The resurgence of landslides in the Hudson Bay area is of concern to northern communities. To understand the dynamics of the region’s clay soils, the Ministère de la Sécurité publique is collaborating with Ariane Locat, professor in the Faculty of Science and Engineering and coordinator of the Laboratoire d’études sur les risques naturels (LERN) at Université Laval.
The research project, which began in March 2024, follows four major landslides in 2021 and 2022. One of them occurred eight kilometers from the villages of Whapmagoostui and Kuujjuarapik, a territory occupied and traveled by the communities for their traditional hunting and fishing activities.
"They say they are afraid to navigate in the mouth of the river because there is still debris from the landslide. Some trees are still moving. There are risks associated with traffic," reports Ariane Locat, whose team is collaborating with two professors from Université Laval’s Faculty of Forestry, Geography and Geomatics, Pascale Roy-Léveillée and Patrick Lajeunesse.
With a view to prevention and adaptation, the Ministère de la Sécurité publique has granted nearly $858,000 to the research team through the Quebec government’s Loss Prevention Framework. The project is also being carried out in partnership with the Ministère des Transports et de la Mobilité durable.
"When government engineers have to respond to emergency situations, they are faced with a lack of documentation on the soils in the area. Any knowledge added by our project will be useful to them, especially for mapping the area," says Professor Locat.
Sampling in a remote area
To study past landslides, the researcher and her team travel by helicopter to the field to collect soil samples by shovel and in tubes, which will be brought back to the laboratory on campus for analysis. "We want to know under what conditions they occurred, in what types of soil. We also want to determine whether the upsurge is linked to climate change, as northern regions are affected more rapidly than in the south."
Soil properties can then be compared with those of soils in the St. Lawrence Valley. "The soils don’t have the same geological history, but we can draw a lot of parallels."
For example, Hudson Bay soils seem to be more susceptible to reworking, meaning that if there’s an earthquake, bad weather or erosion, a slide can be initiated and the soils can lose their strength and act like a viscous liquid. "We find this type of slide in the south too, but the scale of magnitude is much greater there," reports Ariane Locat. It’s intriguing. We want to understand why."
Part of the study will also take place in the James Bay area, further south. This area is more accessible by road," says Professor Locat. This will enable us to carry out more in-depth research using drills, since we don’t have any machinery in Hudson Bay. We will then be able to extrapolate our results as both territories are in the same sedimentary basin."
Collaboration with the Centre d’études nordiques is essential for conducting research in Nunavik. "It helps us with accommodation, food and transportation. It gives us access to a research station and acts as a bridge with the communities. I’m impressed by this network," says Ariane Locat.
Knowledge transfer is an important aspect of the project, whether with engineers or local communities directly concerned by the landslide issue.
