| Good air quality is a necessary condition for human society to achieve sustainable development.Since the industrial revolution,with the extensive social production,urban air pollution seems to be a nightmare of human beings,and the emergence of urban agglomeration undoubtedly aggravates the degree of air pollution in the city.Since the reform and opening up,the air pollution situation of the urban agglomeration in China has become increasingly prominent.In recent years,haze weather lasting for a long time in many urban agglomerations has been frequent,and the pollution of some urban groups has been very serious.As one of the 11 national urban groups,Guanzhong City Group is also facing with severe challenges of air pollution.If there is no effective policy intervention,the air pollution in recent years has been obviously increasing year by year.At present,with the implementation of relevant policies and standards,the momentum of air pollution has been preliminarily controlled.What's more,the monitoring and data acquisition of air quality have become more scientific and effective.The production of mass air quality data makes it possible to do more detailed analysis of pollution laws and the effect evaluation of the air pollution control policy.This paper uses the high frequency air quality index(AQI)data and the concentration data of six pollutants SO2,CO,NO2,O3,PM2.5 and PM10 of Guanzhong City Group from 2015 to 2017.And analyzes the urban agglomeration including Xi'an,Xianyang,Tongchuan,Baoji and Weinan from two aspects.On the one hand,by using descriptive statistics,constructing hour index and VAR model to analyze the air pollution law of urban agglomeration in Guanzhong area.On the other hand,through comparing and analyzing of DID model to evaluate the policy effect of "1 + 9”action plan.The research results show that:(1)The overall air pollution situation of Guanzhong City Group is severe,and if there is no policy intervention,the air pollution in each city has been aggravated.Moreover,the concentration fluctuation of the main pollutants has obvious seasonal and intra day laws.For example,PM2.5 pollution is heavier in winter than in summer,at night is heavier than day,and its concentration is relatively lowest in one day at about 17 p.m.While O3 pollution is heavier in summer than in winter,daytime is heavier than night,and its concentration is relatively highest at about 16 p.m.(2)Air pollution in different cities has obvious association rules.Take PM2.5 as an example,the fluctuation of a city's air pollution will cause the same direction pollution to other cities.The impact will increase rapidly,reach the peak value,then gradually decay to zero.Moreover,the peak of the impact will decrease with the increase of the distance between cities.The time needed for reaching the peak will become longer with the increase of the distance between cities.(3)The implementation of the "1+9" action plan has significantly improved the air quality of autumn and winter in every city.The implementation of the scheme has significant effects on the PM2.5 governance in five cities during the autumn and winter heavy pollution months.The policy effect of Xi'an is the strongest,followed by Xianyang and Weinan,while Baoji and Tongchuan are weaker.(4)The implementation of the "1+9" action plan is not successful for O3 pollution control in all cities.After the implementation of the plan,the degree of O3 pollution in five cities did not decrease,but increase all,Xi'an,Xianyang and Weinan increased significantly. |
PDF Full Text Request