Evaluation of Ambient Air Quality of Major Cities in China Based on Principal Component Analysis and Cluster Analysis

In recent years, the issue of ambient air quality has become one of the important issues facing us. With the help of the SPSS software, this paper addresses the air quality problem of 31 major Chinese cities. Selection of annual average concentration of \({\text{SO}}_{{2}}\) , \({\text{NO}}_{{2}}\) , 2019 and 2020 the average annual concentration, the annual average concentration of particulates, the 95th percentile of daily mean value of carbon monoxide concentration, concentration of ozone, maximum 8 h 90th percentile, fine particulate matter the air quality in annual average concentration, and better than 2 days, a total of 14 indicators, using principal component analysis method, the dimensions of 14 indexes were reduced to obtain 2 principal components. Then the principal component scores obtained by principal component analysis were sorted out, and then the K-means clustering method was used to cluster the 31 major cities in China, and finally they were clustered into 3 categories. Finally, the main factors affecting air quality are obtained, as well as the air quality of 31 major cities in China.