Nature enriched structures
Low-lying delta areas often use dikes and other hard coastal defence structures to protect the land against flooding, and harbour structures such as piers, docks and jetties for transport purposes. On top of their primary function, these structures are often used by a variety of plants and animals for growing, reproduction, nursery and feeding.
Coastal defences can be improved in this respect by adapting traditional coastal engineering structures to this ecosystem function. This may even have a positive effect on the structure itself: extra dike stability and wave damping may be provided by deliberate introduction of vegetation such as saltmarsh, reeds, shrubs or trees. Eco-friendly revetments can contribute to the ecological value of a dike and – depending on their location and design, dikes may also host a range of other functions such as living, meadow-land and recreation.
Here we consider the following types of structure enrichment:Soft Eco-Levee: Replacing
Sometimes, fully 'green solutions' are not feasible due to high wave energy and/or limited space. Here, green-gray hybrid solutions may form an interesting alternative. In addition to a traditional dike, vegetated foreshores can help to reduce wave height and stabilize the sediment. Under certain conditions the dike’s crest can even be designed lower than in a traditional design due to the wave-attenuating effect of the foreshore. In addition, the ecological value of grey infrastructure can be improved by slightly adapting them to form a habitat for a variety of plants and animals. These 'nature-enriched structures' or 'rich revetments' are applied in harbours as well as along sea dikes.
|Foreshores in freshwater environments||Enriching revetments||Creating hanging and floating structures|
Hybrid solution to replace the traditional 'hard-cover' design
. Vegetated foreshores in freshwater environments have the ability to reduce wave impact, provide en enhance the natural value.
This concept aims to create
in the intertidal and subtidal zone of
such as seawalls and harbours.
Rich structures are small-scale structures that provide habitat for organisms. Examples are floating marshes and pile and pontoon hulas. The structures are easy to apply and suitable even when available space is limited.