Brock University study documents climate change impacts in Old Crow, Yukon

Caleb Charlie remembers a time when Lake Zelma was a big, beautiful body of water with nearby family camps, teeming with life and cultural significance, in the Yukon area of Old Crow Flats.

Since then, it drained and dramatically altered the landscape. The photographer recalls how much the lake collapsed after it breached a part of the shoreline that had thawed.

“You obviously want the land to flourish and be as beautiful as it is and stay that way and so it hits a nerve when you think that things are only getting worse,” says Charlie, who is with the Vuntut Gwitchin government’s Natural Resources Department.

Charlie and other members of Vuntut Gwitchin First Nation are working with Brock Associate Professor Kevin Turner on long-running research documenting the impacts of climate change in Old Crow Flats, a wetland north of the Arctic circle and south of the Beaufort Sea.

One of their recent projects, titled “The Sky is the Limit for Community Monitoring of Climate Change Impacts in Old Crow, Yukon,” is being funded by a Brock University Indigenous Research Grant.

“My hope is that this project will be a useful stepping-stone for developing a long-term, community-driven landscape change monitoring program,” says Turner, who is based in the Department of Geography and Tourism Studies and cross-appointed with the Department of Earth Sciences.

Old Crow Flats is one of many sites worldwide on the Ramsar List of Wetlands of International Importance. The area spans the northern Boreal to tundra transition zone and is noted for its more than 8,000 freshwater lakes and ponds, peatlands, sedge marshes, tundra and spruce forest stands. It hosts abundant wildlife including the porcupine caribou herd and hundreds of thousands of waterfowl.

An aerial view of a thaw slump in Old Crow Flats, Yukon.An aerial view of a thaw slump that has grown over time in Old Crow Flats, Yukon. The map of the slump was derived from over 200 overlapping photographs taken by Caleb Charlie.
Landscape features of Old Crow Flats are kept stable by permafrost, which is ground that has been frozen for two or more years. But warmer temperatures, increased rainfall and a shorter winter period can cause permafrost to thaw.

When that happens, the land become unstable in low-lying areas or in places where there are steep slopes or water bodies near to each other.

Thawing permafrost along steep slopes can cause landslides called thaw slumps, which start off as landslides but can continue to expand for years, transporting large amounts of soil and other debris into lakes and rivers.

Water bodies, on the other hand, can simply drain out, says Turner. “While these are natural features within this type of dynamic landscape, the frequency of these processes is on the rise.”

Turner has been studying Old Crow’s hydrology, water chemistry and land changes for almost two decades. In 2016 he and his lab partnered with the Vuntut Gwitchin Government to study the growth of a large thaw slump along the Old Crow River in Crow Flats.

Charlie joined the research team in 2019 as a field assistant to help document these changes. Soon after he became an avid photographer, videographer and drone pilot.

With their 2022 Indigenous Research Grant, Charlie has continued to work with Turner on processing the drone images that they acquired during the past two summers at the thaw slump and a newly drained lake basin.

Turner designed a workshop for Charlie and other participants at Brock to demonstrate the photogrammetry process, which involves making precise measurements of three-dimensional objects and terrain features from overlapping two-dimensional photographs.

“Imagine 200 photographs over a landslide and the photographs are all overlapping,” says Turner. “We stitched them together using the common features within them and ground location information to create to produce high-quality mapping products. Repeat surveys allow us to monitor the rates and magnitude at which these features change.”

Turner says he is excited by how photogrammetry can complement Vuntut Gwitchin First Nation’s “very strong oral history” and traditional knowledge of the land.

He says he hopes the team’s efforts demonstrate how the First Nation can integrate this type of drone photography and 3D mapping technology into a regular monitoring program that follows up on sightings by community residents, including thaw slumps in new locations.

“Drones are ideal in this terrain because you’ve got bluffs along the river that can be upwards of 40 meters high, so you can’t really get up there safely,” he says. “Thaw slumps and other erosional disturbances present hazards and disruptions to the community.”

“The images and the research really help complement our ability to key an eye on the land,” says Charlie.