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

城市冠层和农村地表的基本热力学特性由反照率、斯坦顿数和由c ρ λ定义的加热惯性值确定，其中c为有效热容，ρ为有效密度，λ为冠层的有效热导率。这些值由建筑物的高度、数量密度和总覆盖率确定（Hizuka and Yasuda, 2005）。利用这些数值和沙所建立的非水动力模拟模型，研究了仙台市宫城县上空的海风。最底层网格距离为1km。在模拟结果中，一般的风型和气温与观测结果和城市中心地区的气温基本一致。但是城市绿化带的效果却没有被看到。这个结果意味着网格距离应该小于100米或者小于1米。因此，我们采用了更小网格垂直集成的二维模型，明确了绿化带的作用。绿化带中叶片气孔蒸腾作用对叶片温度的降低是对抗热岛最有效的方法。在林木总数相同、林木叶面积指数相同的条件下，多片小绿化带的布置比少片大绿化带的布置效果更好。即使在二维模型中，涡旋扩散率的表示也是最重要的。特别是在小绿化带分散的情况下，扩散率的表现是非常重要的。通过对观测数据的分析和对空气原始方程的理论研究（Ishida and Yasuda, 2005），对地表边界层湍流特性进行了研究。在紊流能量方程中，压力项是非常重要的。现在我们将继续发展湍流扩散。少

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