Effects of canyon geometry on the distribution of traffic-related air pollution in a large urban area: Implications of a multi-canyon air pollution dispersion model

Fu, Xiangwen; Liu, Junfeng; Ban-Weiss, George; Zhang, Jiachen; Huang, Xin; Ouyang, Bin; Popoola, Olalekan A. M.; Tao, Shu

doi:10.1016/j.atmosenv.2017.06.031

Cited by 67 publications

(46 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Street canyon design can also affect the dispersion of pollution in cities [15]. While parallel wind within canyons can enhance the dispersion of pollution, Oke et al, [16] argued that perpendicular wind can create a vortex within the canyon.…”

Section: Introductionmentioning

confidence: 99%

Air pollution in a microclimate; the impact of different green barriers on the dispersion

Taleghani

Clark

Swan

et al. 2020

Science of The Total Environment

View full text Add to dashboard Cite

This paper studies the impact of different green barriers on the dispersion of air pollution in a neighbourhood. The study was performed with reference to air quality conditions in Manchester, UK. Manchester experiences a high level of NO2. Measured results showed that the average annual concentration level in 2018 was very close to the limit defined by European Union legislation. Maximum and minimum NO2 concentrations occurred during the winter and summer, respectively. Simulations of the dispersion of air pollution in a hypothetical neighbourhood showed that NO2 level was decreased by the increase of air temperature during the simulated day. In four perturbation scenarios, hedges and trees with different heights were added to the neighbourhood as green barriers. Hedges increased the pollution level near the street at the pedestrian level as a result of the reduced wind speed. The simulations demonstrated that using the trees facilitated the dispersion of pollution.

show abstract

Section: Introductionmentioning

confidence: 99%

Air pollution in a microclimate; the impact of different green barriers on the dispersion

Taleghani

Clark

Swan

et al. 2020

Science of The Total Environment

View full text Add to dashboard Cite

show abstract

“…Scungio et al studied the effects of wind speed and street canyon characteristics on traffic-generated particle diffusion through a CFD simulation, after calculating the excess lifetime cancer risk (ELCR), and found that the ELCR became lower with increasing wind speed [9]. Fu et al studied street canyons in the city center of Beijing and established an urban-scale traffic emission dispersion CFD model [10]. Ultimately, the study pointed out that the canyon geometry had a significant influence on traffic emission concentrations in populated urban areas.…”

Section: Introductionmentioning

confidence: 99%

Modeling Emission Flow Pattern of a Single Cruising Vehicle on Urban Streets with CFD Simulation and Wind Tunnel Validation

Shi

Sun

Zhang

et al. 2020

IJERPH

View full text Add to dashboard Cite

Transportation has become one of the primary sources of urban atmospheric pollutants and it causes severe diseases among city residents. This study focuses on assessing the pollutant dispersion pattern using computational fluid dynamics (CFD) numerical simulation, with the effect and results validated by the results from wind tunnel experiments. First, the wind tunnel experiment was carefully designed to preliminarily assess the flow pattern of vehicle emissions. Next, the spatiotemporal distribution of pollutant concentrations around the motor vehicle was modeled using a CFD numerical simulation. The pollutant concentration contours indicated that the diffusion process of carbon monoxide mainly occurred in the range of 0−2 m above the ground. Meanwhile, to verify the correctness of the CFD simulation, pressure distributions of seven selected points that were perpendicular along the midline of the vehicle surface were obtained from both the wind tunnel experiment and the CFD numerical simulation. The Pearson correlation coefficient between the numerical simulation and the wind tunnel measurement was 0.98, indicating a strong positive correlation. Therefore, the distribution trend of all pressure coefficients in the numerical simulation was considered to be consistent with those from the measurements. The findings of this study could shed light on the concentration distribution of platoon-based vehicles and the future application of CFD simulations to estimate the concentration of pollutants along urban street canyons.

show abstract

“…The CE-DOAS spectral fit is performed in the wavelengths from 435.6 to 455.1 nm, which includes several strong NO 2 and water vapour absorption bands. Reference absorption cross sections of NO 2 (Vandaele et al, 2002), H 2 O (Rothman et al, 2003), glyoxal (CHOCHO) (Volkamer et al, 2005) and O 4 (Hermans et al, 1999) were included in the DOAS fitting.…”

