The impact of sky view factor on thermal environments in urban parks in a subtropical coastal city of Australia

Sky view factor (SVF), an important geometrical factor for the urban thermal environmental assessment, has a controversial impact in different urban contexts: its value is usually positively correlated with the temperature level in vegetation areas while negatively related to that in built-up areas. This study aims to validate its impacts in vegetation environments, based on the field measurements of 18 urban parks in Gold Coast. A regular grid with 9 points in each park was deployed for the physical measurement of air temperature, air velocity, relative humidity, globe temperature, and SVF. Park sky view factor (PSVF) was proposed to indicate the shading and cooling effect of trees and canopies in parks. Cooling intensity (temperature difference between measured parks and a nearby weather station) and mean radiant temperature (MRT, a thermal comfort index considering objects surrounding the body) were used as the thermal environmental indicators. The study found that PSVF has positive impacts on both park cooling intensity and MRT despite high dense tree may impacts air flow. This research provides evidence and guidance on utilizing urban parks to create thermal comfortable outdoor spaces in subtropical coastal cities.