北京市无风天人体高度的PM2.5、PM10变化特征及扩散机制研究  

Study on the variation characteristic of PM_(2.5),PM_(10) at the body height in breezeless day of Beijing and diffusion mechanism

作　　者：葛秀秀[1] 熊黑钢[2] 张南[1] 朱忠鹏[1] 石雪颖 周晓曦[1] 

机构地区：[1]新疆大学资源与环境科学学院,教育部绿洲生态重点实验室,新疆乌鲁木齐830046 [2]北京联合大学应用文理学院,北京100083

出　　处：《环境污染与防治》2017年第1期63-69,共7页Environmental Pollution & Control

基　　金：国家自然科学基金资助项目(No.41271185);北京市属高等学校高层次人才引进与培养计划项目(No.IDHT20130322)

摘　　要：为了解无风天情况下PM_(2.5)、PM_(10)的人体暴露水平及扩散机制,对人体呼吸高度的PM_(2.5)、PM_(10)浓度及近地面不同高度处的温度、相对湿度进行连续监测,分析了垂直温度梯度、相对湿度的相对变化速率对PM_(2.5)、PM_(10)浓度的影响,并利用回归分析法建立PM_(2.5)、PM_(10)浓度与不同高度处温度、相对湿度的单、多变量回归模型,从中选取最优回归模型。结果表明:(1)晴天的PM_(2.5)、PM_(10)浓度在研究时段(9:00—21:00)内总体呈先降低再升高的趋势,而阴天、小雨天PM_(2.5)、PM_(10)浓度呈多峰变化,起伏较大;晴天不同高度的温度差异大,阴天、小雨天温度差异相对较小;晴天不同高度的相对湿度曲线总体均呈U型分布,相较而言,阴天及小雨天各层的相对湿度曲线波动较大;(2)垂直温度梯度是影响晴天PM_(2.5)、PM_(10)扩散的主要原因,相对湿度变化是影响颗粒物扩散的另一重要因素。(3)PM_(2.5)、PM_(10)浓度的单、多变量最优回归模型表明,低污染晴天,温度是影响颗粒物扩散的主要因素,高污染晴天则主要受相对湿度的影响,介于上述两种污染状况之间时,PM_(2.5)、PM_(10)浓度不仅受各层相对湿度的控制,还受到温度的影响。阴天PM_(2.5)、PM_(10)浓度的最优回归模型相对复杂,模型精度不及晴天。In order to understand the human exposure level and diffusion mechanism of PM2.5 and PM10 in the breezeless day,the PM2.5 ,PM10 concentration at body respiration height and the temperature and relative humidity at different height near the ground were continuous monitored, the effects of vertical temperature gradient and relative humidity changing rate on PM2.5 and PMI0 concentration were analyzed. Finally, the regression analysis was used to establish the univariate and multivariate regression models of PM2.5 and PM10 concentration using temperature and relative humidity at different altitudes,and the optimal regression model was selected. The results showed that： （1） the concentration of PM2.5 and PM10 in sunny days showed a trend of decrease first and then rise again during the study period （9：00-21：00） ,while on cloudy and rainy days,the concentrations of PM2.5 and PM10 were multi-peaked and un- dulating. The difference of temperature in sunny days was greater,and the temperature difference in rainy days was relatively small, the relative humidity curves at different altitudes in sunny days were showed an overall U-shaped, in contrast,the relative humidity curves in cloudy and light rainy days fluctuate greatly. （2） The vertical temperature gradient was the main reason for PM2.5 and PM10 diffusion in sunny days,and the relative humidity changing rate was another important factor. （3） Optimal univariate and multivariate regression models of PM2.5, PM10 showed that in low-pollution sunny days, the temperature was the main factor affecting the spread of particulate matter, high pollution sunny days were mainly affected by the relative humidity, between the two kinds of pollution, PM2.5, PM10 were affected by both relative humidity and temperature. The optimal regression model of PM2.5 and PM10 in cloudy day was relatively complex,and the precision of model was less than that of sunny days.

关 键 词：PM2.5 PM10 无风天 扩散机制 

分 类 号：X513[环境科学与工程—环境工程]