Research On Shanghai Air Quality Index And Pollution Sources

Air quality is one of the hot issues in environmental issues.As a pioneer city in the construction of ecological civilization,Shanghai's air quality has been receiving much attention.With the deepening of reform and opening up,the impact of urban construction on environmental carrying capacity has become more and more serious,and the problem of air pollution has become increasingly prominent.Finding a scientific and reasonable method to describe and predict air quality,can find a basis for improving air quality.Finding pollution sources can prevent pollution from the source and provide a better ecological environment for the citizens.In this paper,the air quality index?AQI?and the time series data of its six main pollutants of Shanghai during January 1,2016 to January 31,2019 are used to evaluate and predict of AQI in the past three years.Firstly,based on the traditional multiple regression and quantile regression methods to study the influence mechanism of each variable.It was found that the coefficients of the quantile regression model of each sequence were significantly different from the least squares regression coefficient.The coefficients of the quantile regression model are only in the 95%confidence interval of the least squares regression coefficient at fewer quantiles.The use of least squares regression to evaluate the effect of each sequence on AQI has certain limitations.Then,the time series quantile regression model?QAR,QADL?is used to comprehensively study the prediction effects of each sequence under different quantile points,and compared with the traditional time series model?AR?prediction results.Finally,QAR and QADL are further optimized?denoted as Sub-QAR,Sub-QADL?to evaluate and predicte AQI.The results show that PM2.5,PM10,CO,NO₂ and O₃ have a significant impact on AQI in addition to SO₂;CO,NO₂ and O₃ have a long-term influence on AQI.The AQI of the previous period has an influence on the current AQI;The average prediction error of AR model for AQI is 57.01%,the average prediction error of QAR model for AQI is 25.82%,and the average prediction error of QADL model for AQI is 24.77%.The average prediction error of Sub-QAR for AQI is 25.18%.The average prediction error of Sub-QADL for AQI is24.23%;the AR model has a larger prediction for future AQI,and the?Sub?QAR and?Sub?QADL models can better predict the value of AQI,among which Sub-QADL The prediction effect of the model is relatively better.It shows that after the model optimization,considering the comprehensive influence of each explanatory variable on AQI,it has better fitting and predicting effect on AQI,and can more accurately identify the dynamic trend and future performance of AQI.This paper uses relevant statistical data to explore the pollution sources of Shanghai AQI.Firstly,the pollution factors of AQI are determined as PM10,PM2.5,SO2,NOx,CO and VOCs.Secondly,the sources of air pollution in Shanghai are divided into point source,line source and surface source.Among them,the point source includes pollutants emitted from the combustion of raw coal,coke,gasoline,diesel,fuel oil and kerosene in the industrial sector.The line source is mainly the pollutants emitted by the exhaust of motor vehicles.The surface source is divided into pollutants emitted by residents'living fuel combustion and six key production process industries in Shanghai,as well as dust generated by the construction industry.Finally,the main sources of pollution of AQI's main pollution factors are studied.The research results show that the main sources of PM10 and PM2.5 are construction dust and production process pollution,among which residential buildings are more polluted,and petrochemical and fine chemical manufacturing and fine steel manufacturing are seriously polluted;The main source of CO and VOCs is manufacturing process.The main source of CO pollution is fine steel manufacturing.The main sources of pollution of VOCs are petrochemical and fine chemical manufacturing and complete equipment manufacturing;The main sources of SO₂ are production process manufacturing,residential fuel combustion and industrial energy combustion.Among them,petrochemical and fine chemical manufacturing and fine steel manufacturing,coal living fuel and industrial coke combustion are the main sources of pollution;The main sources of NOx are production process manufacturing,residential fuel combustion and industrial energy combustion,among which electronic information products manufacturing,residents'natural gas consumption,Raw coal and coke combustion in the industrial sector is the main source of pollution.