AN EMPIRICAL ANALYSIS OF SPATIAL AND TEMPORAL HETEROGENEITY OF METEOROLOGICAL FACTORS AFFECTING AIR QUALITY IN CHINA

Air pollution is a severe environmental problem in China. Meteorological factors that directly affect the dispersion of air pollutants are closely related to the air quality index(AQI). Extensive literature describes the non-stationarities between meteorological factors and air quality by employing the geographically weighted regression (GWR) or geographically and temporally weighted regression (GTWR). However, most previous studies have ignored the case where the rate of numerical variations has spatial heterogeneity. To better reveal the potential spatiotemporal patterns of the impacts of some selected meteorological factors, such as ground pressure, relative humidity, temperature, wind speed, on air quality in China from 2013 to 2018, we utilized the spatiotemporal weighted regression (STWR) to explore the spatio-temporal non-stationary. Results show that the R-squared (R²) of the STWR model are higher than that of GWR and OLS especially when the rate of change of AQI is fast. Some spatial coefficient surfaces corresponding to different variables show obvious seasonal variations. Their spatial distribution also varies significantly over time. Some interesting findings are as follows: 1) The impacts of humidity on AQI are more obvious in northwestern China from April to June and July to September. 2) Before 2016, humidity had a positive effect on the AQI in most of the northwest, but since then there has been a negative effect. 3) In most southern China areas, the negative correlation between temperature and AQI tends to weaken, which may be caused by the gradual weakening of the temperature inversion phenomenon under climate warming.