Spatial patterns of greenspace cool islands and their relationship to cooling effectiveness in the tropical city of Chiang Mai, Thailand.

Urban greenspaces provide evaporative cooling, which can help effectively mitigate the urban heat island (UHI) to achieve a sustainable urban climate. This study examines the cooling effects of greenspace patterns on urban cool islands (UCIs) at the patch level in an urban environment. The effects of 1155 patches of greenspace cool islands (GCIs) on UCIs of the Chiang Mai metropolitan area in Thailand were identified from a satellite image, and the relationships between them were analyzed through correlation and regression analyses. The results indicate that (1) spatial patterns of GCIs have significant effects on their cooling potential, while urban areas with more green patch coverage encounter stronger cooling effects; also, (2) our correlation analysis of three fundamental and widely recognized classes of landscape metrics (area, shape, and core of GCIs with temperature change) shows that the most important metric of effective cooling is the core area. These findings can help planners understand greenspaces established in urban areas and plan urban greenspace to mitigate UHI effects.