影响城市热岛的因子分析

THE ANALYSIS OF FACTORS AFFECTING URBAN HEAT ISLAND

影响城市热岛强度的因子随着城市的规模、地理位置和气侯区域变化,也随时间变化。本文利用经验正交函数分解的方法,对上海和南京两城市的同时期观测资料作了分析,发现影响这两个城市热岛强度的物理机制有实质性差异,并从数量上确定各种因子对热岛强度的贡献大小。

In this paper the temporal and spatial variations of intcnsity of urban heat island during the summer of 1959 at the Shanghai and Nanjing are studied by use of the natural orthogonal functions. The population, buildings and industrial heat sources are most important factors which affects the intensity of heat island of the two cities. The influnce of factors is more outstanding in Shanghai than in Nanjing. However, its effect is weaker in daytime and stronger in night in Shanghai, but the opposite in Nanjing. It is caused by the higher and more dense, buildings in Shanghai than in Nanjing. Because of the difference of the geographical positions and topography the factor which affects the heat island arc also different. In the paper the physieal mechanism of each factor has been analysed, so the formation and mechanism of the heat island are explained.