2007-2014年北京地区PM2.5质量浓度变化特征  

Variation of PM_(2.5) Mass Concentration in Beijing Area during 2007-2014

作　　者：王浩[1,3] 高健[1] 李慧[1,2] 王涵[1] 李轶[3] 王淑兰[1] 柴发合[1] 

机构地区：[1]中国环境科学研究院,环境基准与风险评估国家重点实验室,北京100012 [2]南京信息工程大学,江苏省大气环境与装备技术协同创新中心,江苏南京210044 [3]天津大学理学院,天津300072

出　　处：《环境科学研究》2016年第6期783-790,共8页Research of Environmental Sciences

基　　金：国家自然科学基金项目(41375132,91544226);北京市科技计划项目(Z131100006113013)

摘　　要：为更好地解析北京地区ρ(PM_(2.5))的长期变化特征及气流轨迹聚类分析结果,对2007年8月—2014年7月在中国环境科学研究院实测的ρ(PM_(2.5))数据进行了统计分析,分析其年际、季节和月际变化特征;通过计算PM_(2.5)的AQI分指数,分析了污染等级的时间变化特征;结合后向气流轨迹,对ρ(PM_(2.5))年际、季节变化与气团来源的关系进行了分析.结果表明:北京地区2008—2013年ρ(PM_(2.5))年均值分别为111.5、95.8、94.8、80.5、75.2、81.3μg/m^3,整体呈逐年下降趋势,但污染水平依然较高;ρ(PM_(2.5))由高到低的季节次序为秋季、冬季、春季、夏季,平均值分别为111.6、94.8、77.2、70.5μg/m3,PM_(2.5)重污染时段主要出现在秋冬季节,并且冬季ρ(PM_(2.5))近年来逐渐呈上升趋势;ρ(PM_(2.5))月均值呈单峰型变化,11月最高(为125.3μg/m3),7月最低(为76.4μg/m^3);轨迹聚类分析发现,途经山西省北部和河北省南部的气流轨迹中ρ(PM_(2.5))较高,而来自北方及西北方向的气团相对较清洁,ρ(PM_(2.5))较低.北京地区近些年实施的大气污染减排措施对于控制PM_(2.5)污染取得了一定效果,但针对秋冬季节重污染过程的控制力度仍需要加强,同时也要注意区域污染传输对北京地区ρ(PM_(2.5))的影响.In order to study the long-term variation of PM2.5mass concentration and the results of trajectory clustering analysis in Beijing,PM2.5mass concentration was observed from August 2007 to July 2014 at the site of the Chinese Research Academy of Environmental Sciences in Beijing. The long-term variations of PM2.5mass concentration,seasonal variation and monthly variation were analyzed. By calculating PM2.5AQI index,the temporal distribution characteristics of PM2.5were analyzed at different pollution levels. The results showed that Beijing PM2.5mass concentration showed a declining trend over the past 7 years; the yearly mass concentrations were 111. 5,95. 8,94. 8,80. 5,75. 2 and 81. 3 μg/m^3from 2008 to 2013. In autumn,winter,spring,and summer,the seasonal average concentrations were 111. 6,94. 8,77. 2 and 70. 5 μg/m^3,respectively. The monthly average PM2.5mass concentration presented a unimodal type,that is,the highest concentration was 125. 3 μg/m^3in November,and the lowest concentration was 76. 4 μg/m^3in July.Heavy pollution episodes mainly appeared in autumn and winter.PM2.5was found to be the highest in winter, when the concentration kept increasing. The relationship between PM2.5concentration and air mass origination was built with the help of back trajectory analysis,which were caused by the air masses originated from Hebei Province and those from northern Shanxi Province. The results showed that the pollution control measuresimplemented showed certain effects in Beijing area these years,but autumn and winter heavy pollution process control measures still need to be strengthened,and the local impact on Beijing of regional pollution transfer should be paid more attention to.

关 键 词：北京 PM2.5质量浓度 长期变化 气团来源 

分 类 号：X51[环境科学与工程—环境工程]