Multifunctionele Klimaatrobuuste Waterkeringszones (KB-14-001-017, KB-02-002-088)

The objective of the project 'Multifunctional Robust Flood Defences' was to explore the potential of integration of the flood protection function with nature, landscape, and other values in a broad flood defence zone as an adaptation measure. In practice, the combination of multiple functions requires over-dimensioning and may thereby help to create a robust dike. The most important paradim shift associated with such a robust dike design is that overflow would lead to gradually increasing damage in the hinterland, while overflow of a traditionally designed dike is likely lead to catastrophic flooding due to collapse of the dike. Furthermore, the integration of functions would result in added value.

In this project special attention was being given to adaptation strategies for the Wadden region based on natural processes that could strenghten the ecological resilience of the area while facilitating sustainable human use. For the Wadden region a dike design that includes salt marshes was explored. Salt marshes form vegetated transition zones from land to water. Their shallow waters break incoming waves, reducing wave length and velocity, ultimately dissipating wave energy via friction with vegetation and the marsh surface. Salt marhes thus function as a natural flood defence. Salt marshes outside dikes can, to some extent, protect these hard defences against wave action and wave run-up.