城市街谷内PM_(2.5)浓度时空变化及影响因素分析  

Temporal and spatial characteristics of PM_(2.5) concentration in urban street canyons and analysis on the affecting factors

作　　者：张云伟[1] 王晴茹 陈嘉[1] 刘随心[2] 胡塔峰[2] 顾兆林[1] 

机构地区：[1]西安交通大学人居环境与建筑工程学院,陕西西安710049 [2]中国科学院地球环境研究所,陕西西安710077

出　　处：《中国环境科学》2016年第10期2944-2949,共6页China Environmental Science

基　　金：国家自然科学基金(51508458;11572242);中央高校基本科研专项项目(xjj2014054)

摘　　要：通过现场观测研究西安市和平路街谷内的PM_（2.5）浓度时空变化特征及其影响因素.在2015年4月8-10日进行了街谷内PM_（2.5）浓度、车流量、风速、温湿度等参数的日变化规律和PM_（2.5）浓度空间分布规律的观测实验.观测结果显示西安市和平路街谷内PM_（2.5）浓度值较高,日间PM_（2.5）浓度呈＂凹＂字形变化,早晚PM_（2.5）浓度相对较高,在16：00前后PM_（2.5）浓度到达一天当中的最低值.PM_（2.5）浓度与温度、湿度有良好的相关性,对应R2值分别达到0.75和0.81.静风天气条件下,由温度变化引起的大气边界层伸缩运动被发现是影响街谷内污染物扩散的主要因素.In the current work, temporal variations of PMz5 concentration, traffic flux, wind speed, air temperature ana humidity was measured on Heping Road, which well represents an urban the street canyon, during April 8-10, 2015, in Xi＇an. Based on these measurements, diurnal and spatial variations of PM2.5 in the urban street canyon and the affecting factors were investigated. Generally, PM2.5 concentrations were found very high in the street canyon, especially in the morning and evening. The lowest PM2.5 concentrations were observed at 16：00 in the daytime. Good correlations were found between PM2.5 concentration and air temperature and/or humidity, with R2 values of 0.75 and 0.81, respectively. Under weak wind conditions, the temperature variation induced expansion and contraction was found to be the main influencing factor on pollutant dispersion in urban street canyons.

关 键 词：PM2.5浓度 街谷 气象因子 相关性 

分 类 号：X169[环境科学与工程—环境科学]