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Moreover, harmonizing the increasingly urban development and the ecological balance of urban spaces is becoming one of the biggest challenges for urban planning. Consequently, urban design principles should be driven by ecological ideas of non-linearity and heterogeneity. Ĭlimate and flood-risk adaptation should be flexible and multifunctional because of the uncertainty of climate impacts, especially considering local spatial variability within the urban environment. This situation is likely to become more relevant in the future, particularly in coastal cities where the simultaneous occurrence of pluvial floods and storm surges, combined with high tides, exacerbates the level of risk. Land-use dominated by built-up areas strongly reduces water infiltration and causes excessive runoff. Indeed, these impacts are directly related to microclimate and land-use differences within each city, instead of differing only in their geographical locations and climate conditions. Consequently, the sensitivity of urban areas to runoff is increasing because of the high level of impervious surfaces and the changes in precipitation patterns. An urban (or pluvial) flood refers to the runoff exceedance in respect to the drainage capacity, during high-intensity and short-duration precipitation events. Although climate change effects are directly related to temperature and sea-level rise, the increasing frequency and severity of urban floods are also strictly associated with climate change processes. This work shows the growing interest on further research to develop spatially integrated environmental–economic assessment of NBS implementation, by highlighting the needs and opportunities of a trans-disciplinary approach to support policy-making in the framework of urban climate change adaptation.Ĭlimate change has been widely acknowledged as a global issue that results in even larger impacts on the city level. Most publications provide NBS biophysical impacts assessment, without combining these results with economic evaluation of the flood damages to finally achieve the avoided cost due to the implementation of such solutions. This research review revealed a low-level gap of integration between climate change issues and NBS analysis (i.e., it is commonly used as background condition). Secondly, the NBS approaches were categorized based on the biophysical benefits (in terms of flood-risk reduction) related to each specific solution and the subsequent economic evaluation of such implementations. Firstly, it identifies the biophysical–economic assessment of NBS adaptation measures to reduce urban flood extremes in coastal cities. A systematic review approach has been used to discuss the role of NBS in climate change adaptation. This research aims to provide an overview of NBS impact evaluations by assessing how the scientific literature integrates such economic analysis into urban planning adaptation. There is, however, a lack of comprehensive systematization of economic analysis. A comprehensive mapping of available NBS impact assessment methods could help to accelerate this process. Nevertheless, a wider uptake of such solutions in urban areas faces different challenges and barriers. Over the last decade, the potential of nature-based solutions (NBS) has been recognized to support climate change adaptation, by promoting sustainable urban planning.