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Climate research

Nature can help when extreme weather hits

Floods, heat waves, storms and droughts are becoming more common as temperatures rise, so we need to find new ways to protect our cities and communities. Nature itself offers many solutions, and we must learn to make better use of them, say the researchers behind a new elite center for climate research at SDU.

By Birgitte Svennevig, , 2/21/2023

Our cities and rural areas cannot always cope with all the water from cloudbursts, prolonged rain and rising sea levels. Cellars, sewers and harbor piers are flooded, and it is obvious to suggest dikes, larger sewer pipes and rainwater basins as solutions. 

But we can get more out of choosing solutions that involve nature itself; these are the so-called nature-based solutions.

The researchers behind SDU's new elite center, Aqua-NbS (Elite Centre of Aquatic Nature-based Solutions for Climate Change adaptation and mitigation) know this, and now they have been granted DKK 10 million to pave the way for nature-based solutions to be further scaled up in Denmark. 

The elite center will follow 11 demonstration projects and also gather input and experience from the authorities, landowners, volunteers and NGOs involved. 

Climate research at SDU

SDU Climate Cluster's mission is to contribute to climate neutrality by 2050 at the latest.
That is, a society where no more greenhouse gas is emitted than is absorbed.
SCC will contribute to this through interdisciplinary climate research and for that, SDU has allocated DKK 96 million. 

- With that, we can create guidelines so that you can really boost the climate effort and get these nature-based solutions scaled up, said head of Aqua-NbS, Cintia Quintana, who is an expert in aquatic ecology and associate professor at the Department of Biology. 

The funding comes from SDU Climate Cluster, led by professor in climate changes and glaciology, Sebastian Mernild:  

- This is an exciting and important project, considering that temperatures will continue to rise in the next decades, and that consequences will be significant. In that light, we need to learn more about nature-based solutions to adapt to and mitigate future climate challenges, he said.  

With that, we can create guidelines so that you can really boost the climate effort and get these nature-based solutions scaled up

Cintia Quintana, associate professor and head of Aqua-NbS

An example of a nature-based solution is to allow vegetation and underground absorb excess water instead of collecting it in, for example, a concrete basin or letting it flow over concrete and asphalt directly into waterways or the sea. 

Such areas already exist in nature; it's the salt marshes. The soil of salt marshes can absorb water and thus prevent flooding. Water seeps only slowly through the salt marshes and their small channels and therefore it flows slowly into fjords and creeks. Along the way, particles and nutrients from the water are absorbed by the salt marsh, so that the water is cleaner and less nutrient-rich when it reaches fjords and creeks.  

- Salt marshes are a classic, nature-based solution. We have removed many of Denmark's original salt marshes, but we can restore them – and should also do so in more places, because they can really help, Cintia Quintana believes.

New fjord landscape in the town center of Vejle 

In the Danish town Vejle, where there is a risk of flooding from the fjord, the municipality is working on protecting the low-lying town center from flooding. One of the ideas is to establish a nature-based protection facility, that runs as a wide zone between water and land. It will not only protect the town from flooding, but the aim is also to increase the biodiversity under and above the water.  

By creating a membrane facility, made of mainly nature-based materials and with great variation in surface and texture, the construction may create new biotopes for plants and animals.  

- The core of the idea is to expand the zone between water and land and create a bufferzone that works along the same principles as the original salt marshes. If this project can also contribute to more biodiversity in our inner fjord, it is a bonus, said Lotta Tiselius, an architect and project developer in Vejle Kommune, and continues:

- On top, the citizens of Vejle also get a new recreational area, where they can experience the dynamics of the sea up close.


SDU's new elite centers for climate research

    The SDU Climate Cluster has established the first two of five elite centers for climate research.

    • Aqua-NbS (Elite Centre of Aquatic Nature-based Solutions for Climate Change adaptation and mitigation) will be established at the Faculty of Science. Also participating are researchers from the faculties of Business and Social Sciences, Engineering and Humanities.
    • SOLEN (Elite Centre on Solar Energy Conversion and Storage) will be established at the Faculty of Engineering. Also participating are researchers from the faculties of  Science, Business and Social Sciences,  and Humanities.
    • Each center is granted up to DKK 10 million for a four-year period.
    • The centres must ensure that interdisciplinary research is carried out at a high international level at each of SDU's five faculties, and that they support SCC's mission to contribute to climate neutrality by 2050 at the latest. 

