北京市区大气污染的时空特征

TEMPORAL AND SPATIAL CHARACTERISTICS OF AIR POLLUTION IN BEIJING

用 1 999年 1 1月 1日到 2 0 0 1年 4月 3 0日SO2 、PM1 0、NO2 、CO和O3等 5类污染物每日大气污染指数和等级资料 ,讨论了北京市区大气污染的时空分布特征。结果表明 :北京市区的污染物以可吸入颗粒物和二氧化硫为主 ,出现 3级以上的概率分别为 5 0 %和 3 0 % ,是相当严重的。北京污染物有明显的季节变化 ,SO2 出现 3级以上概率在冬半年 (1 1月至翌年3月 )为 3 4 % ,夏半年 (4～ 1 0月 )几乎不出现 ,但可吸入颗粒物的季节变化没有其它 4类污染物显著。从 1

Using the daily air pollution index and grade of five contaminants(SO 2, PM10, NO 2,CO and O 3, etc.) from 1 November 1999 to 30 April 2001 in Beijing,the temporal and spatial characteristics of air pollution are discussed. The results indicate: 1) The major air pollutants are PM10 and SO 2,and their occurrence probabilities of Class Ⅲ or higher are 50% and 20%, respectively. 2) There is obvious seasonal variation of the contaminants,for example, the SO 2 probability of ClassⅢ or higher is 34% in the winter half year (November to March)and seldom appears in the summer half year (April to October); however, the seasonal variation of PM10 is not so obvious as other four contaminants. 3) Since 1997,the air quality shows improvement slightly in Beijing.