About 90% of maritime trade takes place in port cities and offshore network. Major cities of the world are still in many ways maritime cities. Port cities have also been vital centers of successive world systems throughout history from Tyr and Sidon in the Phoenician world to New York and Shanghai nowadays. Few to date have examined the role of cities in controlling and dominating the global economy. Researchers have made very little effort to fill such a gap. Also, these studies remain highly static and cannot account for the evolution of the linkages between maritime transport and urban development.
Maritime network construction
Of all the marine data, we have the only Lloyd’s list. It records the global distribution of sea currents separately over time. The Lloyd’s Shipping Index had been published daily or weekly since 1880 on a regular basis since the late nineteenth century. It gave us information about the ships and their latest departure between ports.
In this study, we obtain the first confirmation of urban impacts on maritime traffic and global shipping. Results were striking as the largest cities always concentrated the highest traffic share all over the period. The two larger quantiles Q6 and Q5 together concentrated nearly 80 % of the total maritime traffic in 1950. Also their combined share was still around 70 % in 1990. In other words, larger cities keep dominating global maritime flows. But they have been gradually challenged by smaller ones at the bottom of the urban hierarchy. You can see the tables and details in here.
At the level of individual urban areas, we calculated the Pearson correlation between the number of inhabitants and the number of vessel calls. The result was a sharp decline in the solidarity between the city and the port. Another result we got was the distance between cities. We provided some explanations for these results. One possible explanation is that the smallest cities are connected to the largest cities through long-term trade. As a result, they artificially flatten their geographical dominance. This seems to be a reasonable explanation. Because the average distance does not increase much for Q1 in the late period, contrary to its traffic share.
This research constitutes the first analysis of global shipping networks in relation to urban development. The results show that marine networks are space networks. The spatial distribution also strongly depends on the characteristics of the port.
Overall, we need more research to better understand urban and sea freight interdependence. It would also be better if we had urban and marine data over a longer period of time. The data show that road transport is increasing. The purpose of this study was to show the importance of cities and sea freight. The introduction of sea freight is very important in urban policies. Because it reduces congestion and the environmental effects of road freight.
Likewise, governments and ministries should pay more attention to sea freight in their policies.
Port cities have played a vital role in successive world systems throughout history and are still centers of maritime trade. About 90% of maritime trade takes place in port cities and offshore networks.
Using data from Lloyd’s list, researchers found that larger cities continue to dominate maritime flows, but smaller cities at the bottom of the urban hierarchy are gradually challenging their dominance. However, there was a decline in the correlation between the number of inhabitants and vessel calls, suggesting a decrease in solidarity between cities and ports.
Sea freight reduces congestion and the environmental effects of road freight, making it an important consideration for governments and ministries.
This research highlights the need for further study into the evolving relationship between cities and global shipping networks. The results suggest a complex interdependence between urban development and maritime traffic, with more research needed to better understand this dynamic.