给出了一种从建筑学场地设计的角度出发,对建筑外部空间形态特征——围合度与场地微气候的关联性进行研究.建筑外部空间形态是建筑师可以操作的对建成环境的调控手段,场地微气候是环境调控的主要目标和媒介,建筑低碳节能是环境调控要达成的目的.在对上海市内城区典型办公建筑群案例——国歌广场的研究中,采用现场微气候实测的方法,分析外部空间形态与场地微气候的温度场、风场、日照分布的关系.经场地平面、剖面类型分析探讨场地外部空间形态特征与场地微气候特征的关联性.场地实测的数据表明外部空间几何形态对场地微气候指标如温度、风速、太阳辐射有显著影响.对实测数据的相关性分析和回归分析显示场地微气候与场地围合度因素显著相关,包括建筑、地形和绿化的围合,围合度的量化变量指标包括剖面高宽比(H/W)、平面通透率(L/C)、天穹可见度(SVF)、地面升起与下沉的高差(H).实测数据分析表明场地中的空气温度(TMP)与天穹可见度(SVF)正相关,夏季三次曲线模型拟合度较好,冬季相关性比夏季弱;场地中的风速(WNS),夏季与平面通透率(L/G)正相关,相关性较弱,冬季与剖面高宽比(H/W)负相关,相关性比夏季显著;场地中的太阳辐射强度(SRD)与天穹可见度(SVF)正相关,夏季为三次曲线模型拟合度较好,夏季相关性比冬季显著.天穹可见度(SVF)与平面通透率(L/C)、剖面高宽比(H/W)可以作为影响太阳辐射和热压通风作用的指标.总结得出了夏季和冬季场地空间形态围合度要素与场地微气候要素关系的拟合模型.对场地热环境的太阳辐射、温度场、风场的分析发现,由半围合、半覆盖的空间形式组合的多样化的空间形态最有利于场地中微气候的调节.
This paper studies the outdoor space form parameter, the correlation between degree of enclosure and urban microclimate, from the perspective of architecture site design. Outdoor space form is one of the control factors that can be used in the built environment adjustment by architects. Urban microclimate is the media and one of the main targets of the built environment regulation. Low carbon emission and energy saving is the goal of environmental regulation. Taking the typical office buildings site in the national anthem square in Shanghai as a case study, field microclimate measuring approach was employed to analyze the correlation between outdoor space form and temperature, wind and sunlight of site microclimate. By analysis of site plan and section, the paper discusses the correlation between outdoor space form and microclimate. The result of the analysis indicates that the temperature, wind speed and solar radiation were significantly influenced by outdoor space geometry. A simple scatter plot and linear fit analysis indicates that the site microclimate is significantly correlated with the "degree of enclosure" contributed by buildings terrain and trees, quantified by the aspect ratio (H/W), plan transparent rate (L/C), Sky view factor (SVF) and Elevation difference (H). It suggests that, within the practical range, increasing SVF could increase air temperature (TMP) and solar radiation (SRD); increasing plan transparent rate (L/C) and aspect ratio (H/W) could decrease wind speed (WNS). Under the measured site environment, SVF cooperated with L/C and aspect ratio (H/W) could indicate the thermal buoyancy driven airflow rate that is determined by solar radiation heating. Summer and winter mathematical model was summarized through multiple regression analysis of outdoor space degree of enclosure parameter and microclimate element. A discussion on thermal environment of the measured site suggests an outdoor space form design approach that goes for diverse space form w