北京市大气污染物浓度空间分布与优化布点研究

The Study on Spatial Distribution of Atmospheric Contaminant Concentrations and Optimization of Air Quality Monitoring Sites in Beijing City

基于地统计学方法对北京市2012年11-12月的大气污染物SO2、NO2、PM10和PM25浓度数据进行了空间分析.结果表明,4种污染物浓度数据均符合正态分布,满足地统计学分析的使用条件且均呈现中等强度的变异性.4种污染物半变异函数的块金效应值分别是29％、24％、7％、4％,表现出很强的空间相关性.4种污染物长轴变程分别是63、58、62、90 km,短轴变程分别是31、37、48、50 km,空间分布呈现出各向异性,变程范围与中尺度天气系统相当.研究大气污染物的空间分布特性对于整体把握区域环境空气质量和监测点位优化十分重要,以北京市区域空气质量中PM2.5监测站点设置为例,其监测站点在长轴方向上的间隔设置应取20 - 25 km,短轴方向上布点间隔应为8- 12 km.

The spatial analysis of the SO2, NO2, PMto, and PM25 concentrations data collected from air quality automaticmonitoring network of Beijing during Nov. to Dec. 2012 were based on the geo-statistics method. The results show that the dataare all subordinated to normal distribution that meets the prerequisite of geo-statistical analysis, with a moderate intensity spatialvariability. The nugget effect values of the semivariogram fitting parameters of the four pollutants are 29% , 24% , 7% and 4% ,respectively. The nugget effect values reveal that they all have strong spatial relevance. It exhibits anisotropic distributiontotally, 63, 58, 62, 90 km the major ranges and 31, 37, 48, 50 km the minor ranges of the four pollutants. The range scopeand mesoscale weather systems are quite. Studying on the spatial distribution of air pollutants is very important to integrally graspthe regional environmental air quality and carry out monitoring sites optimization. As the example of setting the PM2 5 monitoringsites of regional air quality in Beijing, it suggests that the theoretical sampling interval should be about 20-25 km at the directionof major ranges, while should be about 8-12 km at the direction of minor ranges.