Section: Mobile Cavity-enhanced Doasmentioning

confidence: 99%

“…As described in Sect. 3.2.2, on-road pollutants mainly produced by vehicles and the traffic flow patterns also have a large impact on pollutant distributions (Westerdahl et al, 2005;Kaur et al, 2007;Huan and Kebin, 2012;Rakowska et al, 2014;Fu et al, 2017). The diurnal dependency of the measurement times is corrected for using the simultaneous normalized LP-DOAS measurement.…”

Section: Spatial Distribution Of No 2 In Hong Kongmentioning

confidence: 99%

Analysis of spatial and temporal patterns of on-road NO<sub>2</sub> concentrations in Hong Kong

Zhu¹,

Chan

Lam

et al. 2018

Atmos. Meas. Tech.

View full text Add to dashboard Cite

Abstract. In this paper we present an investigation of the spatial and temporal variability of street-level concentrations of NO2 in Hong Kong as an example of a densely populated megacity with heavy traffic. For the study we use a combination of open-path remote sensing and in situ measurement techniques that allows us to separate temporal changes and spatial patterns and analyse them separately. Two measurement campaigns have been conducted, one in December 2010 and one in March 2017. Each campaign lasted for a week which allowed us to examine diurnal cycles, weekly patterns as well as spatially resolved long-term changes. We combined a long-path differential optical absorption spectroscopy (DOAS) instrument with a cavity-enhanced DOAS and applied several normalizations to the data sets in order to make the different measurement routes comparable. For the analysis of long-term changes we used the entire unfiltered data set and for the comparison of spatial patterns we filtered out the accumulation of NO2 when stopping at traffic lights for focusing on the changes of NO2 spatial distribution instead of comparing traffic flow patterns. For the generation of composite maps the diurnal cycle has been normalized by scaling the mobile data with coinciding citywide path-averaged measurement results. An overall descending trend from 2010 to 2017 could be observed, consistent with the observations of the Ozone Monitoring Instrument (OMI) and the Environment Protection Department (EPD) air quality monitoring network data. However, long-term difference maps show pronounced spatial structures with some areas, e.g. around subway stations, revealing an increasing trend. We could also show that the weekend effect, which for the most part of Hong Kong shows reduced NO2 concentrations on Sundays and to a lesser degree on Saturdays, is reversed around shopping malls. Our study shows that spatial differences have to be considered when discussing citywide trends and can be used to put local point measurements into perspective. The resulting data set provides a better insight into on-road NO2 characteristics in Hong Kong, which helps to identify heavily polluted areas and represents a useful database for urban planning and the design of pollution control measures.

show abstract

Effects of canyon geometry on the distribution of traffic-related air pollution in a large urban area: Implications of a multi-canyon air pollution dispersion model

Cited by 67 publications

References 77 publications

Air pollution in a microclimate; the impact of different green barriers on the dispersion

Air pollution in a microclimate; the impact of different green barriers on the dispersion

Modeling Emission Flow Pattern of a Single Cruising Vehicle on Urban Streets with CFD Simulation and Wind Tunnel Validation

Analysis of spatial and temporal patterns of on-road NO<sub>2</sub> concentrations in Hong Kong

Contact Info

Product

Resources

About

Effects of canyon geometry on the distribution of traffic-related air pollution in a large urban area: Implications of a multi-canyon air pollution dispersion model

Cited by 67 publications

References 77 publications

Air pollution in a microclimate; the impact of different green barriers on the dispersion

Air pollution in a microclimate; the impact of different green barriers on the dispersion

Modeling Emission Flow Pattern of a Single Cruising Vehicle on Urban Streets with CFD Simulation and Wind Tunnel Validation

Analysis of spatial and temporal patterns of on-road NO&lt;sub&gt;2&lt;/sub&gt; concentrations in Hong Kong

Contact Info

Product

Resources

About

Analysis of spatial and temporal patterns of on-road NO<sub>2</sub> concentrations in Hong Kong