Integrating Spatial analysis, Ecosystem Services and cost analysis for Nature-Based Solution (NBS) planning in the urban context

Many stresses, related to local and global conditions, affect cities, like climate change and urban heat islands. Nature-Based Solutions (NBS) are suggested in urban systems to mitigate climate change effects, supporting the transition to sustainable development and improving citizens’ well-being, according to the advantages of providing Ecosystem Services (ES). Despite the great attention to implementing NBS in urban systems, cities worldwide face critical issues in investing in NBS. These criticalities are mainly due to the lack of a comprehensive evaluation framework supporting decision-making to integrate NBS in urban planning. The proposed evaluation method is a multi-step approach to firstly identify the most suitable intervention area, and secondly, provide an overall evaluation of the cost and benefits of NBS interventions. The proposed framework is applied to the city of Milan to identify the most urgent area for NBS implementation, according to multidimensional vulnerability maps related to social, economic and environmental stresses. Three interventions have been compared with the business-as-usual scenario and evaluated according to the costs and benefits provided by ES to select the most preferable one according to a multidimensional perspective. The novelty of the proposed framework concerns the application of monetary and non-monetary values to support the decision processes of NBS planning and implementation for urban area renovation.