城市中心区空间形态与风热环境的关联性——以沈阳市为例

The Correlation between Spatial Morphology and Wind-Thermal Environment in Central Urban District——A Case of Shenyang

城市中心区建设强度高且人口密集,其热环境问题更为显著。为研究城市形态对风热环境的影响,本文基于ENVI-met对沈阳太原街商业区夏季风热环境的模拟结果,分析了空气温度、地表温度及平均风速的相互关系,并定量研究了10个城市形态指标对三者的影响。结果表明,夏季空气温度与风速呈正相关,地表温度与风速呈负相关,但空气温度与地表温度间没有明显关联。建筑密度、平均建筑体积与空气温度呈正相关,与地表温度呈负相关。天空开阔度与空气温度呈负相关,与地表温度呈正相关。围合度是影响风速的主要指标,降低围合度可提高风速,但增加了夏季热气流对地块温度的影响。研究结果可为城市设计过程中综合改善风热环境提供有效依据。

The central urban districts are intensely developed and crowed with people,which causes remarkable problem of the thermal environment.This study aims to investigate the effect of urban morphology on the wind-thermal environment.The mutual effects of air temperature(AT),ground surface temperature(ST)and average wind speed(WS)were analyzed,and their quantitative relationships with 10 morphological indicators were investigated based on the simulation of ENVI-met model.The results indicate that the AT is positively related to WS in summer,while the ST is negatively related to WS,and the AT is not significantly related to ST.The building footprint ratio(BFR)and mean building volume(MV)have positive correlation with AT,and have negative correlation with ST.The sky view factor(SVF)has negative correlation with AT,and positive correlation with ST.The enclosure degree(ED)is the most influential indicator for WS.Decrease of ED is beneficial for improving WS,but also intensifies the effect of thermal current on the plot-temperature in summertime.The results provide efficient basis for improving the wind-thermal environment in the processing of urban design.