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

大坂市8月的平均最低气温在100年内上升了约2度。可以认为，能源消耗的增加和地表的变化是导致热岛现象的主要原因。本文采用一维大气边界层模式，模拟了建筑物遮挡对城市冠层内风速和位温的影响。假设相同大小的建筑物在城市冠层内呈规则的格子状排列，采用基于蒙特卡罗方法的光子跟踪方法，分别准确地估算了城市冠层内短波辐射通量和长波辐射通量。当建筑物覆盖率（eta）增加或城市冠层高度（hc）增大时，地表白天接收的短波辐射通量减少，夜间发射到天空的长波辐射通量减少。其次，将建筑物和地面的热量收支方程模型与一维大气边界层模型相结合，预测了城市冠层内的温度和风速分布。当eta增大或hc增大时，城市冠层风速减小，白天的位温升高减小，夜间的位温降低减小。结果表明，η的增加和h_c的升高是造成热岛现象的原因之一。

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.