Objective To study the spatial features of annual mean concentrations of inhalable particles (PM10), sulfur dioxide (SO2), and nitrogen dioxide (NO2) in 110 major cities in China between 2004 and 2008.
Methods The spatial heterogeneities of annual mean concentration distributions of air pollutants were analyzed using the global and local spatial autocorrelation methods, which was based on spatial weight matrix.
Results From 2004 to 2008, in the 110 major cities in China, there were significant positive spatial autocorrelations in annual mean concentrations of PM10 & SO2 and of NO2 except for a random distribution presented in 2008. The hot spots of annual mean concentrations of PM10 distributed over the central-north regions of Henan Province, north regions of Shanxi Province, and central regions of Gansu Province; SO2 over the north-east regions of Shanxi Province and the central regions of Guizhou Province; and NO2 over the urban agglomerations of the Pearl River Delta, the Yangtze River Delta, and Beijing-Tianjin region, respectively.
Conclusion PM10, SO2, and NO2 present area clustering in China.
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