北京市PM2.5和PM10季节变化特征与空间差异分析

Analysis on Seasonal Variation Characteristics and Spatial Differences of PM2.5 and PM10 in Beijing

基于北京市地面监测站2014年5月1日—2015年4月30日的空气质量数据,参照风速、相对湿度、降雨量等气象因子,对大气颗粒物的季节变化特征进行综合分析,结合后向轨迹模型,分析春季沙尘暴天气的污染物来源;利用克里金插值对PM2.5和PM10进行空间表达,分析其空间差异。结果表明:(1)北京市PM2.5和PM10年平均质量浓度分别为78、111μg·m^-3,空间上由南向北递减;(2)PM2.5质量浓度春、秋、冬季较高,夏季最低,PM10按春、冬、秋、夏季依次降低;(3)PM2.5和PM10月均质量浓度均呈波浪型变化,10月是两者共同高峰值;(4)冬季远郊/山区站的PM2.5月均质量浓度显著高于中心城区站和卫星城区站。

Based on the air quality data from the ground monitoring stations in Beijing during May.1,2014 and Apr.30,2015,we carried out a comprehensive analysis of the seasonal variation characteristics of atmospheric particulates with reference to meteorological factors,such as wind speed,relative humidity,rainfall,etc.Then we analyzed the source of pollutants of spring sandstorm combined with the backward trajectory model.Further,we employed the Kriging interpolation in the spatial expression of PM2.5 and PM10 to analyze their spatial differences.As the results show that the annual average concentrations of PM2.5and PM10 in Beijing are 78μg·m-3and 111μg·m-3respectively,both decreasing spatially from south to north.The PM2.5 concentration is higher in spring,autumn and winter,and reaches its lowest in summer,while the PM10 concentration decreases in the order of spring,winter,autumn and summer.The monthly average concentrations of PM2.5 and PM10 change in a wave form,both peaking in October.The monthly average concentration of PM2.5 in winter is higher in the suburbs/mountainous stations than that in the central city stations and the satellite town stations.