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

城市冠层和乡村地表的基本热力学特征由反照率、斯坦顿数和由 c ρ λ 定义的热惯性值决定，其中：c 是有效热容，ρ 是有效密度，λ 是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 年）。 Sha开发的宫城县包括仙台市的海风模拟模型，最底层的网格距离为1km。模拟结果显示，风和气温的总体规律与观测结果和实际情况基本一致。城市中心区的气温，但没有看到城市绿化带的影响，这意味着网格距离应该小于100m，甚至小于1m。采用非常小的网格垂直集成的二维模型，阐明了绿化带的效应，绿化带中叶片气孔的蒸发蒸腾作用对叶片温度的冷却是最有效的防热效果。在相同的树林总数和相同的树林叶面积指数的条件下，即使在二维空间中，布置大量的小绿带也比布置少量的大绿带更有效。建模尤其是在散布小绿带的情况下，通过观测数据和理论研究，研究了表面边界层湍流的特征。对于空气的原始方程（Ishida 和 Yasuda，2005），压力项已被证明在湍流能量方程中非常重要，我们现在将继续发展湍流。扩散率较小