Citation

Kouroshnejad K, Sushama L, Sandanayake H, Cooke R, Ziya O. Saf. Extrem. Environ. 2023; 5(3): 161-176.

Copyright

(Copyright © 2023, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s42797-023-00077-5

PMID

unavailable

Abstract

Flash flooding caused by short-duration high-intensity precipitation events is a major cause of weather-related traffic disruptions in summer, especially in urban areas with impermeable surfaces such as pavements and buildings. As the weather becomes warmer, the frequency of flash floods is expected to increase, which can further exacerbate traffic disruptions. This study investigates flash flood-traffic interactions for current and future climates in Ottawa, Canada, by integrating ultra-high-resolution (4 km) regional climate model (RCM) simulations with inundation modelling using PCSWMM and transport network modelling. This study considers flash floods associated with 100-year return levels of short-duration (1-h, 3-h, and 5-h) precipitation events, with projected changes estimated using two approaches based on the RCM simulation results and temperature scaling method. Quantitative validation of the RCM-simulated precipitation results and their spatial variability, against gridded and station observations, along with qualitative validation of the hydrodynamic model simulated flash flood depths, confirm the suitability of the models in analyzing flash flood-related traffic disruptions. The results show that the 100-year return levels of 1-h, 3-h, and 5-h precipitation events are projected to increase by 16-55% for the future 2081-2100 period compared to the 1991-2020 period, leading to increases in blocked roads and traffic disruptions in the 57-77% range and delays in the 28,000-38,000 cumulative hours range. By identifying road links susceptible to flash flood-related traffic delays, this study provides a practical framework for guiding the development of adaptation measures to increase resilience in the urban transportation network.

Language: en

Keywords

Climate change; Flash floods; Inundation modelling; Traffic disruption; Transport network modelling; Ultra-high-resolution regional climate modelling