Air Quality,Urban Development And Interrelation Of Municipalities Directly Under The Central Government In China

In air-quality assessment,PM2.5 is always considered as a measure of air pollution in many research literatures.However,there are many kinds of pollutants in our life so that we need a more comprehensive air pollution index to consider pollutants,which is one of the reason why China has proposed to use the air quality index(AQI)to measure the air quality of a city since 2012;In addition,AQI is used as a value to reflect the air quality of one day,which is easier for ordinary people to accept and pay more attention to the improvement of air quality and pollution control.From the perspective of AQI,considering the four municipalities directly under the central government as the evaluative target,this paper makes more reasonably use of the properties of AQI to evaluate air quality based on the complete seven-year(2014.1-2020.12)AQI data of the evaluative target,and measures their urban development for 21 years;Finally,this paper further discusses the interrelation between urban development and air quality in recent years basing on the previous researches so as to investigate whether China’s municipalities directly under the central government have achieved the goal of that we should not only have golden mountains and silver mountains,but also have green rivers and green mountains in recent years.The main results of this paper are as follows:The first part makes a dynamic analysis of the air quality of the four municipalities by year,month and season by using the method of descriptive statistics,The result shows that the air quality of the four municipalities has been significantly improved in recent years;In addition,the nature of AQI are also used to fit the generalized extreme value distribution,and the commonly used extreme value distribution related property indicators are given to analyze the improvement of air quality.The result also shows that the air quality of them has also been significantly improved under each extreme value characteristic,so the purpose of green water and green mountains has been achieved.In the second part,this paper extracts 11 indicators such as population,economy and greening of the four municipalities directly under the central government from 2000 to 2020 through the study of relevant literature to get the comprehensive score by factor analysis to analyse the dynamic changes of their urban development.The result shows that the four cities are developing upward on the whole,but Shanghai has fallen in the first and middle section,which is obviously affected by relevant factors.In addition,the method of Statistical description is used to compare the development status of them in2019 and 2020.The result shows that the economy of the four municipalities is affected due to the epidemic,of which Chongqing’s the tertiary industry has fallen more,indicating that the economic structure is vulnerable to external events.Chongqing should learn from the development experience of the other three cities to promote its own development and achieve the purpose of both golden mountains and silver mountains.The third part considers the comprehensive indicators(factors)in the second part from 2015 to 2019 as independent variables to measure the development of the city,and the annual mean value or annual extreme mean value of AQI in the first part to measure the air quality of the city in that year.it is concluded that the correlation between air quality and urban development is in a state of negative correlation Using the panel data model;In addition,the scatter diagram(AQI mean factor-comprehensive score)is also used to illustrate that urban development and air quality improvement complement each other in recent years.Obviously,the four municipalities directly under the central government have gone on the road of that we should not only have golden mountains and silver mountains,but also have green rivers and green mountains.