| With the development of our social economy in China,the level of our material life is continuously improving.At the same time,it also brings serious environmental pollution.To solve this problem,China put forward national policy of constructing ecological civilization and green development and invested a lot of human,material and financial resources in environmental government and has made remarkable achievements.This paper choosed the air quality data of China's 113 key environmental protection cities from 2013 to 2018,clustered these data using several clustering methods with R,analyzed and compared several clustering results.In general,the results of these clustering methods are consistent.Then,this paper analyzed the air quality data of key environmental protection cities in 2018 using principal component analysis(PCA),the six index variables are roughly integrated into two main components: pollutant concentration and pollutant source difference.Then,factor analysis is conducted according to the correlation between variables,and it is found that automobile exhaust and dust pollution factor,coal pollution are important factors for air pollution.Espeically a new sorting method by means of the sum of squares of principal component loadings was put forward based on the thinking of communalities of factor analysis.It was implemented with R.The first advantage of the new method is that the samples which have larger absolute value of loadings on every principal component are highlighted and are made come top.Then the influence of the sign which are in front of unit feature vector is eliminated.This advantage eliminates scores ranking's nonuniqueness which is caused by direct summation.It also doesn't need to weight or standardize the contributing rate of the variance of the principal components to avoid data distortion.Starting with regional distribution and chronological order,this paper also made a detailed analysis of air quality data of key cities of national environmental protection,province cities and parts of representative cities(sorting by days of air quality which is reaching or better than level 2(G-day)).The results show that the distribution of these key environmental protection cities is obviously regional from the perspective of geographical distribution.The cities with serious air pollution are mainly concentrated in North China and Northwest China.The air quality of the southern cities is better than that of the northern cities as a whole.Among every factor that affects the seven indicators,sulfer dioxide(SO2)and carbon monoxide(CO)are mainly affected by coal-fired(such as winter coal heating)and industrial combustion emissions(such as thermal power generation).The correlation between SO2 and CO is strong;the correlation between NO2,PM10,O3 and PM2.5 is strong,and the pollution source is roughly related to automobile exhaust and construction dust.From the double coordinate chart of air quality data of 113 key environmental protection cities,the air pollution types of each city can be seen.But from the perspective of chronological order,we can see that the air quality of 113 key environmental protection cities in China has improved significantly in recent years,which embodies in the year-by-year increase of G-day in most cities and the year-byyear decrease of SO2,NO2,PM10 and PM2.5.In particular,the three-dimensional line chart,three-dimensional curved surface frame chart and three-dimensional bar chart drawn by the above three types of urban air quality monitoring data directly reflect the main characteristics of urban air quality data in China changing with time,which are vivid and easy to analyze and explain.This paper analyzed the reasons for this good momentum,affirmed the great achievements of the national strategy of constructing ecological civilization,green and low-carbon development in recent years,and made some suggestions for the current existing problems and future governance. |
PDF Full Text Request