乌鲁木齐城市空气质量状况与常规气象条件的关系

Assessment on Air Quality in Urumqi and Its Relation with Meteorological Conditions

依据2009-2011年乌鲁木齐市空气污染指数(air pollution index,API)日报数据和相应时段的常规地面气象资料,利用相关统计法分析了城市空气质量与气象要素之间的关系。结果表明,随着城市治理空气污染一系列项目的开展,空气质量有转好的趋势。3年间空气质量以Ⅱ级和Ⅲ级天气为主,其中Ⅱ级天气出现的天数占统计天数的66.48%,Ⅲ级天气出现的天数占统计天数的22.29%;空气质量具有明显的季节特征,冬季空气质量最差,夏季最好;首要污染物为PM10,其中SO2为首要污染的天数在冬季开始增加,这表明城市冬季空气污染以"烟煤"型为主;API指数与气温、风速、能见度和湿度等气象因素关系密切,API值与气温、能见度和风速呈负相关,与湿度呈正相关。采暖期污染源的排放和不利于污染物扩散的气象条件是影响该市空气质量的两大重要因素。

Based on the monitoring air environmental and ground meteoro- logical data of APl（air pollution index）, the characteristics of the air quality in U- rumqi during 2009-2011 were analyzed, and the relationships between the API and ground meteorological factors were discussed. The results indicated that the air quality had been improved evidently due to some effective air quality regula- tions taken in recent three years. The grade of II and III air quality primarily occurred in Urumqi. Grade II and grade Ill was partly accounted for 66.48% and 22.29% in statistical days. The seasonal variation of air quality was distinct. The most serious air pollution occurred in winter. The primary pollutant was PM. Sulfur dioxide pollution began increasing in winter, showing that Urumqi belonged to a typical coal smoke pollution city. The meteorological factors impact air quality was significant such as tempera- ture, visibility, wind and humidity, also impacted by the inversion layer and at- mospheric stability. There was a strong negative correlation between the API in- dex and temperature, visibility, wind ve- locity, and a positive correlation with hu- midity. The two important factors which influenced the air quality were the period of heating pollution source emission and badly conducive meteorological factors for the spread of pollutants.