ComCoast - Combined Functions in Coastal Defence Zones

In the project, five partner countries (Denmark, United Kingdom, The Netherlands, Germany and Belgium) work together to develop and implement innovative solutions for flood risk management in coastal areas. A central aspect of the project is to expand the single line of defence into an extensive coastal management system in the form of multifunctional flood defence zones.? This concept is applied in the partner countries in various different ways, to increase protection against flooding on the one hand and, on the other hand, to support the sustainable development of the coastal zones by integrating all the relevant user groups. In this, the aim is to create a combination of different spatial uses in the coastal zones.
In order to ensure a sustainable development of society, economy and ecology, the following points are covered:
The project is divided into six thematic sub-projects: 1. Spatial exploration, 2. Socio-economic valuation, 3. Technical defence concepts, 4. Participation, 5. Pilot areas of the partner countries and 6. Project management.
In Lower Saxony, as in the other partner countries, defence against storm surges plays a large role. Coastal defence is the most important protection function in the local coastal area, without which the life and work of the population would not be possible. In the German pilot area Nessmersiel, the aim is to strengthen this function of coastal defence in response to the new challenges, by developing sustainable strategies and concepts. Coastal defence in Lower Saxony already takes into account the latest scientific results of climate change impact research when developing protection measures, although new, probabilistic approaches are not considered for risk analyses. Nevertheless, there are constraints that will also present coastal defence with new challenges in the future, such as shortage of funds, poor building site conditions and greater spatial requirements than planned due to revised, last-minute requirements.
The following objectives need to be achieved:
In the German pilot area Nessmersiel, the aim is to evaluate and apply the methods, procedures and solutions developed in the project for the design of multi-functional coastal defence zones in a scenario-driven simulation. To this end, the illustration of possible spatial solutions that can be evaluated spatially in a geographic information system represents a good basis for discussing spatial coastal defence concepts.
The scenarios developed for Nessmersiel comprise specifications with regard to the societal, economic and natural environment. They take into account the possible demographic and economic developments as well as changes in land use over the next 50 years. Climate scenarios mainly include assumptions about climate change, sea-level rise and storm surge intensity.
The climate change will place increasingly higher demands on the defences along the North Sea coastlines. For example, where the sea-level rise coincides with a simultaneous subsidence of the land, this can result in an increased salinisation of the coastal region concerned. The traditional methods of coastal defence, usually single lines of defence, could reach their limits under these changing conditions.
The sensitivity of the floodplain ecosystems to the rising sea level is assessed. Sensitivity to erosion processes is comparatively high. The adaptive capacity of the floodplain ecosystems to compensate the sea-level rise by means of a land uplift (self-induced growth) is assessed. The adaptive capacity is comparatively high.
In the German pilot area Nessmersiel, there is no need for adaptation measures to the existing main dike, neither in the short term nor in the long term (in the sense of the time horizon for planning the coastal defences), since it meets the required safety standard proscribed by the Lower Saxony Dikes Act (Niedersächsisches Deichgesetz). Apart from this fact, however, it still makes sense to develop new coastal defence strategies.
Since the traditional methods of coastal defence could reach their limits under the changing climate conditions, new and innovative methods need to be tested and investigated. For example, the ComCoast concept envisages a more gradual transition from sea to land, with the aid of so-called "transition zones" The key premise for the use of such methods is that they guarantee the necessary safety of the population in the coastal regions from flooding. The transition zones provide benefits for both the environment and for the population through new land uses. The project illustrates the need for new and sustainable coastal defence strategies, so that future developments and new options can be taken into account in future planning.
The project develops individual adaptation solutions tailored to local conditions, with the aim of
Development of spatial use concepts up to 2050
In the development options for the coastal zones, ecological, social and also economic concerns are taken into account. This will support the development of sustainable alternatives to the traditional coastal defence methods and the identification of possibilities for the multi-functional use of the newly-developed coastal defence zones. The potential for conflict can be reduced by creating so-called "win-win" situations.
theoretical monetary valuation of the project approaches, multi-criteria evaluation of functions, cost-benefit analyses, total economic value (TEV based on use value, option value and existence value)
European Union, Interreg IIIB, North Sea Region
Rijkswaterstaat (Executive arm of the Dutch Ministry of Infrastructure and the Environment)
Province of Zeeland (Netherlands), Province of Groningen (Netherlands), University of Oldenburg (Germany), Environment Agency (Great Britain), ministry of Flanders (Belgium), Danish Coastal Authority (Denmark);
in Germany:
Institute for Chemistry and Biology of the Marine Environment (ICBM) at the University of Oldenburg, Lower Saxony Water Management, Coastal Defence and Nature Conservation Agency (NLWKN), Institute for Environmental Communication (INFU) at the University of Lüneburg
Rijkswaterstaat, Road and Hydraulic Engineering Institute (DWW)
Post-Office Box 5044
NL-2600 GA Delft
https://www.rijkswaterstaat.nl/english/index.aspx