Analysis on the Variation Characteristics of PM_2.5 and PM₁₀ Mass Concentration in Kunming City

According to the monitoring data of atmospheric pollutants PM_2.5 and PM₁₀ in Kunming in 2017,the variation characteristics of PM_2.5 and PM₁₀ concentration and the proportion of PM_2.5 and PM₁₀ and the correlation between them were analyzed. The results showed that the mass concentrations of PM_2.5 and PM₁₀ were significantly higher in winter and spring than in summer and autumn,and the highest concentration of PM_2.5 in winter was33. 25μg/m³,and the highest concentration of PM₁₀ in spring was 68. 24μg/m³. The peak mass concentration values of PM_2.5 and PM₁₀ appeared at 9∶ 00 am and 1∶ 00 am,and the lowest values appeared at 16∶ 00 pm and 17∶ 00 pm. The ratio of PM_2.5/PM₁₀ ranges from 0. 436 to 0. 558 with the highest winter average of 0. 505,indicating that the proportion of PM_2.5 in winter pollutants is high. There is a very significant linear correlation between PM_2.5 and PM₁₀ daily average,and the correlation coefficient R² is 0. 853.