A preliminary study on the local cool-island intensity of Taipei city parks

That green-spaces relieve urban heat is well known in urban landscape planning. Scientific information on what kinds of green-spaces best reduce heat, however, is still largely unknown. This is a preliminary study aimed at (1) devising a method to detect and compare the local cool-island intensities of various urban parks; (2) verifying that this local cool-island intensity differs among parks; (3) determining whether this local cool-island intensity is related to park characteristics. Results from air–temperature measurements in and around 61 Taipei city parks showed that urban parks were on average cooler than their surroundings, confirming the term “urban cool-islands.” However, approximately one-fifth of the parks were warmer than their urban surroundings. At noon in summer, parks with ≥50% paved coverage and little tree- and shrub-cover were on average warmer than their surroundings. Large parks were on average cooler than the smaller ones, but this relationship was non-linear. In Taipei, parks differed in their local cool-island intensity and this intensity can be related to park characteristics. Before further details concerning better planning and design approaches to mitigate urban heat-islands can be addressed, a neighborhood-scaled understanding of the urban microclimate is first needed as a basis.