Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, China.
PLoS One. 2020 Apr 14;15(4):e0231536. doi: 10.1371/journal.pone.0231536. eCollection 2020.
Urban traffic is an important source of global CO2 emissions. Uncovering the temporal and structural characteristics can provide scientific support to identify the variation regulation and main subjects of urban traffic CO2 emissions. The road class is one of the most important factors influencing the urban traffic CO2 emissions. Based on the annual traffic field monitoring work in 2014 and the localized MOVES model, this study unravels the temporal variation and structural characteristics of the urban traffic CO2 emissions and conducts a comparative analysis of expressway (5R) and arterial road (DB), two typical classes of urban roads in Beijing. Obvious differences exist in the temporal variation characteristics of the traffic CO2 emissions between the expressway and arterial road at the annual, week and daily scales. The annual traffic CO2 emissions at the expressway (5R, with 47271.15 t) are more than ten times than those of the arterial road (DB, with 4139.19 t). Stronger weekly "rest effect" is observed at the expressway than the arterial road. The daily peak time and duration of the traffic CO2 emissions between the two classes of urban roads show significant differences particular in the evening peak. The differences of the structural characteristics between the two classes of urban roads are mainly reflected on the contribution of the public and freight transportation. Passenger vehicles play a predominant role at both the two classes of urban roads. The public transportation contributed more at DB (24.76%) than 5R (5.47%), and the freight transportation contributed more at 5R (23.41%) than DB (3.49%). The results suggest that the influence of traffic CO2 emissions on the CO2 flux is significant at the residential and commercial mixed underlying urban areas with arterial roads (DB) but not significant at the underlying urban park area with expressway (5R) in this study. The vegetation cover in urban areas have effects on the CO2 reduction. Increasing the design and construction of the green space along the urban roads with busy traffic flow will be an effective way to mitigate the urban traffic CO2 emissions and build the low-carbon cities.
城市交通是全球 CO2 排放的一个重要来源。揭示其时间和结构特征可为识别城市交通 CO2 排放的变化规律和主要主体提供科学支撑。道路类型是影响城市交通 CO2 排放的最重要因素之一。本研究基于 2014 年的年度交通现场监测工作和本地化的 MOVES 模型，揭示了城市交通 CO2 排放的时间变化和结构特征，并对北京市两条典型城市道路——高速公路（5R）和主干道（DB）进行了比较分析。高速公路和主干道的交通 CO2 排放的时间变化特征在年度、周和日尺度上均存在明显差异。高速公路（5R，47271.15 吨）的年度交通 CO2 排放量是主干道（DB，4139.19 吨）的十倍以上。高速公路的周“休息效应”比主干道更强。两类城市道路的交通 CO2 排放的日高峰时间和持续时间存在显著差异，特别是在晚高峰时段。两类城市道路的结构特征差异主要体现在公共交通和货运交通的贡献上。两类城市道路的客运车辆均占主导地位。公共交通在 DB（24.76%）中的贡献大于 5R（5.47%），而货运交通在 5R（23.41%）中的贡献大于 DB（3.49%）。结果表明，在本研究中，具有主干道（DB）的居住和商业混合基础城区的交通 CO2 排放对 CO2 通量的影响显著，而具有高速公路（5R）的基础城市公园区的影响不显著。城市植被覆盖对 CO2 减排具有影响。增加交通繁忙的城市道路沿线的绿地设计和建设将是缓解城市交通 CO2 排放和建设低碳城市的有效途径。
