Research On The Spatio-Temporal Correlation Effects Of Atmospheric Pollutants In Beijing-Tianjin-Hebei Region Based On Multiplex Network

At present,the atmospheric pollution in China is quite serious,especially in the Beijing-Tianjin-Hebei Region.The spatial process of the heavy atmospheric pollution's transmission in the region is complicated because of the high intensity emissions,adverse geographical and meteorological conditions.The situation of atmospheric pollutants' control is grim.The key to improving air quality lies in controlling the transmission and linkage of pollutants.The transport paths of pollutants can be studied from the perspectives of "one pollutant conducting within multiple areas" and "multiple pollutants conducting within one area".Corresponding control measures can also be taken from these two perspectives.Based on the method of multiplex network,the spatio-temporal correlation model has been constructed from the relationship among "time-space-kinds".In this paper,nearly 100,000 overload indexes are substituted into the model.The data came from the average daily monitoring values of six major atmospheric pollutants form the cities with in the Beijing-Tianjin-Hebei Region from December 2013 to April 2017.On one hand,the spatio-temporal correlation of interregional pollutants' conduction has been studied from a "multiple areas" perspective.On the other hand,the spatio-temporal correlation of the linkage of multiple pollutants within one area has been studied from the perspective of "multiple pollutants".Finally,the spatio-temporal correlation effect of multiple pollutants' linkage and multiple areas' conduction in Beijing-Tianjin-Hebei Region was comprehensively investigated.The main research contents and innovations of this paper are as follows.(1)A "time-space" correlation model of single pollutant conduction between regions is established.A series of conducting networks have been studied which are consisting of the overload indexes of a single pollutant in the atmosphere.These spatial relationships are based on some specific temporal relationships.The static contemporaneous correlation and lead-lag relationship between them have been analyzed.The dynamic evolution characteristics of the interregional conducting networks of one single pollutant are explored.Key cities and urban groups who play a key role in the conduction have been identified.(2)A "time-kind" correlation model of multiple pollutants in one region is constructed.Through the networks build of overload indexes of multiple atmospheric pollutants,the relationship between leading and lagging of multiple pollutants which conducting in one area is analyzed.These intraregional linkage networks have been constructed in different time scenarios.Important features of the dynamic evolution of multiple pollutants within one area have been explored.Pollutants and their combinations in the area have been found which play a key role.(3)A "time-space-kind" correlation model is established for the conduction of variouspollutants in the atmosphere over multiple areas.Multiple paths are identified by the critical path recognition algorithm of multiplex network.These paths include long-cycle static paths and summer-fall/winter-spring dynamic paths based on leading/lagging roles.They are all the key pathways for the conduction and linkage of various pollutants in Beijing-Tianjin-Hebei Region.For one specific pollutant concentration reduction target,the preliminary task to achieve the target and the benefit after achieving the target have been calculated.A series of policy proposals on coordinated management of the Beijing-Tianjin-Hebei Regional atmospheric environment have been put forward.