In this article we want to talk about revisits the classical issue of port city relationships by applying for the first time network analytical methods. This research thus contributes to question the ineluctable separation between ports and cities which dominated the literature. Main results show that although the largest cities have witnessed diminishing importance in world traffic. Read below about the changing influence of city-systems on global shipping networks.
The changing influence of city-systems on global shipping networks: Introduction
Economic geography and regional science have persistently ignored maritime transport in their conceptualization. Port cities and maritime networks are at center stage in a world. Urban development was often considered within land-based systems, such as the central place theory and the New Economic Geography. A review of port geography papers published since the 1950s showed that human geography gradually lost interest in ports and maritime transport. Maritime functions are no longer considered by researchers who establish rankings of world cities competing for the control and domination of the world economy. Very few attempts were made to fill such a gap, such as the measurement of cities’ global accessibility combining multiple layers of which maritime flows. These studies remain highly static and cannot account for the evolution of the linkages between maritime transport and urban development.
Maritime network construction
The changing influence of city-systems on global shipping networks: For the purposes of this research, it was decided to extract from paper sources one publication every 5 years. The difficult readability of the printed original documents could not yet allow for the extraction of all information. The resulting tables were merged into one single maritime database. In the network, ports are considered as nodes, and flows between them as links, to allow the calculation of standard network measures originating from graph theory. Degree centrality is the number of adjacent neighbor nodes connected to node I as in formula. This coefficient is low at ports being bridges or hubs in the network, i.e. which neighbors are poorly connected with each other. At the level of urban areas, such measures can reveal to what extent is maritime centrality of different kinds influenced by the urban weight of port nodes.
Ports and urban spatial structures
The changing influence of city-systems on global shipping networks: The urban area level is the agglomeration or urban morphological area, with two possibilities. Each port or terminal was associated to the nearest urban center taking into account urbanization patterns, physical proximity, road accessibility, and urban system layout. Sometimes it had been necessary to verify the likely geographic extent of port hinterlands by consulting a wide variety of historical documents. This method is a necessary simplification of reality to allow discussing the distribution of flows in relation to the size and dimension of the places of shipment.
The changing influence of city-systems on maritime flows
The changing influence of city-systems on global shipping networks: The two larger quintiles Q6 and Q5 together concentrated nearly 80 % of the total maritime traffic handled by all urban areas in 1950. This noticeable drop recalls the aforementioned preliminary results as part of world traffic tended to shift to smaller cities over the period. The average demographic size of quintiles marks contrasted evolutions. Early phases of port system development showed a rather linear trend by which one dominant port accumulated traffic at the expense of its neighbors through a path-dependent process.