The impact of green space structure on physiological equivalent temperature index in open space

Planting vegetation in urban areas can tilt the heat balance in favor of cooler temperatures. For this reason, studying the extension and intensity of the cooling effect of vegetation and the factors which can influence these two parameters is significant in open space design. In this regard, the purpose of the present study was to analyze the different thermal behaviors of green spaces at the micro scale and explain the reason of different extensions and intensities of the cooling effect in spaces which have vegetation. The region of Sistan (Zabol), situated east of Iran, was selected as the study area. Data analysis and study of the parameters affecting physiological equivalent temperature index indicated that the highest impact of green space on this index is related to air temperature and mean radiant temperature among all microclimatic parameters. It was revealed that in stations with vegetation, mean air temperature was lower by 1 °C, mean radiant temperature was lower by 6 °C and PET index was lower by 7 °C in comparison to stations without any vegetation. Analysis of the relation between PET and spatial variables which form the structure of green space, indicated that flooring type has a significant relation with physiological equivalent temperature.