Hindering the impact of building characteristics on greenbelt cooling effects: A perspective of quantitative simulation with in situ measurements.

The urban environment, linked with human health, is a complex system disturbed by the roughness of the urban surface, unusually marked by buildings and greenbelts. The cooling effect of greenbelts inevitably responds to the distance from their locations to buildings and their characteristics, while the buildings are hardly independent of the greenbelts in terms of heat effects. To determine the role of building and greenbelt characteristics in mitigating heat stress, our study selected 3 greenbelts and 6 buildings in Beijing, China, and classified them into 2 clusters to compare the difference in monitored outdoor air temperatures (ATs) within two different building characteristics - height and length. One-way analysis of variance (ANOVA) and the least significant difference (LSD) were then employed to further test for significant difference. Our study indicates that each of the two characteristics (height and length) can bring about a significant hindering impact on greenbelt cooling effects. A greater building height or length has a greater hindering force to air (heat) flow. Knowing one or more of the characteristics of greenbelts or buildings is very critical to the improvement of the urban heat environment. Our study proposes an effective and practical outcome for facilitating governmental policy-making and planners' actions.