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Study on the urban canopy model to evaluate the atmospheric environmental formation technique of the city harmonized with environment.

城市冠层模型评价城市与环境协调的大气环境形成技术研究

基本信息

批准号：
07458122
负责人：
YAMAGUCHI Katsuhito
金额：
$ 4.1万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

The averaged minimum temperature in August at Osaka City is rising about 2 degrees in 100 years. It can be considered that the cause induced heat island phenomenon is the increase of energy consumption and the alteration of the ground surface. In this study, we simulated the influence of the building configration on the wind velocity and potential temperature within the urban canopy layr, using one dimensional atmospheric boundary layr model. It assumed that the building of the same size had been regularly arranged in the shape of a lattice within the urban canopy, and the shortwave radiation and long wave radiation fluxes in the urban canopy were independently estimated correctly by the photon tracking method based on the Monte Carlo method. When a fraction of an area covered with the buildings (eta) increased or the urban canopy height (h_c) became high, it was found that the shortwave radiation flux which the ground surface receives at the daytime decreases, and the long wave radiation flux emitted to the sky decreases at the night time. Next, the heat budget equation model on the building and ground surface, and one dimensional atmospheric boundary layr model were combined, and the temperature and the wind velocity distribution in the urban canopy were predicted. When eta increased or h_c became high, the wind velocity in the urban canopy decreased, and the potential temperature rise at the daytime became small and the potential temperature fall at the night time became also small. It became clear by these results that the increase of eta and the rise of h_c are one of the causes of the heat island phenomenon.

大阪市8月份的平均最低气温100年来上升了2度左右。可以认为，引起热岛现象的原因是能量消耗的增加和地表的变化。本文采用一维大气边界层模型，模拟了建筑构型对城市冠层内风速和势温的影响。假设相同大小的建筑物在城市冠层内按晶格形状有规律地排列，采用基于蒙特卡罗方法的光子跟踪方法独立准确地估计了城市冠层中的短波辐射和长波辐射通量。当建筑物覆盖面积（eta）增大或城市冠层高度（h_c）增大时，地表白天接收到的短波辐射通量减小，夜间向天空发射的长波辐射通量减小。然后，将建筑物和地面的热收支方程模型与一维大气边界层模型相结合，对城市冠层的温度和风速分布进行了预测。当eta增大或h_c增大时，城市冠层内风速减小，白天势温上升变小，夜间势温下降也变小。这些结果清楚地表明，eta的增加和h_c的升高是造成热岛现象的原因之一。