济南市空气质量特征分析

根据济南市2001～2005年的空气质量日报资料,分析了济南市空气质量特征及其成因。结果表明,济南市近5年平均空气污染指数为96.2,良好率仅占64.7%,轻微污染和轻度污染每年平均124.8天,5年中中度污染以上天数为20天,空气污染总体较为严重。风速的大小与每日空气污染指数之间的关系近似呈U形分布特点,2m/s以下微风或静风会抑制污染物质的扩散、使污染物积聚,污染较重。在风速大于6m/s时,由于地面灰尘的扬起或上游沙尘的侵入,使空气中的可吸入颗粒物浓度再次升高。当地面风速在2～6m/s时,污染物浓度相对较低。中度以上的污染一种产生在气旋南部和冷锋前后,伴随风力较大、产生沙尘和扬沙天气,另一种伴有小风,在大气中悬浮着烟雾。空气质量为优的清洁日主要受冷锋后部的冷高压影响。

Characteristic Analysis of Air Quality in Jinan

The characteristics of air quality in Jinan are studied on the basis of the daily air pollution index(API)from 2001 to 2005.The average API was 96.2 for the period,and the number of days with good air quality accounted for 64.7%.Annual average numbers of days with slight pollution and middle pollution were 124.8 and 20 in the 5 year period,respectively.As a whole,the city is relatively polluted.The relationship of API and wind speed in Jinan has a U-shaped curve,with higher APIs at the wind speeds being less than 2 m/s and higher than 6 m/s and with lower APIs at the wind speeds in the range of 2 to 6 m/s.The moderate or above pollution was caused mainly by weather:sand storms or blowing sands followed by cyclones and cold fronts,and smog or fog followed by breeze.Clear air days were mainly accompanied with the weathers patterns affected by the rearward of cold fronts or cold highs.