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Heat Island due to the Increasing of Height and Number-density of Buildings in the Big City, and the Relaxation Effect of Green

大城市建筑高度和数量密度增加造成的热岛效应及绿化的缓和作用

基本信息

批准号：
15310003
负责人：
YASUDA Nobuhisa
金额：
$ 7.55万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

The fundamental thermodynamic characteristics over the urban canopy and the rural surface are determined from the albedo, the Stanton number and the value of heating inertia defined by c ρ λ where : c is the effective heat capacity, ρ is the effective density and λ is the effective heat conductivity of the canopy layer. These values are determined from the height, number density and the gross coverage ratio of the buildings (Hizuka and Yasuda, 2005). With these values and the non-hydrodynamic simulation model developed by Sha, the sea-breeze over the Miyagi Prefecture including Sendai City. The distance of mesh in the lowest layer was 1km. In the results of simulations, general patterns of wind and air temperature nearly coincide with the observation results and the air temperature in the central area of the urban. But the effects of the green belts in the urban were not seen. This result means that the mesh-distance should be smaller than 100m or maybe smaller than 1m. Therefore, the … More 2-dimensional model vertically integrated were used with the very small mesh and the effect of green belt were clarified. The cooling of the leaf-temperature due to the evapo-transpiration from the stomata of leaves in the green belts is most effective against the heat islands. Under the conditions with the same total number of woods and the same leaf area index of woods, the arrangement of the many small green belts is more effective than the arrangement of the few number of large green belts. Even in the 2-dimensional model the representation of eddy diffusivity is most important. Especially in the cases with the scattered small green belts, the presentations of diffusivity were showed to be very important. The characteristics of turbulence in the surface boundary layer were investigated with the analyses of observation data and theoretical investigations for the primitive equations of air(Ishida and Yasuda, 2005). The pressure terms have been showed to be very important in the turbulent energy equations. We will now continue the development of turbulent diffusivity. Less

本文根据林冠层的有效热容量、有效密度和有效导热系数c ρ λ确定了城市林冠层和农村地表的基本热力学特征。这些值是根据建筑物的高度、数量密度和总覆盖率确定的（Hizuka和Yasuda，2005）。利用这些值和沙开发的非水动力模拟模型，计算了包括仙台市在内的宫城县上空的海风。最低层网格间距为1km。在模拟结果中，风场和气温场的一般分布与观测结果和城市中心区的气温场基本吻合。但城市中的绿色带的作用并没有显现出来。这一结果意味着网格间距应小于100 m或可能小于1 m。因此 ...更多信息 2-三维模型采用垂直积分的方法，网格很小，明确了绿色带的作用。绿色带叶片气孔蒸散对叶温的冷却作用对缓解热岛效应最为有效。在林木总株数和林木叶面积指数相同的条件下，多条小绿色带的配置比少条大绿色带的配置效果更好。即使在二维模型中，涡扩散系数的表示也是最重要的。特别是在小绿色带分散的情况下，扩散系数的呈现被证明是非常重要的。通过对观测数据的分析和对原始空气方程的理论研究（Ishida and Yasuda，2005），研究了地面边界层中的湍流特性。压力项在湍流能量方程中是非常重要的。我们现在将继续发展湍流扩散率。少