Hinterland Evolution Of Container Ports In The Yangtze River Delta ——Based On Field Model And Shipping Network

Under the background of regional economic integration and containerization,the management and expansion of port hinterland become the core to guarantee the competitiveness of modern ports.At present,the Yangtze River Delta（YRD）port group has become the most densely distributed port group with the largest throughput in China,which is preliminarily qualified for the construction of world-class port group.From the perspective of field model and shipping network connection,the direct and indirect hinterland evolution of major container ports in the YRD is crucial to optimize the strategic design,infrastructure layout and policy making of the ports in the YRD.This paper takes the top 10 ports in the YRD in terms of container throughput in 2019 as the research object,and takes 2006,2012 and 2019 as the time sections.Firstly,according to the port attribute data and traffic accessibility data,this paper uses the field model to quantitatively divide the direct hinterland of the ports and analyze the evolution characteristics.Secondly,the hierarchical structure of the port system is divided according to centrality.The hub-spoke network structure is generated by combining the port connection strength,so as to clarify the hub ports and branch ports in the YRD container port system.Thirdly,if the field strength of hub port in direct hinterland of its branch port is greater than the average field strength of all ports,the direct hinterland of the branch port is divided into the indirect hinterland of the hub port.Then,the evolution characteristics are analyzed,and the impact of market forces and administrative forces on port hinterland pattern is explored.The results show that:（1）The direct hinterland of ports in the YRD was obviously different.The number of direct hinterlands of Nanjing port,Wuhu port,Wenzhou port and Lianyungang port remained upstream.The direct hinterland of Ningbo Zhoushan and Shanghai port had obvious ebb and flow.The number of direct hinterlands of Jiaxing port,Wuxi port,Suzhou port and Nantong port were in the downstream.Shanghai port and Ningbo Zhoushan port had less direct hinterland,because the competition of ports in the east of the YRD was fierce,and the competition between seaports had shifted to indirect hinterlands.（2）The connection between Shanghai port and inland ports along the Yangtze River had been strengthened year by year,and the network organization and control ability of liner feeder had been strengthened.However,Ningbo Zhoushan port lacked the liner feeder in the Yangtze River and preferred to strengthen the route connection with inland ports in Zhejiang Province.The number and density of routes in Suzhou port had surpassed that in Nanjing port,and Suzhou port had become the hub inland port in the Yangtze River.The routes of Nanjing port,Nantong port and Wuxi port had high connection intensity.The connection intensity of Lianyungang port and Wuhu port were low.（3）The structure of hub-spoke network of container ports in the YRD was relatively stable.In 2006,the only branch port of Shanghai port was Lianyungang port.Wenzhou port was the only branch port of Ningbo Zhoushan port.Nantong port,Wuxi port and Jiaxing port were branch ports of Suzhou Port.Wuhu port was a branch port of Nanjing port.In 2012,Jiaxing port became a branch port of Ningbo Zhoushan Port.In 2019,Shanghai port added Nanjing port and Wuhu port as branch ports.（4）The indirect hinterland of Shanghai port increased the most,and the indirect hinterland showed a trend of westward expansion.The indirect hinterland of Ningbo Zhoushan port continued to expand westward and southward.The indirect hinterland of Suzhou port was concentrated inwards to the southern and central areas of Jiangsu.Nanjing port became the branch port of Shanghai Port,so the indirect hinterland shrank.（5）The evolution of port hinterland showed three trends of shrinking,expanding and stabilizing.The hinterland evolution of Shanghai and Ningbo Zhoushan port were the most obvious,with the hinterland range constantly expanding to the southwest.The hinterland of Wuhu port shrank first and then expanded.The hinterland of Suzhou port shrank inward.The hinterland of Nanjing port shrank northward.The hinterland of Jiaxing port shrank northeast.The hinterland of Lianyungang,Wuxi,Nantong and Wenzhou port tended to be stable.（6）The hinterland development strategy of Shanghai port relied more on market tools and the support of the central government to expand the indirect hinterland along the Yangtze River.Ningbo Zhoushan Port tended to extend the hinterland scope to Zhejiang province through the administrative power and the cooperation with the dry port.