Radiation Range Measurement And Policy Impact Analysis Of Sea-Rail Intermodal Stations In The Hinterland Of Port

China’s port container throughput ranks first in the world,but the contradiction of imbalance in the structure of port collection and distribution mode is prominent,especially the low proportion of railroad collection and distribution,which is not conducive to the low-carbon transformation of ports.In the context of the "double carbon" strategic objectives,promoting the development of sea-rail intermodal transport and optimizing the structure of port transportation is an inevitable requirement for the construction of sustainable ports.To this end,departments at all levels have come out of the sea-rail intermodal transport guidance policy to promote the orderly transfer of road transportation to the railroad.The sea-rail intermodal transport stations in the hinterland as a key node connecting the inland hinterland and coastal ports,and the clear scope of radiation of the stations helps railway transport enterprises to carry out targeted marketing of sea-rail intermodal transport.Quantitative assessment of the impact of the guidance policy on the radiation range of railroad stations and the competitiveness of sea-rail intermodal transport is conducive to the optimization and adjustment of the sea-rail intermodal transport guidance policy.Based on this,this paper focuses on the following two topics: "Measuring the radiation range of sea-rail intermodal stations" and "Impact assessment of sea-rail intermodal guiding policies".Firstly,based on the systematic elaboration of the existing related research works and the summary of the existing research deficiencies,a method of analyzing the radiation range of sea-rail intermodal transport stations integrating GIS spatial network analysis and generalized cost theory is proposed by considering the actual network structure of road and railway,and through spatial simulation sampling.Taking Xiamen Port and Fuzhou Port,two major container ports in Fujian Province as examples,focusing on the two ports have opened the hinterland railroad station of sea-rail intermodal transport trains to carry out research.Based on the hierarchical system sampling method,the demand point is determined by GIS;For the sampling points,the matrix of road and rail distance and drayage distance is obtained by OD cost matrix analysis;According to the generalized cost theory,the generalized costs of each sampling point to the port by road and railroads are measured separately,and the distribution of demand points for railroads to the port is determined based on the principle of minimizing generalized costs;And the radiation range of each station and the competitiveness of sea-rail intermodal transport are calculated accordingly.The results show that in the study area,the sea-rail intermodal competitiveness of Fuzhou port is significantly higher than that of Xiamen port,which is as follows: In terms of sea-rail intermodal share,the sea-rail intermodal share of Fuzhou port(7.85%)is about 2.74 times higher than that of Xiamen port(2.87%).In terms of the radiation range of the intermodal stations,the radiation range of the hinterland stations in Fujian Province of both ports is about 15 km,but the radiation range of the railroad stations in Fuzhou Port(about15-45km)is significantly larger than that of Xiamen Port(about 15-30km)in the hinterland outside the province.Secondly,around the generalized cost of railroad arrival at the hinterland demand points of the two cases,the percentage structure of each generalized cost element such as rail tariff rate,freight train travel speed,drayage rate and frequency of liner departures is analyzed.And the elasticity analysis of sea-rail intermodal transport sharing rate for these elements,are used to clarify the key factors affecting the competitiveness of sea-rail intermodal transport.Finally,taking the financial subsidy policy and the internalization of carbon emission cost as examples,which is to analyze the impact of the two policies on the competitiveness of sea-rail transport.The results show that reducing the railroad "door to port" transport costs is the key to enhance the competitiveness of sea-rail intermodal transport.And improving the time efficiency of railroad "door-to-port" transportation,especially shortening the waiting time at the yard,is important to improve the competitiveness of sea-rail transport.In addition,financial subsidies can effectively promote the development of Xiamen port’s sea-rail intermodal transport,which shows that after the implementation of financial subsidies,the radiation range of each sea-rail intermodal transport station in Xiamen port has increased significantly,and the sharing rate of sea-rail intermodal transport in the research area has increased by about 4.33%.However,about45.04% of the incremental sea-rail intermodal transport in Xiamen port is transferred by the railroad source of Fuzhou port,and the problem of vicious competition of railroad sources in the hinterland between neighboring ports is significant.After internalizing the cost of carbon emissions,the radiation range of each sea-rail transport station at Xiamen port has increased within 10 km,and the sea-rail share of the port of Xiamen in the research area increased by about1.28%.And the longer the railroad distance,the more significant the effect of sea-rail share improvement.