I. Introduction to the Comprehensive Air Quality Index:
1. The comprehensive air quality index is a tool used by the Ministry of Environmental Protection of China to evaluate and rank the air quality of 74 key cities.
2. The comprehensive index of air quality, also known as the comprehensive index of ambient air quality, is a dimensionless index that describes the comprehensive situation of urban ambient air quality. Considering the pollution levels of six pollutants, such as SO2, NO2, PM 10, PM2.5, CO and O3, stipulated in Technical Specification for Ambient Air Quality Index (Trial), the greater the comprehensive air quality index, the heavier the comprehensive pollution level.
Second, the calculation method:
1, which can simply describe the sum of the quotient of the concentration of six pollutants in the evaluation period of the algorithm and the corresponding secondary standard value in one sentence, according to the ambient air quality standard.
2. Calculate the statistical concentration values of pollutants, and make statistics on SO2, NO2, PM 10 and PM2.5 in each city. Calculate the 95th percentile of daily average value of carbon monoxide and the 90th percentile of maximum 8-hour value of ozone.
3. The concentration value of Ci pollutants, when I is SO2, NO2, PM 10, PM2.5, Ci is the monthly average, and when I is CO and O3, CI is the corresponding percentile concentration value.