Author(s): Chen Liang; Kaihua Guo; Mingfu Guan

Linked Author(s): Kaihua GUO, Mingfu Guan

Keywords: Flood risk assessment; Metro systems; Shallow water equations; Urban flooding

Abstract: Urban flooding poses a significant threat to metro lines, making them vulnerable to sudden interruptions and risking the loss of lives. Therefore, to understand flood risk of a metro system becomes crucial from both academic and practical perspectives. Through a case study of the extreme flooding triggered by a record-breaking rainstorm on September 7, 2023, in Hong Kong, this study develops an approach for evaluating the flood risk of metro systems based on two-dimensional modelling of rainfall-induced flooding and its interaction with metro infrastructure. In this study, the hazard map of the metro system is quantified through detailed simulation of floodwater characteristics. The exposure map is determined by the floor area of each metro station, while the vulnerability map is based on the operational business of the metro system. This study quantifies the flood risk by multiplying the hazard, exposure, and vulnerability indexes. Subsequently, a comprehensive spatially and temporally explicit flood risk assessment of the metro system in Hong Kong is conducted by integrating the hazard, exposure, and vulnerability maps. The findings reveal the temporal sensitivity of flood risk in metro lines during extreme rainfall-induced flood events. These results provide valuable insights for implementing flood-proof measures on metro lines and enhancing the flood resilience of metro systems.

DOI: https://doi.org/10.64697/HIC2024_P191

Year: 2024