An approach to assessing tsunami risk to the global port network under rising sea levels

Abstract

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.