Research On Influencing Factors Of Main Air Pollutants Distribution In Beijing Area

In recent decades,with the high speed rapid development of urbanization in Beijing,industrial supplies,energy consumption and increasing improvement of urban construction,as well as the gross domestic product?GDP?,the urban population and motor vehicle ownership multiplied.At present,urban air pollution has become a crucial environmental problem.In order to further study the occurrence mechanism and influence factors of urban air pollution events,it is necessary to formulate measures for the prevention and control of pollution by air pollution in Beijing.Using12 national environmental quality automatic monitoring station?NS?and 35 level in the whole city environmental quality automatic monitoring station?AS?data sets,combined with the NCEP-GDAS reanalysis data,surface meteorological observation data,etc.,in 2013-2017 in Beijing PM_2.5 continuous monitoring data to conduct a comprehensive analysis,preliminary in this paper,the Beijing area nearly five years space-time evolution characteristics,comparing analysis of two sets of data at the same time,preliminary assessment analysis was carried out on the site layout reasonable,combined with analysis of data during backward trajectory track source and potential pollution source area in Beijing for annual analysis.This study showed that:?1?in the period of data,the PM_2.5 mass concentration in Beijing was decreased year by year,and it was decreased by 7.05?g·m^-?33? every year.The spatial distribution showed a significant trend of south and high north.?2?the pollution of different time scales,the data in the Beijing area during the last pollution incident frequency was more and more small,1-2 pollution time 29 times per year on average,3-4 days 15 times the accident,5-6 days pollution incident occurred 3 times,2 times of 7 days or more pollution event.?3?the data in the Beijing area during the period of PM_2.5 pollution present a significant seasonal characteristics,mass concentration was highest in winter,the spring and autumn times,the lowest in summer,the average annual growth rate change mass concentration of winter largest(the rate of growth of-9.19?g·m^-3·year^-1 was significantly reduced.),and the biggest changed in volatility.?4?two sets of data analysis results showed that the difference between NS,AS monitoring site distribution showed a trend of low meteorological north,north of downtown Beijing NS interpolation data below AS monitoring data to low?0.09?,south of downtown Beijing AS interpolation data below NS monitoring data?0.33?on the high side,the seasonal characteristics of significant difference,the strongest winter differences?0.15?,next autumn,spring,summer was weakest;In winter,the stable weather system increased the error between NS and AS sites,while the process of systematic and strong meteorological conditions reduced the error between state control and city control environmental monitoring data.?5?The PM_2.5pollution in 2017 was better than the previous years,which was related to the spread of meteorological conditions in Beijing and the spread of pollutants in Beijing,as well as the reduction of potential pollution sources in the Beijing area.The scope and weight contribution factor of potential pollution sources in Beijing were decreased in2013-2017.