Traditional interventions are expected to become difficult to sustain under high-end climate scenarios. Natural (BwN) solutions are better able to cope with varying wave conditions and rising sea-levels due to lower energy needs and costs associated to their implementation.
This reality has given rise to efforts to make greater use of ecosystem-based approaches to reduce risks from coastal storms. These approaches draw from the capacity of wetlands, beaches and dunes, biogenic reefs, and other natural features to reduce the impacts of storm surge and waves. In addition to providing engineering functions related to reducing risks from coastal storms, Natural and Nature-Based Features (NNBF) can provide a range of additional ecosystem services, including those supporting coastal ecosystems and communities.
A true systems approach to coastal risk reduction and resilience requires consideration of the full range of functions, services, and benefits produced by coastal projects and NNBF.
[Gentle music] [Gentle music] [Sound of waves] We have to protect ourselves from the water For centuries we have built high dikes But unfortunately this is often at the expense of nature. Recently things have been changing. Our understanding of the water system has improved and we can deal with flood risk in other ways. Hence, we have developed knowledge of building with nature We studied the use of vegetated foreshores for flood risk reduction and the certainties that are needed to implement this system. Such as more knowledge on the precise functioning of the forshores and new forms of governance involving nature conservation agencies and water managers. "So what if we broaden our scope iof we not only consider the water as our enemy but embrace the power of tides and waves in our favor.
Text- flood risk reduction using vegetated foreshores" How could that benefit us. [Music] "Text- Situation without vegetated foreshore In a situation without foreshores there is a high wave load on the dike during storm surges. " "Text- Situation with vegetated foreshore What happens in a situation with foreshores. The systems with mud flats and salt marshes attenuates the waves. Each natural foreshore is characterized by the same gradients. We study the wave damping effect of sediments and vegetation. The wave loads on the dike are lower. The dike can be less high and strong and original nature flourishes." For centuries the sea and rivers have transported small sand and clay particles. These particles are the building blocks of the delta. This natural process is still functioning. However, we fully don't understand how this works exactly. How does the coastal area develop. What causes sedimentation of the particles and under what conditions can new foreshores develop. If we understand the Delta, we can make better use of its natural processes. The vegetation traps sediment during each tide. With the rising sea level new sediment can settle on the foreshore and the foreshore height increases. There is no need for a repeated increase in dike height. In this way, nature can keep developing [Music] We allow centuries-old processes to do the work for us. We build a safe Delta with room for the value of nature which we can keep enjoying. [Music] Text: ecology bio-morphology hydraulics nature preservation governance [Music] Text: flood risk reduction using vegetated offshores [Music] Text- citg.tudelft.nl/be-safe [Music] [Music]