2001—2012年北京市API变化趋势分析

Analysis on Trend of API in Beijing in 2001—2012

随着北京雾霾天气的频繁发生,空气质量状况日益受到关注。运用时间序列分析描述方法,描述2001—2012年间北京市的空气污染指数(air pollution index,API)随时间的变化趋势及与降雨量、风速、气温、湿度等气象因素的相关性。结果表明API指数整体呈下降趋势;春季和冬季的月API指数最高,夏季最低,存在明显的季节性,3、4月的月API指数较高,7、8月的月API指数最低;首要污染物中SO2所占的比例在减少,可吸入颗粒物的比例在升高;API指数与降雨量存在负相关关系,与风速、气温、湿度等存在正相关的关系。

As the haze occurred frequently in Beijing, more and more attentions have been paid to air quality. A time series analysis method was used to describe the trend of air pollution index （API） in Beijing in 2001-- 2012, and to find out the correlation of API with precipitation, wind speed, temperature and humidity. There was a declining trend for API index in general, and a significant seasonal variation of API, which was the highest in the spring and winter, and the lowest in the summer; The API was higher in March and April, and lower in July and August. Among the primary pollutants, the proportion of SO2 reduced as the proportion of inhalable particulate mat- ter increased; the API index was negatively correlated with precipitation, and positively correlated with wind speed, temperature and humidity.