Comparative Analysis of Air Environmental Quality during 2014-2015 in Guanzhong Area

Air quality and its trend during 2014-2015 were analyzed based on the monitoring data of six air pollutants of six districts in Guanzhong area. The analysis results showed that as the whole year was concerned, PM_2.5 was the major pollutant, followed by PM₁₀, NO₂ and O₃, exhibiting the complex pollution characteristics dominated with particulate pollution. The monthly change feature of PM₁₀, PM_2.5, SO₂, NO₂ and CO concentrations were highest in winter and lowest in summer, while the feature of O₃ was highest in summer and lowest in winter. For each city of the Guanzhong area, the air quality comprehensive index in 2015 was lower than that in 2014. However, the average percentage of days that the air quality meets the Level Ⅱ of National Air Quality Standard in the Guanzhong area is only 71.9%, indicating the status of still severe air pollution. The reduction of emissions in SO₂, NO_x and smoke (powder) dust in the Guanzhong area during 2015 played an important role in air quality improvement, and the air quality was more likely to be directly influenced by the meteorological conditions during the winter heating season.