摘要
根据近四年来北京市空气质量日报的统计,从年度、季度、月份、平日及周末四个时间尺度分析得出:从年度来看,北京市空气质量为二级及二级以上的天数逐年增加,但四五级即中重度污染天气的天数也在逐年增加;从季度来看,主要表现为春季的"沙尘型"和秋冬季常出现的稳定天气下的"积累型"污染;从月份来看,污染天数多集中于1、3、4、10、11月;在平日及周末对比中,发现平日空气质量好于周末。北京市空气污染属于非典型性的复合型污染,污染源构成复杂,以首要污染物可吸入颗粒物为代表的污染物类型中,机动车尾气排放的贡献率不应被高估,应考虑下垫面裸露地人为扰动等因素的影响。
Based on the Beijing daily air quality statistics in the past four years, this paper makes conclusions in accordance with the annual, quarterly, month, weekdays and days scale. The days of below grade two and two are increasing year by year, but the days of grade four and five are also increasing year by year. From the perspective of quarter, it mainly represents the "dust" pollution in spring and the "accumulative" pollution in autumn and winter when the weather system is often stable. In the scale of month, the polluted days are eoncentrated on January, May, April, October and December. Weekdays'air quality is better than weekend days' air quality. Air pollution in Beijing is untypical and compound. The source of pollution is complex. In types of pollutants represented primarily by inhalable particulate matter, automobile exhaust emission is not the decisive factor and human disturbance on the surface should be given consideration.
出处
《城市问题》
CSSCI
北大核心
2008年第12期93-97,共5页
Urban Problems
关键词
时间尺度
可吸入颗粒物
汽车尾气
下垫面
time scale
inhalable particulate matter
automobile-exhaust emission
surface