Temporal and spatial variation characteristics of air pollution and their influencing factors in Northwest China

In order to explore the regional environmental air quality in Northwest China, statistical analysis, Kriging interpolation, spatial autocorrelation, and geographic weighted regression models were used to analyze the 161 monitoring stations in Northwest China from 2015 to 2018. The analysis of real-time air quality monitoring data revealed the characteristics and influencing factors of air pollution in Northwest China during the four years. The results showed that: ① From 2015 to 2018, the overall air quality of the five northwestern Provinces (regions) has gradually improved. Among them, the number of cities with excessive pollution in 2017 was the largest, Gansu Province had the largest number of lightly polluted days, and Xinjiang had the largest number of severely and severely polluted days. ② The areas with high AQI pollution values from 2015 to 2018 were all in Xinjiang, and the six high-value areas of pollutant concentration were different. ③ Geographically weighted regression model showed that natural and socioeconomic factors had a significant impact on the distribution of AQI, but in different places there were different influencing factors among which wind speed, temperature, relative humidity, green coverage, proportion of secondary industry, total population, and other natural and socioeconomic factors had the most significant impact on the AQI index in Northwest China.