Urban Wetlands and Riparian Forests as a Nature-Based Solution for Climate Change Adaptation in Cities and Their Surroundings

Abstract

Wetlands and riparian forests belong to the most productive, but also the most vulnerable, ecosystems in urban regions and cities due to their complex watershed system, often very high biodiversity and the pressure from urban land use and surface sealing. Wetlands and floodplain forests are often highly valued recreational areas, providing many benefits for urban dwellers, such as fresh air, moisture, oxygen and biogenic essentials as well as many cultural and place-based values. Wetlands and riparian forests are very efficient spaces for water and matter regulation, pollutants fixation and flood water retention. Thus, particularly for dense urban areas, they represent almost perfect nature-based solutions for risk mitigation and adaptation concerning both climate extremes: flood and drought. Moreover, they can serve as a buffer against high air temperatures and provide wetness during heat waves. However, urban wetlands and riparian forests are often endangered by urbanisation pressure, land take for construction purposes and pollution. This chapter provides arguments that urban wetlands being a nature-based solution for cities facing climate change and presents design options to expand and even create such wetlands in cities where remnants are no longer available.

Not Simply Green: Nature-Based Solutions as a Concept and Practical Approach for Sustainability Studies and Planning Agendas in Cities

“…As stated by variety of stakeholders, the long-term benefits are not clearly defined for them and for citizens, which pose an additional task for the city to visualize the effects of projects regarding the long-term benefits [7,9,11,13,17,19,37]. As our previous research shows, very few trade-offs were identified so far, such as eco-gentrification, ecosystem disservices, etc.…”

“…The second group of challenges includes those caused by environmental risks connected to climate change-i.e., flooding and heat waves. The last big floods in Germany (stemming from the Elbe, Oder, Mulde, and Rhine) drew attention to the fact that technical or manufactured water protection is not 100% effective, particularly when taking climate change and longer heavy precipitation events into consideration [16,17]. Moreover, with its hazardous bursting of large dams, the last Elbe flood in Germany in 2013 made it very clear that the failure of technological solutions can result in enormous damage and casualties.…”

“…This is because the capacities of technological solutions are enormous in terms of how much water they can hold back, which is much more than any NBS. In this regard, when restoring and maintaining the functionality of wetlands and floodplains or when revitalizing large and smaller rivers NBSs manifest a continuous and more natural inflow and distribution of rainfall water in a larger area and have been shown to improve protection against catastrophic flood events along rivers and coasts [17]. The city currently faces major challenges ( Figure 2), including large-scale social, economic, political, and ecological changes over the last 150 years that have been caused by industrialization, the city's socialist past, post-industrial development with active out-migration, and the side effects of rapid development (from a shrinking city to becoming one of Germany's most rapidly growing cities in only a few decades).…”

“…This is because the capacities of technological solutions are enormous in terms of how much water they can hold back, which is much more than any NBS. In this regard, when restoring and maintaining the functionality of wetlands and floodplains or when revitalizing large and smaller rivers NBSs manifest a continuous and more natural inflow and distribution of rainfall water in a larger area and have been shown to improve protection against catastrophic flood events along rivers and coasts [17].…”

“…Investing in restoring, protecting, and enhancing ecological functionality and ecosystem services through the implementation of different NBSs is not only ecologically and socially desirable [16,17,31], but also, as the contribution has shown, the multiple benefits obtained from NBSs have a great value for a large number of beneficiaries in the city of Leipzig.…”