降水对京津冀中南部PM_(10)和PM_(2.5)清除作用的分析

Analysis on precipitation scavenging on PM_(10) and PM_(2.5) in central and south of Beijing-Tianjin-Hebei region

利用京津冀中南部10个城市环境监测国控站点的2014～2016年PM_(10)、PM_(2.5)浓度逐小时资料和中国气象局地面观测逐小时国家站降水资料,进行对比统计分析,探讨降水对PM_(10)、PM_(2.5)的湿清除作用。结果表明,京津冀中南部降水对PM_(10)、PM_(2.5)湿清除效果随降雨总量、平均雨强、降水持续时间的增加而加强。当降雨总量大于10mm、平均雨强大于1mm、降水持续时间超过10h时,降水对PM_(10)、PM_(2.5)湿清除效果最佳。降水前PM_(10)、PM_(2.5)浓度与清除率呈非线性正相关关系,随浓度的增加,清除率将趋于稳定。

In this paper,we analyzed the effect of precipitation scavenging PM10 and PM2.5,based on the hourly data of PM10 and PM2.5 in 10 cities in central and south of Beijing-Tianjin-Hebei region,and the hourly precipitation data of the ground observation of China Meteorological Bureau. The results showed that the effect of precipitation on PM10 and PM2.5 was strengthened with the increase of rainfall amount,average rainfall intensity and duration of precipitation. When the total amount of rainfall was greater than 10 mm,the average rainfall was stronger than 1 mm,and the precipitation duration exceeded 10 h,the precipitation had the best effect for PM10 and PM2.5 removal. Pre-precipitation PM10 and PM2.5 concentration and clearance rate did not showed linear relation. With the increase of concentration,the clearance rate tended to be stable.