Research On The Spatiotemporal Distribution Characteristics And Influencing Factors Of Ozone Pollution In China

In recent years,the air pollution caused by the acceleration of urbanization and industrialization has attracted wide attention from all walks of life.China has made many efforts to achieve continuous improvement of air quality and achieved certain results.As represented by PM2.5,the annual average concentration of pollutants continues to decline,but at the same time,the problem of ozone pollution has gradually emerged,which has brought new challenges to the comprehensive control of air pollution in China.Existing research on ozone pollution mainly focuses on its causes,negative effects,spatiotemporal distribution,and influencing factors.However,the research on the spatiotemporal distribution of ozone pollution still has some defects such as small sample data or limited observation scope.In addition,environmental pollution issues are inseparable from economic and social development,but few studies have analyzed the potential socio-economic factors behind ozone pollution in Chinese cities.To obtain a deeper understanding of the current status of ozone pollution and the association between ozone pollution and social and economic development in China,this dissertation investigated the spatiotemporal distribution characteristics and socio-economic influencing factors of ozone pollution based on the ozone concentration data of 338 cities from January 1,2016,to February 28,2019,and urban socio-economic indicators data of2017.Initially,from the spatial dimension,China is divided into seven geographic regions and four major urban agglomerations.The spatial distribution characteristics of ozone pollution in China have been analyzed in detail from whole to parts.Then,from the temporal dimension,the time granularity is divided into six levels,and the temporal variation characteristics of ozone concentration in China have been investigated.Finally,through the association rule mining algorithm,the potential socio-economic influencing factors of urban ozone pollution have been explored from annual,seasonal,and weekly perspectives.The main findings are summarized as follows:(1)From the spatial dimension,the region with the most severe ozone pollution in China is North China,especially the Beijing-Tianjin-Hebei urban agglomeration.Ozone pollution has shown regional and concentrated distribution characteristics in some regions,and the tendency presents expanding outward from the center.The core cities in different geographic regions and urban agglomerations tend to have a higher level of ozone concentration.(2)From the temporal dimension,ozone pollution increased significantly from 2016 to 2017.In most regions,the ozone concentration is the highest in summer and the lowest in winter.The center of ozone pollution shifts from northern China to southern China from spring and summer to autumn and winter.The monthly variation of ozone concentration is roughly in an inverted “V”shaped characteristic.There is no direct evidence of the Ozone Weekend Effect has been verified in weekly variation in this research.As for the diurnal variation,the ozone concentration reaches the valley value in the early morning,and rises to its peak in the afternoon.(3)The association between urbanization and industrialization and ozone pollution is confirmed from three different perspectives: annual variation,seasonal variation,and weekly variation.The category of “Industrial production and pollution”,especially indicators related to power supply,seems to be one of the most important influencing factors of urban ozone pollution.Moreover,human behavior and activities are the key influencing factors of the weekly ozone concentration variation.Based on the above research findings,combined with the spatiotemporal distribution characteristics of ozone pollution in China and the socio-economic characteristics of different cities,policy recommendations for controlling the urban ozone pollution in China have been put forward from the technical,national,corporate,municipal,and personal perspectives.