[Spatio-temporal Characteristics of Air Quality and Influencing Factors in Shandong Province from 2016 to 2020].

ABSTRACT

Based on the daily monitoring data of urban air quality in Shandong province from 2016 to 2020, combined with socio-economic data such as population density and urbanization rate, as well as meteorological data such as wind speed, temperature, and relative humidity, the methods of geographic weighted regression (GWR), multiscale geographically weighted regression (MGWR), and wavelet analysis were comprehensively applied to explore the temporal and spatial distribution characteristics of air pollutants and their relationship with socio-economic and meteorological elements. The results showed that① In the past five years, the air quality in Shandong province has shown an overall improvement trend. Except for ozone, the concentrations of SO2, NO2, PM2.5, and PM10 decreased annually. Additionally, their distribution had obvious spatial differences, which was reflected in the lower concentration of air pollutants in coastal areas. ② PM2.5 in Shandong province had an extremely significant positive correlation with population density and the proportion of secondary industry (P<0.01) but had a very negative correlation with urbanization rate (P<0.01). Moreover, there were scale differences in the spatial relationship. The spatial relationship between population density, civil vehicle volume, industrial power consumption, and PM2.5 was relatively stable, whereas the spatial heterogeneity of the impact of urbanization rate and the proportion of secondary industry on PM2.5 concentration was high. ③ Meteorological factors had different effects on PM2.5 in Heze and Weihai. PM2.5 in Heze had a stronger correlation with air temperature, relative humidity, and sunshine hours, whereas sea land breeze prevailed in Weihai, resulting in a higher correlation between PM2.5 and wind speed. ④ Wavelet analysis showed that the frequency of air pollution in Heze was higher than that in Weihai, approximately one-two weeks/time in winter. In the annual cycle, the PM2.5 in Heze lagged behind the wind speed, whereas the PM2.5 and wind speed in Weihai were in the same phase. To summarize, there were obvious temporal and spatial differences in air quality in Shandong province, which was comprehensively affected by socio-economic and meteorological factors.