Coastal Risk Management Modes: The Managed Realignment as a Risk Conception More Integrated

Land managers assess the risk by evaluating the probability of hazard occurring and likely damage that would occur to economic assets. There are two types of hazards. The first is caused by wave action, near-shore current and wind effects; which imply erosion and its associated risk of flooding. The second is increased by physical structures that have been built with the aim of protecting the coastline. Storms can induce the destruction of coastal protections as dunes and promote the sea submersion. Sea submersion is a temporary flood of coastal area due to the sea and needing extreme weather conditions. Given the importance of biodiversity and attractive nature of coastal areas, they present different stakes. There are socio-economic stakes as people, amenities, activities and infrastructures. And in the same way, there are natural stakes and cultural heritages as natural areas and historic building. To anticipate coastal risks, coastal management has always been a major question for land managers. During the XIXth century, Victor Hugo himself has made speeches to outline the vulnerability of coastal areas to these hazards (Hugo, 1846). For a long time, hard structures were built to hold the line and to provide high level of protection to population. These options more easy to develop were usually used because of absence of knowledge. But in the last twenty years, new approaches to manage coast have been developed. This shift of coastal management by the decision makers has depended on the appearance of the Integrated Coastal Zone Management (ICZM) concept too. The ICZM is originating from the US and adapted in France via Europe. It replaces a protectionist policy, long based on a naturalistic approach. Taking consideration of the economic, sociological, biological concerns and the democratic, educational and political ones as well, with in addition the relationships between the various partners involved, is a land management way that cannot be ignored these days of sustainable development (Bawedin, 2009). One of these new approaches to manage coastal areas corresponds to the managed realignment (MR). Different cases of managed realignment exist and constitute a heterogeneous set. Indeed local context differences as the type and the importance of stakes and hazards, of sites topography, but especially of coastal management conceptions into public policies, induce an important diversity of M.R. cases. Thus in a context of thoughts