Impacts of Accessibility on Spatial Heterogeneity of Multimodal Transportation Carbon Emissions in an Urban Agglomeration
Under the double stress of the significant challenge posed by carbon emission reduction in the current transportation industry and the long-term plan for transportation development of China's urban agglomerations,improving the travel efficiency and simultaneously reducing carbon emission by improving accessibility is one of the key issues that need to be addressed urgently.This study proposed a method to estimate the carbon emission of intercity multimodal passenger transportation from the perspective of residents'travel using mobile phone signal data.Then,the impact of accessibility on the spatial heterogeneity of multimodal transportation carbon emissions was investigated using the gradient boosting decision tree(GBDT)model and the multi-scale geographically weighted regression(MGWR)model.The Guanzhong Plain urban agglomeration is taken as the study area.The results show that:the carbon emissions of the intercity road passenger are higher than railway,and distribution characteristics along transportation infrastructure lines.Accessibility has a positive marginal effect on the level of carbon emissions in the whole area.The MGWR can characterize the spatial heterogeneity and scale difference in the relationship between carbon emissions and accessibility indicators.Economic potential,betweenness centrality,and closeness centrality have significant positive spatial heterogeneity impacts on the intercity carbon emissions,but the scale of the effects varies.Carbon emissions of road passenger transportation are sensitive to betweenness centrality and closeness centrality,but the spatial impact of economic potential on carbon emissions is stable.The effect of increased rail travel accessibility on the central city is lower than that on the surrounding district and counties.