Spatio-temporal characteristics and coupling coordination relationship between urbanization and atmospheric particulate pollutants in the Bohai Rim in China

The coordinated development of urbanization and atmospheric environment is of great significance for improving the quality of urbanization and solving air pollution problems in the Bohai Rim region. We have constructed urbanization quality level system indicator system and atmospheric environment system indicator system. By combining the coupling coordination degree model and spatial autocorrelation method, we analyze the spatiotemporal changes of urbanization, PM2.5, and PM10 of 43 cities in the Bohai Rim region from 2015 to 2020 using the coupling coordination model and spatial autocorrelation method, revealing the spatiotemporal evolution law of the coupling coordination relationship between regional urbanization system and atmospheric environment system. The results show that: (1) The overall urbanization level is increasing and the concentration of atmospheric particulate matter pollution is decreasing from 2015 to 2020 in the Bohai Rim; the urbanization level shows a spatial distribution pattern of high in the northeast and low in the southwest, and the concen-trations of PM2.5 and PM10 show a pattern of high in the southwest and low in the northeast, with obvious clustering characteristics; (2) The coupling and coordination relationship between urbanization and atmospheric environment is showing an increasing trend in the Bohai Rim region. During the research period, the lowest, highest, average, and coupling coordination levels of the coupling and coordination scheduling are continuously increasing. The spatial distribution pattern of the coupling coordination degree is low in the southwest and high in the northeast, and there is a strong regional convergence of the coupling coordination type transformation, with certain spatial and temporal dependence.