Evaluating urban greening scenarios for urban heat mitigation: a spatially explicit approach.

Urban green infrastructure, especially trees, are widely regarded as one of the most effective ways to reduce urban temperatures in heatwaves and alleviate the adverse impacts of extreme heat events on human health and well-being. Nevertheless, urban planners and decision-makers are still lacking methods and tools to spatially evaluate the cooling effects of urban green spaces and exploit them to assess greening strategies at the urban agglomeration scale. This article introduces a novel spatially explicit approach to simulate urban greening scenarios by increasing the tree canopy cover in the existing urban fabric and evaluating their heat mitigation potential. The latter is achieved by applying the InVEST urban cooling model to the synthetic land use/land cover maps generated for the greening scenarios. A case study in the urban agglomeration of Lausanne, Switzerland, illustrates the development of tree canopy scenarios following distinct spatial distribution strategies. The spatial pattern of the tree canopy strongly influences the human exposure to the highest temperatures, and small increases in the abundance of tree canopy cover with the appropriate spatial configuration can have major impacts on human health and well-being. The proposed approach supports urban planning and the design of nature-based solutions to enhance climate resilience.

National assessment of cultural ecosystem services: Participatory mapping in Switzerland.

Previous studies assessed cultural ecosystem services (CES) at the local scale but often ignored them in national assessments. This paper explores CES relationships in Switzerland using web-based participatory mapping. We identified the spatial relationships between CES, the drivers of negative change and solutions to mitigate it. Results indicated that CES tend to have positive spatial relationships, although not always significant. A proxy-based approach supported the findings that the provision of heritage and inspiration services decreased along the urban-rural gradient while others increased. Participants located more CES close to their residence, but acknowledged their presence in distant alpine regions. They reported that better planning and stricter implementation of policies were necessary to refrain CES loss. According to respondents, there might be a density threshold to ensure sustainable supply of CES. Although mitigation measures were specific enough at the national scale, they remained too broad to be applicable at the local scale.