Celebrating the 2-Year-Birthday of Science Bulletin

Heterogeneity and the determinants of PM2.5 in the Yangtze River Economic Belt

Haze has reached epidemic levels in many Chinese cities in recent years. Few studies have explored the determinants and heterogeneity of PM2.5. This paper investigates the spatiotemporal characteristics of PM2.5 through spatial analytical methods based on aerosol optical depth data from the Yangtze River Economic Belt (YREB) between 2000 and 2017. Geographically weighted regression and geodetector models were applied to assess the heterogeneity of key factors influencing PM2.5. The results indicate that the annual concentrations of PM2.5 in the YREB were 23.49-37.37 μg/m3, with an initial increase and a later decrease. PM2.5 pollution showed a diagonal high spatial distribution pattern in the northeast and a low spatial distribution in the southwest, as well as a noticeable spatial convergence. The spatial variability of PM2.5 was enlarged, and its main fractal dimension was in the northeast-southwest direction. There were clear spatiotemporal variations in the impacts of natural and anthropogenic factors on PM2.5. Our findings contribute to a better understanding of the impact mechanisms of PM2.5 and the geographic factors that form persistent and highly polluted areas and imply that more specific coping strategies need to be implemented in various areas toward successful particulate pollution prevention and control.

Spatiotemporal dynamics and impacts of socioeconomic and natural conditions on PM2.5 in the Yangtze River Economic Belt

The determination of the spatiotemporal patterns and driving factors of PM_2.5 is of great interest to the atmospheric and climate science community, who aim to understand and better control the atmospheric linkage indicators. However, most previous studies have been conducted on pollution-sensitive cities, and there is a lack of large-scale and long-term systematic analyses. In this study, we investigated the spatiotemporal evolution of PM_2.5 and its influencing factors by using an exploratory spatiotemporal data analysis (ESTDA) technique and spatial econometric model based on remote sensing imagery inversion data of the Yangtze River Economic Belt (YREB), China, between 2000 and 2016. The results showed that 1) the annual value of PM_2.5 was in the range of 23.49-37.67 μg/m³ with an inverted U-shaped change trend, and the PM_2.5 distribution presented distinct spatial heterogeneity; 2) there was a strong local spatial dependence and dynamic PM_2.5 growth process, and the spatial agglomeration of PM_2.5 exhibited higher path-dependence and spatial locking characteristics; and 3) the endogenous interaction effect of PM_2.5 was significant, where each 1% increase in the neighbouring PM_2.5 levels caused the local PM_2.5 to increase by at least 0.4%. Natural and anthropogenic factors directly and indirectly influenced the PM_2.5 levels. Our results provide spatial decision references for coordinated trans-regional air pollution governance as well as support for further studies which can inform sustainable development strategies in the YREB.