DOI: 10.1016/j.atmosenv.2014.10.002
Scopus记录号: 2-s2.0-84907996360
论文题名: Evaluation of impacts of trees on PM2.5 dispersion in urban streets
作者: Jin S ; , Guo J ; , Wheeler S ; , Kan L ; , Che S
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 99 起始页码: 277
结束页码: 287
语种: 英语
英文关键词: Air pollution
; Canopy density
; Green street planning
; Leaf area index
; PM2.5
; Urban street canyon
; Wind speed
Scopus关键词: Canopy density
; Leaf Area Index
; Urban street canyon
; Urban streets
; Wind speed
; Air pollution
; concentration (composition)
; environmental protection
; parameterization
; particulate matter
; pollution control
; pollution monitoring
; simulation
; tree
; urban area
; air pollution
; Article
; canopy
; concentration (parameters)
; density
; dispersion
; haze
; leaf area
; particulate matter
; reduction
; regression analysis
; residential area
; seasonal variation
; tree
; urban area
; velocity
; wind
; China
; Shanghai
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: Reducing airborne particulate matter (PM), especially PM2.5 (PM with aerodynamic diameters of 2.5μm or less), in urban street canyons is critical to the health of central city population. Tree-planting in urban street canyons is a double-edged sword, providing landscape benefits while inevitably resulting in PM2.5 concentrating at street level, thus showing negative environmental effects. Thereby, it is necessary to quantify the impact of trees on PM2.5 dispersion and obtain the optimum structure of street trees for minimizing the PM2.5 concentration in street canyons. However, most of the previous findings in this field were derived from wind tunnel or numerical simulation rather than on-site measuring data. In this study, a seasonal investigation was performed in six typical street canyons in the residential area of central Shanghai, which has been suffering from haze pollution while having large numbers of green streets. We monitored and measured PM2.5 concentrations at five heights, structural parameters of street trees and weather. For tree-free street canyons, declining PM2.5 concentrations were found with increasing height. However, in presence of trees the reduction rate of PM2.5 concentrations was less pronounced, and for some cases, the concentrations even increased at the top of street canyons, indicating tree canopies are trapping PM2.5. To quantify the decrease of PM2.5 reduction rate, we developed the attenuation coefficient of PM2.5 (PMAC). The wind speed was significantly lower in street canyons with trees than in tree-free ones. A mixed-effects model indicated that canopy density (CD), leaf area index (LAI), rate of change of wind speed were the most significant predictors influencing PMAC. Further regression analysis showed that in order to balance both environmental and landscape benefits of green streets, the optimum range of CD and LAI was 50%-60% and 1.5-2.0 respectively. We concluded by suggesting an optimized tree-planting pattern and discussing strategies for a better green streets planning and pruning. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/80601
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Landscape Architecture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China; Department of Human Ecology, University of California, Davis, CA, United States
Recommended Citation:
Jin S,, Guo J,, Wheeler S,et al. Evaluation of impacts of trees on PM2.5 dispersion in urban streets[J]. Atmospheric Environment,2014-01-01,99