Abair et al. (2025) Strengthening coastal flood forecasting through event-based data capitalization: a case study from the December 2022 storm surge in Québec City

Identification

• Journal: Natural Hazards
• Year: 2025
• Date: 2025-12-26
• Authors: Sara Abair, Abdelkader Hammouti, Juzer Noman, Sylvie Daniel, Damien Pham Van Bang
• DOI: 10.1007/s11069-025-07780-5

Research Groups

• Centre Eau-Terre-Environnement, Institut National de la Recherche Scientifique, Université du Québec, Québec, Canada
• Université du Québec, École de Technologie Supérieur, Montréal, Canada
• Université Laval, Québec, Canada

Short Summary

This research validates a 2D hydrodynamic model for coastal flood risk management in Québec City, using it to analyze the December 23rd, 2022, storm surge event and demonstrating its ability to accurately reproduce spatio-temporal water levels and velocities in urban areas, influenced by wind and urban channelization.

Objective

• To validate a 2D hydrodynamic model of the Saint-Lawrence Fluvial Estuary (SLFE) for coastal flooding risk management in Québec City.
• To use the validated model to analyze the flood event of December 23rd, 2022, in Québec City.

Study Configuration

• Spatial Scale: The study area covers the transitional zone of the Saint-Lawrence Fluvial Estuary, 120 km long from Baie Saint-Paul to Neuville, with a specific focus on the urban area of Québec City. The computational grid features variable resolution from 2 meters in urbanized areas (including buildings) to 250 meters in the broader SLFE, with 50 meters resolution near Québec City and Île d'Orléans.
• Temporal Scale: The primary event analyzed is the coastal flooding on December 23rd, 2022, caused by the Elliott winter storm. Model validation was performed using data from two periods in June 2009 (12–15 June for neap tide and 21–24 June for spring tide). The hydrodynamic model uses a time step of 5 seconds.

Methodology and Data

• Models used:
  • TELEMAC-MASCARET modeling system (specifically Telemac2D, a 2D depth-integrated version using an unstructured finite element method) for hydrodynamic simulations.
  • Empirical Bayesian Kriging (EBK) for interpolation and fusion of multisource topo-bathymetric data.
  • Flather’s formula for wind stresses and Manning’s formula for bottom friction.
  • k-epsilon turbulent model for effective diffusion.
• Data sources:
  • Topography: High-resolution LIDAR data (4 points/m², 50 cm horizontal accuracy, 15 cm vertical accuracy) from various governmental and municipal sources (e.g., CMQuebec 2019 survey).
  • Bathymetry: Multisource data compilation from Canadian Hydrographic Services (NONNA data), municipal partners (CMQuebec, City of Quebec), Quebec Ministry of Transport, and recent surveys (RQM-OSIRISQ project 2020–2022).
  • Meteorological: Wind speed, direction, and atmospheric pressure data from Jean Lesage International Airport (Environment and Climate Change Canada) for the December 2022 event.
  • Water Level Observations: Tide gauge data from Saint-Joseph-de-la-Rive and Neuville for boundary conditions and model validation.
  • Flood Event Observations (December 2022): In-situ water level measurements at 47 points by Québec City municipal agents and complementary spatio-temporal information from social media videos and press photographic data.
  • Validation Data (June 2009): Water level observations at Estuaire Saint-Charles, Saint-François, and Rocher-Neptune, and flow discharge measurements at Quebec, Beauport, and Lauzon.

Main Results

• The developed topo-bathymetric digital elevation model (TBDEM), created through multisource data fusion and EBK interpolation, achieved an estimated error of 0.6 meters in shallow water zones and 0.25 meters in urban areas.
• The Telemac2D model, calibrated with a 5-second time step, accurately reproduced observed water levels and flow discharges during both neap and spring tides in June 2009, demonstrating its reliability.
• During the December 23rd, 2022, Elliott storm surge, the model successfully simulated the spatio-temporal distribution of water levels and velocities in Québec City, showing good agreement with municipal and social media observations.
• Wind forcing significantly influences water levels in the urban area and affects the timing of flooding events, with both homogeneous and non-homogeneous wind fields showing minor amplitude changes but modulating flood timing.
• Urban configuration, particularly Dalhousie Street, acts as a main channel, leading to flow channelization with velocities reaching up to 1 meter per second at point OBS25, significantly higher than in other areas.
• Flood curves in the urban area exhibit asymmetry, with drainage durations being notably slower than submersion, and a distinct phase shift (up to 1.5 hours) between the tidal signal and the urban flow.
• The model indicates that some urban areas may remain wet during ebb tide due to local topographic depressions.

Contributions

• Introduces a robust methodological approach for integrating and fusing multisource, multi-temporal high-resolution topographic and bathymetric data to create a consistent TBDEM for complex estuarine and urban environments.
• Validates a 2D hydrodynamic model (Telemac2D) for coastal flood forecasting in Québec City, demonstrating its capability to accurately simulate real-world storm surge events and provide spatio-temporal distributions of water depth and velocity.
• Proposes a modular framework that allows extending a fully hydraulic model to urban areas without extensive re-meshing or re-calibration, facilitating rapid adaptation for urban flood simulations and future urban planning updates.
• Highlights the critical value of capitalizing on event-based multisource data (municipal measurements, press photos, social media) for validating flood models in data-scarce extreme events.
• Provides crucial quantitative information on water depth and velocity in a densely populated urban zone during a storm surge, which is essential for classifying flood hazard levels and defining optimal crisis management plans.
• Investigates and quantifies the influence of wind forcing and urban channelization on flood propagation dynamics, revealing their significant impact on flood timing and localized flow characteristics.

Funding

• Réseau Québec Maritime (Odyssée Saint-Laurent program, Grant No. 2017-2022-39557)
• REFORMAR
• Compute Canada (project ESPRIL, No. 4516)
• NSERC-Discovery, Canada program (RGPIN-2018-0677)

Citation

@article{Abair2025Strengthening,
  author = {Abair, Sara and Hammouti, Abdelkader and Noman, Juzer and Daniel, Sylvie and Bang, Damien Pham Van},
  title = {Strengthening coastal flood forecasting through event-based data capitalization: a case study from the December 2022 storm surge in Québec City},
  journal = {Natural Hazards},
  year = {2025},
  doi = {10.1007/s11069-025-07780-5},
  url = {https://doi.org/10.1007/s11069-025-07780-5}
}