Vegetation in salt marshes improves coastal protection from storms

Published: 2 October 2014

For the first time, large-scale tests have shown that salt marshes act as a buffer zones and attenuate waves, even in extreme conditions such as storm surges. In combination with vegetation, they reduce waves by approximately 20% over a distance of 40 metres.

This means that dikes behind salt marshes can be a lot lower and cheaper. The results of the tests, which were conducted in the Large Wave Flume in Hannover, have been published in the leading scientific journal Nature Geoscience.

2977[1]

Bregje van Wesenbeeck, a specialist in nature-based engineering at Deltares and a co-author of the article: ‘Our computer models were already telling us that marshes can attenuate waves in extreme conditions as well, but scale testing and field measurements were confined to small waves. In Hannover, we looked at what happens to marshes during storms.’

It emerged that, even in these conditions, marshes remain functional and intact. Bregje van Wesenbeeck: ‘There is no vertical erosion, even though some of the vegetation is lost.’ Bregje believes that the experiments were a major step forward in terms of quantifying the role of ecosystems in flood prevention.

Click here for the article in Nature Geoscience