城市客运交通方式碳排放强度比较

Comparison of carbon emission intensities across different urban passenger transport modes

为比较不同城市客运交通方式的碳排放水平,提出城市客运交通碳排放强度评价指标,构建城市客运交通碳排放强度测算模型,结合Kruskal-Wallis检验和Bonferroni校正方法,分析不同城市客运交通方式碳排放强度的显著差异性,并采用k-means聚类方法,研究不同运营里程轨道交通的碳排放强度.研究表明:(1)定员人公里碳排放因子(RPCF)和实际人公里碳排放因子(APCF)指标均能有效评估城市客运方式的碳排放强度,但2个指标之间具有明显、不可忽略的差异.(2)从RPCF和APCF的平均水平来看,城市公共交通相较私人交通均具有明显的低碳优势.RPCF均值由大到小排序为:汽油小汽车、纯电动小汽车、柴油公交车、天然气公交车、城市轨道交通、纯电动公交车,取值分别为40.69,21.26,14.86,11.63,8.81,5.28gCO_(2)/(人·km);APCF均值由大到小排序为:汽油小汽车、纯电动小汽车、城市轨道交通、柴油公交车、天然气公交车、纯电动公交车,取值分别为113.02,59.06,43.14,42.47,33.24,15.07gCO_(2)/(人·km).相较于RPCF,城市轨道交通APCF的低碳优势减弱.(3)总体水平来看,城市轨道交通、柴油公交车相较于纯电动小汽车不具有低碳优势,天然气公交车和纯电动公交车相较城市轨道交通具有明显低碳优势,纯电动公交车是最低碳的客运方式,汽油小汽车是最不低碳的客运方式.(4)相较于低运营里程轨道交通,目前高运营里程轨道交通发挥出了更大的低碳优势.运营里程为0~70,70~200,200~400,400~600,600~800km的轨道交通对应的APCF分别为86.03,57.43,51.71,34.11,33.41gCO_(2)/(人·km).

To compare the carbon emissions levels across various urban passenger transport modes,we proposed a comprehensive evaluation index and developed a detailed calculation model for urban passenger transport carbon emission intensity.Through the application of Kruskal-Wallis test and Bonferroni correction,we discerned significant variances in carbon emission intensities among different urban passenger transport modes.Additionally,the k-means clustering method was further employed to examine the carbon emission intensity across urban rail transit(URT)of different operational mileages.The findings revealed:(1)Both RPCF(Rated person-kilometer carbon emission factor)and APCF(Actual person-kilometer carbon emission factor)indicators were effectively to assess the carbon emission intensity of urban passenger transport modes,yet a significant and non-negligible difference between these two indicators was observed.(2)When average levels of RPCF and APCF were examined,urban public transport was shown to have a clear low-carbon advantage over private transport.The average values of RPCF were determined in descending order for gasoline cars,electric cars,diesel buses,natural gas buses,URT and electric buses,recorded as 40.69,21.26,14.86,11.63,8.81 and 5.28gCO_(2)/(person·km)respectively;whereas APCF averages were identified in descending order for gasoline cars,electric cars,URT,diesel buses,natural gas buses and electric buses,noted as 113.02,59.06,43.14,42.47,33.24 and 15.07gCO_(2)/(person·km).Compared to RPCF,the low-carbon advantage of URT's APCF was diminished.(3)URT and diesel buses were not observed to have a low-carbon advantage over electric cars.Natural gas buses and electric buses exhibited a significant low-carbon advantage compared to URT,with electric buses being identified as the most carbon-efficient mode and gasoline cars as the least.(4)URT with higher operational mileage was shown to have a greater low-carbon advantage compared to that with lower mileage.URT with operational distances of 0~70,70~200,200~400,400~600 and 600~800 km had their APCF measured as 86.03,57.43,51.71,34.11 and 33.41gCO_(2)/(person·km).