The spread of atmospheric pollutants in the Sichuan Basin is difficult because of its unique topography, static wind, high humidity, and other meteorological conditions. Owing to the acceleration of urbanization and industrialization, PM2.5 pollution in the region is becoming increasingly severe, and the Sichuan Basin has become one of the key areas of national air pollution prevention and control. In this study, based on the remote sensing inversion product of PM2.5 concentration, spatial autocorrelation and gray correlation analyses are used to evaluate the spatial and temporal distribution characteristics and influencing factors of PM2.5 concentration in the Sichuan Basin. The results show that PM2.5 concentration has significant spatial aggregation; the high-high aggregation types are concentrated, low-low aggregation types are more dispersed, and coniferous forest has a significantly higher inhibitory effect on the absorption of PM2.5 than the shrub, grassland, and other vegetation types. The main meteorological factors affecting PM2.5 concentration in the Sichuan Basin are wind speed and temperature; population density and economic scale are the main human-activity factors affecting PM2.5 concentration in the Sichuan Basin, and the change in the industrial structure and scale also has a certain influence on the PM2.5 concentration.
Keywords: Sichuan Basin; fine particulate matter (PM2.5); gray correlation analysis; spatial aggregation; spatial and temporal pattern.