Clarence Gagnon

NH Natural Hazards

The 2025 Outstanding Student and PhD candidate Presentation (OSPP) Award is awarded to Clarence Gagnon for the poster/PICO entitled:

The role of extratropical cyclones in flooding in Quebec, Canada, from 1991 to 2020 (Gagnon, C.; Nadeau, D. F.; Di Luca, A.; Anctil, F.; Brault, B.; Hamon, R.; Roy, N.; Bourgault, M.-A.)

Click here to download the poster/PICO file.

Clarence Gagnon is a second year Master’s student in the Department of Civil and Water Engineering at Université Laval in Quebec, Canada, where she is supervised by Prof. Daniel F. Nadeau. She is also co-supervised by Prof. Alejandro Di Luca in the Department of Earth and Atmospheric Sciences at UQAM University in Montreal.

The aim of her research was to quantify the role of extratropical cyclones (ETCs) in flooding in the Canadian province of Quebec between 1991 and 2020, using governmental financial aid data, cyclone tracks, and precipitation data.

At the EGU conference, she presented her main findings on the 498 flood events analysed – namely, that the ETCs which contributed to flooding in the province had longer lifetimes and tended to originate from the Central US. These cyclones also tracked closer to the study area than typical storms over the domain. The contribution of ETCs to flooding (the percentage of rainfall associated with the cyclones) varied seasonally, with more extreme (both high and low) values occurring in summer. 

Thanks to her research, 30 years of governmental financial aid data has been valorised through this 498-flood events case study, which is the first of its kind in the study area. This has advanced our understanding of the contribution of ETCs to flooding. Specifically, she has identified common cyclone characteristics that make them more likely to cause flooding, which could help with flood preparedness.