建筑动力学作用对近地面短历时点源污染扩散的影响  

Influence of Dynamical Effect of Urban Buildings on Diffusion Process of Pollutants Released from Short-Duration Point Source near Ground

作　　者：李磊[1] 李书严[1] 轩春怡[1] 郭文利[1] 黄顺祥[2] 刘峰[2] 

机构地区：[1]北京市气象局北京市气候中心,北京100089 [2]防化指挥工程学院,北京102205

出　　处：《城市环境与城市生态》2008年第5期32-36,共5页Urban Environment & Urban Ecology

基　　金：国家自然科学基金(40652001;40775015);北京市财政局项目"污染扩散数值模式开发";国家十一五科技支撑计划项目(2006BAK01A14)

摘　　要：利用一次示踪剂扩散外场实验获得的数据,对城市小区尺度模式USSM在模拟短历时点源方面的能力进行了验证,结果表明USSM能较为合理地描述城区短历时点源的扩散特征。利用USSM进行了3个案例的情景模拟分析,得出结论:1)街区内建筑群的平均高度越高,建筑群之间的流场越紊乱,并且越容易形成涡旋型环流,同时建筑群之间的风速会变得越来越小。除此之外,随着建筑群平均高度的增加,受建筑群影响风场出现扰动现象的范围越大。2)建筑群平均高度的增高会显著降低街区内的扩散能力,并且这种影响可能是非线性的,当街区由小高层建筑为主变为高层建筑为主时,污染物输送扩散效率会急剧下降。By using an observation data collected from a smog tracer diffusion experinment,it was validated that a micro-scale model,namely Urban Sub-domain Scale Model(USSM),can simulate a short duration point source.The comparison between the observed and simulated data showed that USSM could reasonably describe the diffusion process of the pollutant released from a short-duration point source in urban streets.Three numerical tests were performed by using USSM,and some conclusions were drawn from these tests: 1) Along with the increase of the average building height,the flow field among the structures becomes more disturbed and the average wind speed among the structures became lower,and at the same time,the area with an obviously disturbed wind field enlarged.2) As the average height of structures increased,the diffusion ability of the city-block decreased in a possible nonlinear way.When the average height of the structures in the city-block was changed from 18m to 36m,the diffusion ability of the city-block drastically decreased.

关 键 词：城市建筑群 污染物 扩散 数值模拟 

分 类 号：X51[环境科学与工程—环境工程]