Study on Spatio-Temporal Evolution Law and Driving Mechanism of PM2.5 Concentration in Changsha–Zhuzhou–Xiangtan Urban Agglomeration

Abstract

Since the 21st century, China has made many explorations to alleviate the increasingly serious air pollution problem. This study analyses the spatio-temporal evolution characteristics and future development of PM2.5 concentration in the Changsha–Zhuzhou–Xiangtan urban agglomeration from 2008 to 2019. In addition, the driving mechanism of spatial differentiation of PM2.5 concentration in this urban agglomeration was also investigated. The results were as follows. Firstly, the PM2.5 concentration showed a trend of gradual decline between 2008 and 2019. Secondly, the PM2.5 concentration distribution was high in the northwest and low in the southeast. Thirdly, PM2.5 concentration showed a strong spatial agglomeration. Fourth, except for some rural areas of Chaling County and Yanling County, the concentration of PM2.5 in other areas was very likely to continue the past trend of gradual decline. Finally, natural and meteorological conditions played a leading role in the evolution of PM2.5 concentration. The influence of socioeconomic factors is small now, but the trend is increasing. To improve air quality deeply, policymakers need to promote comprehensive control of regional air pollution by simultaneously reducing emissions and taking comprehensive treatment. They also need to strengthen supervision to prevent excessive pollution in some rural areas from worsening air quality in the surrounding areas.