Clustering evolution characteristics and synergistic factors of air pollution in Beijing-Tianjin-Hebei and surrounding areas from the perspective of dynamic space.

Based on spatial correlation analysis and the dynamic spatial autoregressive model, this paper took AQI and six types of pollutants, including PM2.5, PM10,SO2, etc., as the research objects to explore the time-space agglomeration evolution characteristics and related synergistic factors of air pollution in '2 +26 +3' cities of Beijing-Tianjin-Hebei and surrounding areas from 2013 to 2018. This study found that: (1) Air pollution presented a complex evolutionary trend. AQI, PM2.5 and PM10 were mainly presented as local agglomeration of high-high type, while SO2, CO and O3 having agglomeration of both high-high type and low-low type; PM2.5, PM10 and SO2 had a high degree of global correlation, while CO and O3 were relatively weak; the local and global correlation of NO2 were not significant. (2) The 'space-time scale effect' of air pollution was very significant. As far as this region was concerned, economic and social development factors mainly had a positive impact, while impact of ecological protection factors were mainly negative, and the previous contribution was significantly higher than that of the latter. Comprehensive improvement of the air quality in Beijing-Tianjin-Hebei and surrounding areas can be promoted from four aspects: The first is to coordinate the 'unity of opposites' relationship between appeals for local development and objectives of regional collaborative governance, and to establish and improve the accounting and transfer payment (compensation) mechanism of interest difference in the region. The second is to coordinate the overall and local 'common but differentiated' joint defense and joint control mechanisms, to build a multi-center, compound joint governance system, and to guide refined governance with special responsibility goals. The third is to promote the construction of a regional 'three-dimensional integration' collaborative system, and to solve the 'greatest common divisor' of various regions to reach a solid cooperative alliance from the aspects of main functional zoning and clean capacity replacement. The fourth is to improve the reform of local government performance and promotion system, and to strengthen its internal motivation and sense of responsibility to be integrated into the regional coordination system by expanding the dimensions of environmental governance assessment and reducing the weight of economic indicators. [ABSTRACT FROM AUTHOR]