Inter-urban Haze Pollution In Jing-Jin-Ji Region And Its Influencing Factors Of Dynamic Association

Jing-Jin-Ji Region has become China's most haze-polluted area.Due to the impact of atmospheric circulation and economic development,coupled with the contiguous urban development,the conduction of haze pollution between many cities gradually shows complex network.The research object of this paper is dynamic association of haze pollution between 13 cities in Jing-Jin-Ji Region.Based on social network analysis,this paper examines dynamic association network and its influencing factors of urban haze-pollution in Jing-Jin-Ji Region.First,with the support of ArcGIS platform,this paper draws spatial-differentiation picture of haze pollution in 2015 in Jing-Jin-Ji Region using Krging Interpolation method.Secondly,based on nonlinear Granger causality test,the nonlinear conductive relation of haze pollution is identified.Thirdly,social network analysis reveals the structural features of dynamic network associated with haze pollution.By measuring network density,network correlation,network efficiency,network level degrees,the paper reveals the overall network of dynamic association about haze pollution.Based on the measure of the degree centrality,the betweenness centrality,the closeness centrality,the paper reveals the status and role of different cities in dynamic association network of haze pollution.The core-edge analysis is used to reveal the role and position of each city.Fourth,using QAP analysis examines the influencial factors of dynamic associationof haze pollution.The study found:(1)In 2015,haze pollution in Jing-Jin-Ji Region shows typical spatial disequilibrium.Haze pollution spread from central Hebei province to other regions gradually.The air quality of the northern part is better than the south.(2)Nonlinear Granger causality test results shows the presence of more significant nonlinear conduction relationship between urban haze.(3)Social network analysis shows that urban haze-pollution presents complex network structure with multi-threaded.Network density of the robust network is 0.788,which means that no city can be "orphaned" in the network and haze pollution gradually connect into one piece between urbans.Compared with the robust network,maximum-likelihood network shows more dynamic association relationship with the network density of 0.878,which means more extensive and widespread internet access.Core-edge analysis shows that Qinhuangdao,Xingtai,Shijiazhuang,Handan,Tangshan,Baoding locate in the heart of the network,while Cangzhou,Hengshui,Zhangjiakou,Langfang locate at the edge of the network.(4)Shanxi province and Inner Mongolia create standard deviation impact to the haze pollution in Jing-Jin-Ji Region.Its initial response is positive and experience a rise and fall in trend,wuth closing to 0 after the lag period of 10.(5)QAP regression analysis showed that,[0-250] and [0-300] geographic distance matrix,differences between urban industrial structure,difference between the green area in urban built-up area are the main factors influencing maximum-likelihood network of haze pollution.We should set up a global consciousness,standing in the world to see China and seeing the whole country standing Jing-Jin-Ji Region.And we need re-examine haze pollution in Jing-Jin-Ji Region from a larger perspective and the larger pattern,accelerating the construction of multi-level,cross-regional joint prevention and control system of air pollution,achieving a larger spatial extent of cooperative governance and a collaborative improvement in air quality.