Spatial And Temporal Heterogeneity Of Air Pollutants And Its Influencing Factors In Downtown Qingdao

Air pollution has affected the lives of urban residents in China.Analyzing the distribution and driving factors of air quality has become the current research hotspot.However,there are few systematic studies on the spatial and temporal heterogeneity of air pollution in Qingdao,and the correlation analysis of weather factors is mostly a linear correlation analysis.In response to these problems,the temporal and spatial heterogeneity of air quality in four districts of Qingdao City was studied,the temporal and spatial heterogeneity of primary pollutants was studied,and the meteorological factors and topographic factors affecting atmospheric pollutants were analyzed.The main research content is as follows:(1)We analyzed the temporal heterogeneity of air quality based on the Kruskal-Wallis rank sum test method,and analyzed the spatial heterogeneity of air quality based on the Wilcoxon signed rank test.The results show that air quality has obvious spatial and temporal heterogeneity.Air quality is the worst in winter and the best in summer.In the entire study area,the pollution in Licang District is the most serious and the pollution in Laoshan District is the lightest.(2)We analyzed spatial distribution of primary pollutants in four seasons based on spatial interpolation techniques,and analyzed the hourly changes characteristics of primary pollutants based on statistical analysis methods.It is found that primary pollutants have obvious spatial and temporal heterogeneity.The primary pollutants are mainly PM10 in spring,PM2.5 in winter,and O3 in summer,and they all have higher concentrations in Liye.The average concentrations of PM10 in spring,O3 in summer,and PM2.5 in winter have certain differences in all four regions.(3)A Copula model was introduced to analyze the linear and nonlinear correlations between pollutants and meteorological factors,terrain factors.The results show that there is a significant positive correlation between PM10,PM2.5 and atmospheric pressure,and there is a significant negative correlation with temperature;there is a significant positive correlation between O3 and temperature,and there is a significant negative correlation with atmospheric pressure.For the first time,using the Copula model,it was found that there was a significant non-linear correlation between pollutants and meteorological factors.There is a significant positive correlation between PM10,PM2.5 and air pressure,and there is a significant negative correlation between PM10,PM2.5 and temperature.There is a significant positive correlation between O3 and temperature,and there is a significant negative correlation between O3 and air pressure.The impact of meteorological factors on pollutants has a certain time lag.There is the greatest correlation between O3 and wind speed,humidity in the previous hour,and there is the greatest correlation between O3 and air pressure of the previous day.PM10 and PM2.5 have the greatest correlation with wind speed in the previous three hours,PM2.5 is most closely related to the temperature of the previous day.Terrain factor also has a certain impact on pollutants.There is a certain negative correlation between PM10 and terrain factor in autumn and winter,and there is a positive correlation between O3 and terrain factor in autumn and winter;PM2.5 has a certain negative correlation with terrain factor in four seasons and presents a linear correlation,and the negative correlation in autumn and winter is greater than that in spring and summer.The distribution of air quality and primary pollutants in Qingdao has obvious spatial and temporal heterogeneity.The pollutants and meteorological factors have obvious nonlinear correlation characteristics,and the meteorological factors have a certain time lag on the impact of pollutants.Terrain factor also has a certain impact on pollutants.