Multi-hazard exposure of cities and implications for urban infrastructure

Abstract

In a disaster, people living in cities can face interruptions to water supply, electricity supply, transport, and other services, sometimes with severe consequences. In many cities, interruptions can be caused by various hazards (e.g. floods, earthquakes, landslides). Therefore, infrastructure services need to be made resilient not just to one hazard, but to the multiple hazards that could affect them. Yet hazards are often dealt with by different people or institutions, which limits how much we know about exposure to multiple hazards. In this study we combined global datasets for five hazards (river and coastal flood, earthquakes, storms, and landslides), and found that many cities, particularly in North America and Asia, are exposed to two or more of the hazards. Then we proposed a way of measuring the consequences on service of two hazards occurring together, using a hypothetical scenario (an earthquake and storm happen in a city within the same week and affecting the supply of water by damaging underground pipes and pumping stations). The results show that there could be up to 50% more disruption when the earthquake and storm happen within a day of each other, compared to if the same two events had happening separately. Finally, we explored how we can analyse disruption from combined hazards in an actual city given limited data availability, using the flood-prone city of Jingdezhen in China as a case study (we looked at road transport disruption under combined river flooding and debris flows). The results show potential for valuable insights even with limited data availability. Overall, we revealed limitations in a single hazard approach to infrastructure resilience and suggest how by combining existing data and methods for single hazards we can provide a valuable understanding of multi-hazard impacts to infrastructure services.

Date of Award	21 Jan 2021
Original language	English
Awarding Institution	University of Bristol
Supervisor	Dawei Han (Supervisor) & Alan R Champneys (Supervisor)