Nature-based solutions for improving efficiency in urban settlements. A model for its measurement

The Nature-based solutions (NbS), the concept of which, given the range of objectives included in the approach, has no universal definition (UN, 2020), use the features and complex system processes of nature in order to achieve desired outcomes (EC, 2020). In this framework, maintaining and enhancing natural capital is of crucial importance, as it forms the basis for solutions. Then, the urban green planning is crucial in promoting sustainable urban ecosystems through the mindful use of vegetation. The research is directed at nature-based solutions, considering issues of their effectiveness, through the identification of methods and tools with which to evaluate the effectiveness of nature-based solutions that maximise a range of ecological, social and economic co-benefits. With the aim of measuring the performance of Nbs, the present research proposes a methodological approach to sustainable green urban planning that accounts for the ecological role of vegetation in urban ecosystems. By estimating the functions provided by different green materials (tree, bush, hedge) in urban ecosystems, through a purposely developed set of equations, the methodology makes it possible to optimise the development of urban plans by maximising the contribution of vegetation to ecosystem dynamics. In the end, the model made it possible to measure the performance of the Nbs whose subset is the one we considered, to be understood as a starting point to be able to expand the range and measure the other nature-based solutions.