Time-space Correlation Measurement And Analysis Of Air Quality In China

As people's living standards improved,health issues are more and more valued by people,therefore environmental issues have become the focus of attention.General Secretary Xi Jinping pointed out: We not only need green mountains and rivers,but also need economic growth.We need green mountains and rivers more than need economic growth.And the green mountains and rivers are really wealth.Many related policies for building ecological civilization have also been put on the agenda.This paper is based on the air quality index(AQI)of 25 cities in the Yangtze River Delta in the past three years and the data of various pollution indicators.First of all,the air quality index was descriptive statistical analysis.From a monthly perspective January,February and December in each year are among the highest-polluting air quality indices.From the season point of view,winter air quality is the worst.From an annual average,2016 air quality is better than 2015.According to the statistical results of the air quality indices in different cities,the air quality in Xuzhou is the worst,and the cities with Zhoushan,Lishui,Wenzhou,Taizhou and Ningbo have the fine and excellent rates of more than 90%.From the spatial distribution of air quality point of view,air quality in Jiangsu Province is poor than in most cities in Zhejiang Province,which is worth the concern of the relevant departments.The paper also establishes time series model,panel data model and space panel model for the change of time and space of air quality index.The autoregressive time series model shows that the air quality index is long term stable.From the fixed-effect panel data model,we can see that the change rule of air quality index in different sections or time series is the same except that the intercept item of each city.From the fixed-effect spatial error model,it can be seen that the impact of an individual's air quality index in a certain city will be transmitted to an adjacent individual as a result of this special covariancestructure of the spatial error model,which has the following Long time continuity and gradual attenuation,the spatial effect of air quality has a high order effect.From the impact of economic development on air quality,we learned that improving the coverage of forest trees,reducing the ownership of commercial vehicles and reducing industrial added value are beneficial to improve the ambient air quality.