Heterogeneity Impacts of Natural and Socioeconomic Factors and Their Interactions On PM2.5 in the Yangtze River Economic Belt

Haze has reached epidemic levels in many cities of China in recent years. Only limited studies have explored the impacts of driving factors and their interactions on the spatiotemporal heterogeneity of PM 2.5 . This paper investigates the spatiotemporal characteristics of PM 2.5 pollution through spatial analytical methods based on retrievals of satellite aerosol optical depth (AOD) data from the Yangtze River Economic Belt (YREB) between 2000 and 2017. Geographically weighted regression (GWR) and geodetector models were applied to assess the directions and strength of association between natural and socioeconomic conditions and PM 2.5 pollution. The results indicate that the annual concentration range of PM 2.5 in the YREB was 23.49–37.37 μg/m 3 with an initial increasing and later declining trend. The PM 2.5 pollution displays a diagonal spatial distribution pattern of high in northeast and low in southwest and a noticeable spatial convergence. The spatial variability of PM 2.5 pollution was enlarged and its main fractal dimension was in the northeast–southwest direction. There were clear spatiotemporal variations in the impact of natural and anthropogenic factors on PM 2.5 pollution. Interactive factors included bi-factor and nonlinear enhancements. Our findings contribute to a better understanding of the impact mechanisms of PM 2.5 pollution and the geographical factors in forming persistent and highly polluted areas and imply that more specific coping strategies need to be targeted in various areas toward successful particulate pollution prevention and control.