Assessment of erosion and wave risk over coastal areas

The protection of coastal areas and the planning of their development need a continuous and reliable assessment of the risks deriving from waves and coastal erosion, not only in the interest of public safety, but also in order to allow the recreational use of the coast and the development of the relevant infrastructure. This is dictated not only by common sense and economics but often by legal requirements; local and planning authorities in some European countries must indeed produce and update hazard maps and storm scenarios for the whole length of the coast in order to comply with legal requirements and economical necessities; hence the need to develop operational procedures - including in this term not only formulas and software but also data collection and analysis techniques- to perform risk analysis over large coastal areas. The objective of this paper is to identify and clarify some of the problems related to wave actions and erosion hazards, with special emphasis on low and sandy shorelines; to outline the state of the art of operational procedures for the assessment and prevention of these hazards, and to present the research requirements aimed at improving the effectiveness and reliability of such procedures. The paper therefore concentrates on those aspects which are specific to flood defence and coastal protection measures rather than to the design of specific protection works.