摘要
城市人居环境中的大气颗粒物污染已经成为人类面临的主要环境问题之一。街谷是现代城市的重要空间形式与特征之一,是城市各种公共空间中使用频率最高、汽车尾气污染最严重、日常人口密度最大的公共空间类型之一。城市街谷的几何形态对大气颗粒物的扩散起着关键作用。本研究运用ENVI-met模拟软件,以沈阳的气象条件为研究背景,理想状态下的行道树为研究对象,分析了3种街谷高宽比(H/W=0.5、1和2)、3种街谷走向(NE-SW、NW-SE、E-W)和2种行道树(杨树、松树)对街谷内大气颗粒物PM_(2.5)分布特征的影响。结果表明:PM_(2.5)日变化呈现出"双峰双谷"的趋势。街谷高宽比对PM_(2.5)浓度具有显著影响,其中高宽比为1的街谷中PM_(2.5)浓度最高。同方向、同高宽比街谷下,不同种类的行道树的PM_(2.5)浓度具有显著性差异,行道树的种植对街谷中行人高度的大气细颗粒物的减缓起着一定的负面作用。
The pollution of atmospheric particulate matter in urban human settlements is one ofthe major environmental problems faced by human beings.Street canyon is one of the most impor-tant space forms and characteristics of modern cities,with the highest frequency of utilization,the most serious pollution by automobile exhaust,and the highest population density.The geome-try of urban street canyons plays a crucial role in the dispersion of atmospheric particulate mat-ters.Here,we quantified the impacts of street trees on the distribution of atmospheric particulatematter PM_(2.5)in the street canyons of Shenyang,China.Meteorological parameters and distributionof street trees were used in ENVI-met software with three aspect ratios(H/W=0.5,1 and 2),three street canyon directions(NE-SW,NW-SE,E-W),two kinds of street trees(poplar andpine).The diurnal variation of PM_(2.5)showed a trend of“two peaks and two valleys”.The aspectratio of street canyons had a significant effect on the concentration of PM_(2.5),with the highest val-ues in street canyons with an aspect ratio of 1.However,there were obvious differences in thePM_(2.5)of different types of street trees under street canyons in the same direction and the sameaspect ratio.Our results suggest that street trees have negative effects on the reduction of atmos-pheric fine particulate matters at pedestrian heights in the street canyons.
作者
李苹苹
苗纯萍
陈玮
胡远满
何兴元
LI Ping-ping;MIAO Chun-ping;CHEN Wei;HU Yuan-man;HE Xing-yuan(CAS Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;University of Chinese Academy of Sciences,Shenyang 110016,China;Shenyang Arboretum,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第12期4044-4052,共9页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41801187,41730647)资助。
