An approach to assessing tsunami risk to the global port network under rising sea levels
npj Natural Hazards volume 1, Article number: 38 (2024 ) Cite this article
Seaports are vulnerable to extreme sea level events. Beyond physical damage, any port inoperability affects trade flows in and out of the affected port and disrupts shipping routes connected to it, which then propagates throughout the port network. Here, we propose an approach to assessing tsunami risk to ports and the global port network. We leverage on the topological properties of the global liner shipping network and centrality measures to quantify the potential impacts of a Manila Trench earthquake-tsunami under both present and future sea levels. We find that a Manila Trench tsunami could potentially damage up to 11 ports at present-day conditions and 15 ports under rising sea levels. Port closure could exceed 200 days and cause greater disruption to shipping routes than historical tsunami events. We also find that sea level rise is likely to result in uneven changes in tsunami heights spatially and hence, uneven impacts on the global port network.
Seaports are vulnerable to extreme sea level events, such as coastal floods, storm waves and tsunamis1,2,3. Unlike coastal floods and storms which are mostly localised events, tsunami waves have a proven reach where a singular event can damage several ports at once, even those of thousands of kilometres away4. The 2004 Indian Ocean tsunami, for instance, damaged port facilities across the Indian Ocean including those in Indonesia, Thailand and Sri Lanka5. On the same note, the 2011 Great East Japan (Tohoku) earthquake-tsunami resulted in damage to 14 ports along the Tohoku Region in Japan, and a number of small craft harbours along the west coast of the United States4,5.
