国家中心城市交通碳排放效率的空间网络结构及动因研究

Research on spatial network structure and influencing factors of transportation carbon emission efficiency in national central cities in China

为科学把握城市交通碳排放效率的空间网络结构,实现交通运输业可持续发展,基于2011—2020年我国9个国家中心城市交通碳排放数据,构建考虑非期望产出的全局超效率SBM模型(GB-US-Super-SBM模型)并测算交通碳排放效率,利用修改的引力模型建立空间关联网络,在此基础上应用社会网络分析方法厘清交通碳排放效率空间网络结构及其动因。结果表明:1)研究期内,9个国家中心城市交通碳排放效率整体水平不高,城市间存在较大差距。2)国家中心城市交通碳排放效率的空间关联呈现网络结构形态,并逐渐形成了天津、西安、郑州等多个网络中心;空间网络关联性以2017年为节点呈现先增强后减弱的趋势;天津、西安、郑州等城市发挥着“桥梁”和“中介”作用,对空间网络的形成发挥了重要作用。3)经济发展水平差异、城镇化水平差异、节能技术水平差异和空间邻接关系等因素在交通碳排放效率的空间网络结构中发挥显著作用,其中空间邻接关系和经济发展水平差异的影响最显著。

In order to scientifically grasp the spatial network structure of carbon emission efficiency in urban transportation and achieve sustainable development in the transportation industry,based on the data of nine national central cities in China from 2011 to 2020,a global super efficiency SBM model(GB-US-Super-SBM model)considering unexpected output was constructed to assess the transportation carbon emission efficiency;the revised spatial gravity model was used to construct the spatial correlation network and,based on this,the social network analysis method was applied to reveal the spatial network structure of transportation carbon emission efficiency and the influencing factors.The results showed that:(1)During the entire study duration,the overall transportation carbon emission efficiency of nine national central cities was relatively low,and there were considerable gaps among the cities.(2)The spatial correlation of transportation carbon emission efficiency in national central cities presented a network structure,gradually forming multiple network centers such as Tianjin,Xi'an and Zhengzhou;the spatial network of transportation carbon emission efficiency shows a trend of first strengthening and then weakening with 2017 as the node;cities such as Tianjin,Xi'an and Zhengzhou served as"bridges"and"intermediaries",playing a crucial role in the shaping of the spatial network.(3)Variations in economic development,urbanization,energysaving technology and spatial proximity significantly influenced the spatial configuration of carbon emission efficiency in transportation.Among these factors,spatial proximity and differences in the level of economic development exerted the most substantial impact.