生态环境学报Issue(5)：797-805,9.
降雨过程后北京城区PM2.5日时空变化研究
Spatial and temporal variation of PM2.5 in Beijing city after rain
摘要
Abstract
With increasing awareness of the environmental protection, residents’ concerns about the city haze weather are increasing at the same time. The spatio-temporal variation of PM2.5 and its impact on human health are becoming the focus of concerns. Previous studies mainly focus on seasonal or yearly variations. This study attempted to explore the characteristics of PM2.5 temporal daily variation and the spatial distribution after rainfall. We collected data of hourly PM2.5 concentrations before and after rainfall in 13 air sampling stations designated by the Beijing Bureau of Environmental Protection and 14 additional samplings sites in Beijing, and analyzed the impact of rainfall on the characteristics of temporal variations of PM2.5. This study further integrated with synchronous meteorological data (temperature, humidity) and traffic data (vehicle volume and speed) to reveal the reasons behind the characteristics of PM2.5 daily variation. The GIS spatial analysis method was subsequently employed to uncover the characteristics of the PM2.5spatial distribution. Results showed that rainfalls efficiently removed particles in the air. A rainfall made the concentration of PM2.5 decreased by an average of 56.3%. PM2.5 concentration was at steady state within 1 hour after rainfall, continued to decline in the next 12 hours and was less than 60μg·m-3 in all 72 hours. The rainfall has significant removal effect on particles with little impact on the diurnal temporal variation curve. The diurnal variation of PM2.5 concentrations exhibited, while the curve was concave type during the day and an arch at night. The peak value appeared at 23 or 0 o’clock and the valley value appeared at 3 pm. This characteristic was greatly influenced by meteorological factors, while traffic contribution is not significant. PM2.5 concentrations were influenced mainly by traffic factors during rush hours in the morning and by both meteorological and traffic factors during rush hours in the evening. The study area on the spatial distribution characteristics of PM2.5 also had marked diurnal variation. The PM2.5 was high in the south and low in the north during the day, and high in the periphery area (outside of the 3rd ring in particular) and low in the center.关键词
降雨/PM2.5/时空变化/空间分析Key words
Precipitation/PM2.5/temporal and spatial variation/spatial analysis分类
资源环境引用本文复制引用
郑晓霞,赵文吉,晏星,赵文慧,熊秋林..降雨过程后北京城区PM2.5日时空变化研究[J].生态环境学报,2014,(5):797-805,9.基金项目
国家青年科学基金项目（41201404）；北京市自然科学基金项目（8133051）；国家基础测绘基金项目（2011A2001）；博士点基金项目 （）
