近4年安庆地区PM2.5时间分布特征及气象条件分析

Time Distribution Characteristics and Meteorological Conditions of PM2.5 in Anqing of Recent 4 Years

利用2015—2018年安庆市4个国家环境监测站点的PM2.5监测资料,研究该地区PM2.5质量浓度的时间变化特征,了解PM2.5质量浓度的月变化、日变化特征,并利用同期安庆站气象资料分析了PM2.5质量浓度与气象条件的关系。结果表明,安庆市PM2.5质量浓度呈现出冬季高、夏季低的特点,日变化呈双峰单谷型。降水对于PM2.5的清除效果非常显著;风速与PM2.5质量浓度的关系比较复杂,当小时平均风速为1级时,PM2.5质量浓度最高;在冬季,风速越大,PM2.5质量浓度越高;水平能见度在1~4km时,PM2.5质量浓度最高;受到水雾的影响,当能见度低于1km时,PM2.5质量浓度明显下降。

The temporal variation of PM2.5 concentration in Anqing was studied by using the monitoring data of PM2.5 at four national environmental monitoring stations from 2015 to 2018.The monthly and diurnal variations of PM2.5 mass concentration in Anqing area were analyzed,and the relationship between PM2.5 mass concentration and meteorological conditions was analyzed by using meteorological data of Anqing Station in the same period.The results showed that the mass concentration of PM2.5 in Anqing City was high in winter and low in summer,and the diurnal variation was double peak and single valley.The study on the correlation between PM2.5 mass concentration and meteorological conditions shows that precipitation has a very significant effect on PM2.5 removal.The relationship between wind speed and PM2.5 mass concentration is complex.PM2.5 mass concentration is the highest when the average hourly wind speed is 1 grade.In winter,the higher the wind speed is,the higher the mass concentration of PM2.5 is,and the horizontal visibility is 1-4 km.The mass concentration of PM2.5 is the highest,which is affected by water mist.When the visibility is less than 1 km,the mass concentration of PM2.5 decreases obviously.