Effects of internal and external planning factors on park cooling intensity: Field measurement of urban parks in gold coast, Australia

Abstract

Urban parks can help to ameliorate the urban heat island effect. This study measured thermal environments in 18 urban parks in Gold Coast, a coastal subtropical city. In particular, this study categorized and investigated two types of planning factors that may affect the thermal environment in parks: internal factors, including park tree coverage and sky view factor, and external factors, such as distance to the sea. Through physical measurement and analysis of variance, it is found that that the park cooling intensity was affected by both internal and external factors, while their effects varied in different periods of the day. The effect of trees was most significant in the evening. An increase of park tree coverage and a decrease of sky view factor could reduce evening air temperature by around 2 °C and 2.5 °C respectively. The effect of the sea was more significant in the morning. The park with the shortest distance to the sea could decrease air temperature by more than 2 °C in the morning. This study identified the features of thermal environment in coastal subtropical areas and their influential factors; it also provided evidence and guidance for urban planning and design to improve urban thermal environment.