Evaluating The Effect of Various Urban Green Infrastructure Types on Thermal Comfort

Abstract

The expansion of cities has led to an increase in man-made surfaces, exacerbating the urban heat island effect. One effective strategy for mitigating urban heat and regulating climate change is the implementation of urban green spaces. This study aimed to compare the cooling potential of various types of urban green infrastructure. The current conditions and different types of green infrastructure were designed and simulated using the ENVI-met model across four scenarios. The results indicated that green walls and green roofs significantly influence the micrometeorological conditions within urban canyons by increasing relative humidity and decreasing air temperature (Ta). Trees, in addition to these effects, also reduce mean radiative temperature (Tmrt) and physiological equivalent temperature (PET). When comparing the cooling potential of different green infrastructure types, the study found that, in terms of thermal comfort, only trees have a substantial impact on reducing PET, with reductions ranging from 6°C to 8.9°C, significantly more than green walls and green roofs, which showed no significant effect. However, in terms of micrometeorological conditions, all three types of urban green infrastructure demonstrated positive effects. Trees exhibited the highest cooling potential, with a reduction of 0.2°C to 1.5°C in air temperature, while green roofs had the lowest impact. The findings of this study provide valuable insights for landscape and urban designers in selecting and designing appropriate urban green infrastructure to enhance micrometeorological conditions and improve thermal comfort.