Quantification and mapping of the cooling effect of urban parks on the temperate monsoon climate zone

Abstract

As a major type of Nature-based solutions(Nbs)to combat urban climate challenges in densely developed urban areas, urban parks (a combination of blue and green infrastructure) could mitigate regional microclimate by providing a significant cooling effect. In this study, the cooling effects of 50 urban parks in the temperate monsoon climate zone of China were comprehensively evaluated from the maximum perspective and accumulative perspective using four cooling indices, namely, park cooling area (PCA), park cooling efficiency (PCE), park cooling intensity (PCI) and park cooling gradient (PCG). Results have shown that 90 % of urban parks generate significant cooling effects, with land surface temperature (LST) averaging 3.35 °C lower than ambient LST. The park's characteristics significantly influenced the cooling effect (especially PCE, PCI, and PCG). Park size was the main factor contributing to the increase of PCA and the decrease of PCE. Additionally, the threshold value of efficiency for a 130-ha land area was calculated based on PCA. It was difficult to balance the simultaneous growth of cooling range efficiency and accumulative LST reduction efficiency. In the case of limited space, targeting parks with high PCE or PCI and PCG was recommended by designing the complexity of park shapes or increasing the proportion of water bodies. These findings help in the planning and construction of urban parks to rationalize resources to meet the different cooling needs of residents.