Just outside Odense, there is an example of another kind of nature-based solution. It is very practical and very simple and easy to get started with: Do not use more asphalt than is absolutely necessary on the roads and leave a layer of pebbles and vegetation out on the sides. 

- That is a nature-based solution that allows the seepage of water and the filtering of pollutants, explains Cintia Quintana. 

Many local initiatives around Denmark can be defined as nature-based solutions, but they are not always connected as a larger system. 

Are there other solutions than the classical concrete wall? 

- The optimal nature-based solutions consist of coherent measures, where you plan the water's path from the catchment area through catchment basins and on into the waterways. It will be one of our tasks to create guidelines for this, said Cintia Quintana. 

Lotta Tiselius from Vejle Kommune adds:  

- It makes a lot of sense to develop the future’s nature-based solutions in towns and municipalities in collaboration with experts like Aqua-NbS. We don’t really have that many good examples of nature-based solutions yet, especially not in urban coastal environments, which is what our project is about, she says and continues:

We try to find other solutions than the classical concrete wall to protect us against the water – for that we need to work with experts in especially biology over and under the water. For Aqua-NbS, there is a value in seeing how demonstration projects are planned and constructed in places where they have a purpose.  


10 of the 11 demonstration projects that Aqua-NbS is following closely

1. Floating islands 
Can you use floating islands in rainwater basins to clean the water of dissolved substances such as nutrients and metals and at the same time increase biodiversity? VandCenter Syd, the University of Copenhagen and SDU are investigating. 
2. Climate-robust borderland 
In the Danish/German border country, small and medium-sized companies get expert knowledge to make the region more climate-robust in the NEPTUN project, which is financed by Interreg Deutschland-Danmark with funds from the European Fund for Regional Development. 
3. Holistic road work 
Cars need to be able to pull over, but it does not have to be on asphalt. Asphalt on the centre of the road is often enough, and as for the sides of the road, they can be covered with pebbles and low vegetation. In the cities, road sides can be turned into flower beds. 

4. Better water environment in Odense Fjord 
Authorities, companies, researchers and organizations have come together to restore the aquatic environment in Odense Fjord and the fjord's catchment area by, for example, planting new eelgrass beds. The project is called the Odense Fjord Samarbejdet. 

5. Education in climate-resilient cities 
The International Urban Resilience Academy at SDU offers network activities and training for researchers and practitioners, based on new knowledge from Aqua-NbS. 

6. New salt marshes in the suburbs of Odense  
Seden Strand is a suburb of Odense and an area where both residents and agriculture are threatened by floods. The goal is that, by converting from dykes to salt marshes, the risk of flooding can be reduced. 

7. The Nordic salt marshes 
NORDSALT is a research project based at SDU that investigates the importance of the Nordic salt marshes for climate regulation. 

8. Flood protection in Vejle 
The membrane” is a project, contributing to the flood protection of low-lying areas in the town of Vejle. It is a nature-based and recreational facility along the road Tirsbæk Strandvej, not only securing protection but also contributing to an increase in biodiversity below and above water. The boundary between water and land is expanded to become a zone that thrives in both dry and wet times. 

9. Healthy Vejle Fjord 
Restoration of the ecological condition in Vejle Fjord. Restoring eelgrass beds will contribute as a demonstration of the benefits on restored biodiversity of eelgrass and associated ecosystem services.   

10. Gyldensteen coastal lagoon 
In 2014, the dykes at Gyldensteen on the north tip of the island Fyn were removed so that the sea could return to the low-lying fields. This re-established the original wetlands and today, Gyldensteen functions as a demonstration project of what happens when sea levels rise and flood low-lying land.  

Meet the researcher

Cintia Quintana is associate professor in aquatic ecology at the Department of Biology. One of her main research areas is how we can use nature to solve the problems caused by climate change.


Editing was completed: 21.02.2023