of sucha storm on the island. Furthermore, a recent study has shown that a storm similar to Xynthia could generate 4.2billion euros of damage just on Noirmoutier Island, more than twice the cost of storm Xynthia (Garnier et al., 2012).Taking all these elements into consideration, Noirmoutier appears to be a very interesting case study with regardto its vulnerability to sea flooding, which is why we are applying the V.I.E. index to the island.ConclusionExposure and vulnerability to sea-flood risk will increase considerably in the future. It is essential to be able toevaluate and anticipate this vulnerability before another storm like Xynthia causes damage. This is the idea underlyingthe V.I.E. index. It is a tool which is easy to use, is relevant to many places and could have numerous applications,notably for decision-makers. For example, it could be useful to locate priority intervention areas or to recom-201