Spatial Correlation And Influencing Factors Of Air Quality In The Middle Reaches Of Yangtze River

Air pollution has always been a concern of the whole society.The quality of air has a direct impact on People’s Daily life and the development of social economy.For the agglomeration of air pollution between cities and the widespread existence of pollution spillover effect,it is necessary to study the linkage of air quality between cities.It is particularly important to control air agglomeration pollution in urban areas,effectively improve air quality,study the influence direction and degree of main influencing factors related to air quality,and promote the development of regional greening.Based on domestic and foreign literatures,the present situation of air quality in the middle reaches of the Yangtze River was visualized based on the air quality index and various influencing factors of 28 cities in the middle reaches of the Yangtze River from 2015 to 2019.The scope of the study forms a gradual exploration process from the whole to the individual and then to the local area,to find out the cities with core influence in the research area and analyze the agglomeration effect of cities,which provides a scientific basis for the joint prevention and control of air quality between cities.Finally,QAP method was used to study the direction and degree of the influencing factors of air quality correlation in the middle reaches of the Yangtze River.The main conclusions are as follows:(1)the air quality in the middle reaches of the Yangtze river improved year by year from 2015 to 2018,and decreased in 2019.The monthly air quality index(AQI)data showed an obvious symmetrical "U" shape distribution.The monthly peak value of AQI generally appeared in December or January in winter,and the period of poor air quality was from December to the next January.(2)The air quality of urban agglomerations in the middle reaches of the Yangtze River is influenced by each other.The air quality correlation exists generally,and the intensity of the air quality correlation among cities declines first and then increases.Shangrao city,Jingdezhen city,Yingtan city and other cities are at the edge of the network,and it is necessary to strengthen the protection of external pollution transmission.Yueyang city,Changsha city,Xianning city and other cities are in the core position of the network,with greater influence,but also vulnerable to the influence of the surrounding areas.Due to the geographical proximity of cities and other factors,the air quality showed agglomeration effect,and the polarization agglomeration effect of air quality between cities became obvious gradually,which led to the serious differentiation of air quality in the middle reaches of the Yangtze River,showing the characteristics of pollution aggregation such as point source local pollution and comprehensive pollution.(3)Through the QAP method to analyze the influencing factors of the air quality correlation in the middle reaches of the Yangtze River urban agglomeration,it is concluded that the number of industrial enterprises has little influence on the air quality correlation in the middle reaches of the Yangtze River urban agglomeration.Spatial distance,per capita GDP,population density,total LPG gas supply,total gas supply and green space area have a strong negative impact on air quality of urban agglomeration in the middle reaches of the Yangtze River.Based on the research results,the following policy suggestions are put forward:establish a joint air pollution prevention and control mechanism between cities to jointly control air pollution;In order to control the correlation of air pollution,cities should control the coordination of energy use and economic development mode,so as to achieve a win-win situation between economic development and environmental governance.