The Complex Properties of Chinese Ship-Transport Networks

Abstract

Transportation systems are of great importance to the development of a country and are important indicators of its economic growth With 30 per cent of Chinese trade carried by sea and with 90 percent of world trade carried by sea, the global network of merchant ships provides one of the most important modes of transportation. Here, we use information about the itineraries of 187260 ships during the year 2010 to construct a network of links between ports. The network has several features that set it apart from other transportation networks are shown. In particular, most ships can be classified into three categories: bulk dry carriers, container ships and oil &LNG gas tankers. These three categories do not only differ in the ships’ physical characteristics, but also in their mobility patterns and networks. Container ships follow regularly repeating paths whereas bulk dry carriers and oil tankers move less predictably between ports. The network of all ship movements possesses a heavy-tailed distribution for the connectivity of ports and for the loads transported on the links with systematic differences between ship types. The data analyzed in this paper improve current assumptions based on gravity models of ship movements, an important step towards understanding patterns of global trade. We also study the traffic flow of Chinese ship-transport networks (CSTN) based on the weighted network representation, and demonstrate the weight distribution can be described by power-law or exponential function depending on the assumed definition of network topology. Other features related to Chinese ship-transport networks (CSTN) are also investigated.