Assessing the added value of convection-permitting climate models in simulating flooding in southern Quebec watersheds

This project aims to answer the following question : Does the improved simulation of precipitation extremes with the new generation of regional climate models with 2.5 km resolution lead to an improvement in flooding simulations by a hydrological model in southern Quebec?

Project details

Scientific program

2020-2025 programming

Theme(s) and priority(s)

Extreme Events - Water Availability - Climate Science and Climate Services

Start and duration

December 2023 • March 2025

Project Status

In progress

Principal(s) investigator(s)

Philippe Lucas-Picher

UQAM

Richard Turcotte

DEH, MELCC

Context

A new version of the Canadian Regional Climate Model (CRCM6) has been under development for three years. This new version allows for long simulations at 2.5 km resolution. In this project, we will verify whether this new version of the CRCM improves the simulation of precipitation extremes in small watersheds in southern Quebec. In the future, it will be interesting to see whether this improvement in precipitation also improves the high water peaks simulated by a hydrological model.

Objective(s)

To determine whether the added value of the 6th version of the Canadian Regional Climate Model (CRCM6) at 2.5 km resolution leads to improvements in river flow simulation with hydrological models, particularly for flooding in southern Quebec watersheds
To determine whether climate change scenarios using the CRCM6 at 2.5 km provide new insights into flood patterns compared with those using CRCM6 scenarios at 12 km

Methodology

Compare the simulation of extreme precipitation by the MRCC6 at 2.5 km with that by the MRCC6 at 12 km.
Implement and calibrate the GR4H hydrological model (and Hydrotel as well, if time permits) on an hourly scale using meteorological data (temperature and precipitation) and observed flows in various basins in southern Quebec.
Produce hydrological simulations by forcing the hydrological model(s) with past and future scenarios from CRCM6 at 2.5 km and 12 km.
Compare the simulated flows with the observed flows using various hydrological indicators associated with flooding.

Expected results

We hope that high water peaks and floods will be better simulated using hourly weather data from CRCM6 at a 2.5 km spatial resolution. This is likely to improve future flood projections, especially for smaller watersheds not currently covered by the Hydroclimatic Atlas of Southern Québec published by the Ministère de l’Environnement, de la Lutte contre les Changements Climatiques, de la Faune et des Parcs (MELCCFP).