The final publication is available at Springer via http://dx.doi.org/10.1007/s11069-020-03860-wMetro systems perform a significant function for millions of ridership worldwide as urban passengers rely on a secure, reliable, and accessible underground transportation way for their regular conveyance. However, hazards can restrict normal metro service and plans to develop or improve metro systems set aside some way to cope with these hazards. This paper presents a summary of the potential hazards to underground transportation systems worldwide, identifying a knowledge gap on the understanding of water-related impacts on metro networks. This is due to the frequency and scope of geotechnical and air quality hazards, which exceed in extreme magnitude the extreme precipitation events that can influence underground transportation systems. Thus, we emphasize the importance of studying the water-related hazards in metro systems to fill the gaps in this topic.Peer ReviewedPostprint (author's final draft
