广州典型小区微气候特征观测与数值模拟研究

根据广州下垫面类型和湿热气候特征,选取广州大学城一个小区为试验基地,在典型的晴朗天气条件下,通过实地观测和微尺度数值模式ENVI-met,探讨该地区的微气候特征。数值模式能较好地模拟温度、湿度及流场的空间分布和时间变化特征,结果显示:1模拟区域内不同的下垫面存在高温低湿、低温高湿的现象;2毗邻两栋建筑之间可形成狭管流效应,风速值约为来流风速的1.4~1.7倍;3单体方形建筑物两侧出现角隅大风,阵风风速可达平均风速的2~3倍;4街谷型建筑之间有微弱的街谷涡旋形成,其强度与街谷的几何配置和来流风向有关。

Observational and Numerical Study on the Microclimate over A Typical Community in Guangzhou

Based on the hot and humid climate and the underlying surface of Guangzhou, taking a typical community in Guangzhou Higher Education Mega Center as the test site, we analyze the microclimate characteristics over this area by meteorological observational data and a numerical model ENVI-met under typical sunny weather condition. The results indicate that the ENVI-met model can successfully simulate the special distribution and temporal evolution of temperature, humidity and flow field. ①  There exist high temperature and low humidity, low temperature and high humidity over the different surfaces. ② Channeling effect can be found between the Adjoining Buildings, and the wind speed will become 1.4 to 1.7 times of the upper stream. ③ The corner flow can take place on two sides of the Single Building, and wind gust may be two to three times of the average wind speed. ④ There exists vortex between the Street Canyon Buildings. This effect is connected with the aspect ratio and the approach flow. This study helps us better understand some microclimate phenomenon in the area under sunny weather condition, which may play an important role in pedestrian comfort and diffusion of air pollutants, and can represent the features of hot and humid area. The research has practical significance for the city planning in the region with similar microclimate characteristics.