High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

Shaojun Zhang,Han Yan,Yali Zheng,Ruikun Huang,Ye Wu,Jiming Hao,Jiandong Wang

doi:10.5194/acp-16-9965-2016

Abstract

Abstract. Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach) to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet – Macau, EMBEV–Macau), this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model) model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other vehicle-populated cities in eastern Asia.

Highlights

The soaring vehicle stock driven by socio-economic development has created a series of substantial challenges regarding air pollution, energy insecurity, and public health within many countries (Uherek et al, 2010; Saikawa et al, 2011; Shindell et al, 2011; Walsh, 2014)
If we ignore the potential difference between weekdays and weekends, fleet-average annual vehicle kilometres travelled (VKT) of light-duty passenger vehicle (LDPV) and MCs registered in Macau are 7600 and 4300 km as of 2010, which are quite comparable with our previous survey results
Those values could only be responsible for traffic demand within Macau, considering a part of LDPVs travel across the boundary of the Macau special administrative regions (SAR) into mainland China

Summary

Introduction

The soaring vehicle stock driven by socio-economic development has created a series of substantial challenges regarding air pollution, energy insecurity, and public health within many countries (Uherek et al, 2010; Saikawa et al, 2011; Shindell et al, 2011; Walsh, 2014). In European countries where diesel vehicles make up a considerable part of private passenger cars, near-road NO2 concentration exceeds the ambient air quality standard. This issue is seen as one of the most significant air pollution problems in Europe, great efforts have been made to cope with the NO2 exceedance, including the implementation of stringent emission standards for diesel vehicles (e.g. the latest Euro 6 requirements; Franco et al, 2014; Carslaw et al, 2011; Velders et al, 2011; Carslaw and Rhys-Tyler, 2013; Chen and Borken-Kleefeld, 2014). In 2012, the International Agency for Research on Cancer Group 1 assessed the carcinogenicity of diesel emissions as “carcinogenic to humans” with sufficient evidence for it to be characterized as a cause of lung cancer (Benbrahim-Tellaa et al, 2012)

Methods

Results

Conclusion