An Spatial Statistical Analysis on the Air Quality Change in Multi-Cities System of China with Once Weather Process

Due to the spatial spreading of Air pollution, it is necessary to discuss the air quality from the view of the multi-urban system, rather from the single city. The research on the cross board environ- mental spillover of the air quality among different cities is helpful for controlling the regional air pollution. Data from the China Meteorological Administration reported high values of API in 86 Chinese cities during a cold air process. With the cold air passing, the spatial pattern of the air quality changed. Based on the facts, the spatial auto-correlation analysis is adopted. It showed that before the cold air came, there existed spatial auto-correlation of API among the eighty six cities. Moreover, the degree of correlation was influenced by the geographical distance among the cities, the weaker the correlation, the farther the distance. In other words, the cities closer one another were similar on the pollution behaviors and the condition of pollution spreading. However, when the cold air arrived, which was strong enough to affect all cities in the region, the condition of air pollution spillover changed partly. As a result, the original spatial correlation is still maintained. After the cold air passed, the original situation was destroyed. The pollution materials in those ci- ties, of which are serious in air pollution, spread around. It means that the air quality of urban has the cross board spillover.