Nature-based solutions in designing sustainable urban development strategies – how to generate appropriate information?

Nature-based solutions are considered to be an important alternative to technical solutions when it comes to sustainable landscape and urban development. They are considered to make best use of ecosystem functions that contribute to reduce risks such as flooding and enhance regulative services such as cooling effects in the summer or filtering pollutants to increase air quality. However, for including such solutions in urban or landscape development, knowledge on the respective functional contribution of different land coverages needs to be processed in a way that it can inform even untrained stakeholders in designing and agreeing upon scenarios. Nature-based solutions in an urban context cannot exclusively incorporate “natural ecosystems” but need to consider equally opportunities for more sustainable building and settlement styles, including e.g. green roofs, green facades or the provision of niches for bird nesting / housing of bats.
In the city of Halle, Saxony-Anhalt, Germany, we studied how to introduce the concept of hemeroby in urban planning for informing on potential threats for human well-being through urban densification. The underlying assumption was that hemeroby that expresses the degree of human impact on an (eco)system (Steinhardt et al., 1999)and thus can be understood as a measure for disturbances (Fanelli and Testi, 2008) indicates the degree to which a specific land coverage can contribute to the overall (ecological and hydrological) functioning of an urban area. We hypothesized that hemeroby could be a meaningful approach to translate diverse data sets (ATKIS, CORINE, Orthophotos) into an agreed standard to express (a) the functional values of different urban land coverages (e.g. Angold et al., 2006; Walz and Stein, 2014; Wania, 2007) and (b) to inform on capacities (or risks) for providing urban ecosystem services.
We started developing translation routines that combine land cover information with a terrestrial assessment of the status of typical urban ecosystems and the built environment considering how far these different land cover types add to sealing / fragmentation of green areas or to connect habitats, provide niches and include non-sealed space (Czaja, 2016). Based on this urban hemeroby map, we proceeded with the derivation of an urban ecosystem services map. This map is subsequently used as a basis for scenario modelling when it comes to best recommendable opportunities to reduce negative impacts of urban development on human well-being.
Further tests in other cities are planned to explore how reliable and transferrable the approach is to inform urban planners and citizens in participatory planning processes.