Spatiotemporal heterogeneity of urban air pollution in China based on spatial analysis

This study aims to explore the spatial heterogeneity and temporal dynamics of urban air pollution. The PM10 data from 2004 to 2013 was chosen as the index of air pollutant. Thirty-one major cities including Beijing and its adjacent cities were selected as the study area. Using Global Spatial Autocorrelation, evaluation of whether the air pollutant's pattern is clustered in Chinese mainland area during the study period is conducted. Moreover, the Local Moran's I Index was employed to detect the spatial cluster and outlier distribution of air pollutant. The result shows that air pollution in the study area has made increasing influence on annual average concentration of PM10 in the surrounding area and increasing heterogeneity of PM10. By observing the Local Moran's I Index distribution of PM10 from 2004 to 2013, it is found that several cities around Beijing in north China, which have been suffering from serious air pollution, are spatially aggregated and have influence on their surrounding air quality. In contrast, Haikou and other coastal cities suffer less air pollution and have some purification effects on air environment of surrounding cities. The aggregated distribution pattern is comparatively stable from 2004 to 2013, which led to the speculation that there is interaction on air pollution between the large-scaled aggregated regions and individual cities. This paper is significant to inspire the awareness of air pollution by local government and the public.