北京市近12年空气污染变化特征及其与气象要素的相关性分析

以北京市近12年空气污染指数(API)为数据基础,首先分析了2001—2012年北京市API、污染等级、首要污染物的变化特征以及污染天数年度值、季度值、月值的变化特征;然后根据API转换得到PM10质量浓度,对其变化特征进行分析;最后采用相关系数法分析了北京市API、PM10质量浓度与气象因素的相关性。结果表明,北京市近12年空气污染天数有明显下降趋势,首要污染物主要为可吸入颗粒物;空气污染主要集中于春季,优良天气主要集中于夏季;PM10质量浓度年度最大值出现在2006年,季度最大、最小值分别出现在春、夏季,月值最大、最小值分别出现在3月和7月;气象因素与空气污染关系密切,气温、相对湿度、降雨量与污染天数和PM10质量浓度均呈显著负相关,而风速与污染天数和PM10质量浓度则呈显著正相关。

Air pollution variation characteristics and its correlation with meteorological data in Beijing in recent 12 years

Based on the air pollution index (API) data of Beijing in the past 12 years, we first analyzed the change features of API, pollution level, primary pollutants, and annual value, quarterly value and monthly value of pollution days. Then, we converted API into PM10 mass concentration and analyzed its change features. Finally, the correlation coefficient method was adopted to analyze the relevancy among API, PM10 mass concentration and meteorological factors of Beijing. The results indicated that the number of pollution days in the past 12 years presented a notable downtrend, and the primary pollutants were inhalable particles; the air pollution was concentrated in spring, and good weather was concentrated in summer. The maximum annual value of PM10 mass concentration appeared in 2006, the maximum and minimum quarterly values appeared in spring and summer, respectively, and the maximum and minimum monthly values appeared in March and July, respectively. Meteorological factors were closely associated with air pollution: temperature, relative humidity, and precipitation were in significant negative correlation with pollution days and PM10 mass concentration, and wind speed were in significant positive correlation with pollution days and PM10 mass concentration.