Contextual Conditions for the Application of Urban Heat Mitigation Measures: A Review of Reviews

Climate change and urban heat islands are contributing to the warming of urban areas worldwide. Previous research has made it clear that the implementation and success of urban heat mitigation measures are dependent on context, but which contextual conditions matter is less clear. This study addresses the state of knowledge regarding contextual conditions for the application of physical urban heat mitigation measures, and gauges the transferability of measures to Nordic cities. A scoping review of literature reviews was done. Results show that contextual conditions are not systematically reported in literature, and are often mentioned implicitly rather than explicitly. Relevant contextual conditions for physical mitigation measures include: climate and prominent wind patterns; water availability; soil perviousness; the population´s thermal comfort and tolerance; site geometry; surrounding surfaces; space availability and site adaptability; budget; maintenance; information availability; proximity to the sea; site function; and sun path; risks or co-occurring societal challenges; social norms, cultural values and aesthetics. Contextual conditions for which commonalities were found between Nordic cities allowed for the creation of an overview of considerations for transferability of measures to this region, which should inform design criteria for future planning. Knowing what contextual conditions are relevant to heat mitigation measures can guide the analysis of transferability of measures in the future, and clusters of cities with similar contexts can be made, between which the transferability of solutions would be high.

Keywords: Heat mitigation, Urban climate, Thermal comfort, Urban heat island, Climate Change adaptation, Transferability of solutions.