Regional characteristics and spatial correlation of haze pollution: Interpretative system analysis in cities of Fenwei Plain in China

Urban agglomeration is an important model for promoting global economic development and has made important contributions to global economic integration. However, as the core area of urbanization and industrialization, urban agglomerations also contribute to air pollutant emissions primarily due to the agglomeration of population and industry. The mutual influence of air pollution between different cities in urban agglomerations has brought significant challenges to global environmental governance. The Fenwei Plain is one of the most severely polluted areas in China. We collected daily average PM2.5 concentration data of 11 cities in the Fenwei Plain, China in 2019. We then developed an interpretive structural model to statistically analyze the spatial correlation and hierarchical transmission of haze pollution between the 11 cities. The results showed that haze pollution has a strong systematic correlation between the 11 cities, and a regional haze pollution community has formed throughout the region. Haze pollution also exhibits evident transmission and spatial correlations between the cities. The transmission starts from Baoji and ends at Sanmenxia, with mutual interactions between the cities of Xi'an, Xianyang, Weinan, Tongchuan, Jinzhong, Lvliang, Linfen, Yuncheng, and Luoyang. Thus, air pollution prevention and control in the Fenwei Plain should consider the spatial correlation of haze pollution between different cities, especially in autumn and winter, and should rationally be implemented in key urban cluster areas. We recommend building a coordinated governance between cities to improve the overall air quality. Our findings shed a light for coordinated pollution management in urban agglomerations worldwide.