New interactive maps from a British Columbia-based tech company could help further the understanding of connections between last year’s wildfires and the devastating floods that followed in November.
British Columbia’s 2021 wildfires were the third-worst in terms of area burned, but saw several massive fires burning in close proximity to populated areas along with virtual complete destruction of the community of Lytton.
The flooding and landslides, which followed a series of powerful atmospheric rivers, caused major damage to multiple key highways, destroyed numerous homes and forced evacuations in Merritt, Abbotsford and several other communities.
The first map, which can be viewed here, walks users through some of B.C.’s most destructive fires and their aftermath.
The second map, which can be viewed here, places those fires in the context of some of the most destructive flooding.
The tool is the creation of Sparkgeo, a geospatial consulting company that pulls together information from sources like satellite imaging or GPS technology to visualize or analyze data.
“We’re trying to look at geographic chains of events and the chain of events that we saw happening in our backyard last year was this linkage between what we felt were the heat dome into wildfires, atmospheric rivers, landslides, (and) flooding events,” CEO Will Cadell explained.
“This is a good geographic story, and we felt that we were kind of uniquely positioned to start telling that story and to help people understand how how landscapes are changing and our climates are changing and how these things are colliding.”
To create the maps, the team pulled together satellite imagery from NASA’s fire Information Resource Management System (FIRMS), and the European Space Agency’s Sentinel-2 Satellite constellation, along with photos from the B.C. Ministry of Transport and Infrastructure.
Researchers like John Clague, an Earth Sciences emeritus professor at Simon Fraser University, have pointed to ways wildfires can make a landscape more vulnerable to flooding.
Clague said fires can destroy overhead canopy that helps slow the flow of water during rain events and the creation of “hydrophobic” water-repellant crusts in fire zones that allow heavy rain to shoot quickly down slopes.
Wildfires can also lead to soil erosion and instability, he said, as well as create debris that becomes destructive when swept up in floods.
“Now you wouldn’t normally think that fire and flooding would be linked, but it is in fact been demonstrated in other areas in the western U.S., for example, that wildfires can be followed by debris flows, erosion sedimentation due to erosion following a rainstorm in areas that have been badly burned,” he said.
Clauge said making definitive links between the two events is difficult, but that it is an area researchers are increasingly interested in.
The interactive maps, which show a strong correlation between the fire zones and flood affected areas, can help ground some of that thinking, he said.
“They got information on the areas burned and the severity of the burns, they kind of put all this into categories being aware that probably severe fires are the most likely to create that water repellent layer, and then they overlaid the areas where there was flood damage, for example, the Coquihalla corridor,” he said.
“There are some pretty important links between the two, particularly in the Coquihalla, they were able to show that areas of severe flood damage where there were washouts, you know, erosion of the highway, were also areas where they have the most severe of wildfires in the Merritt area.”
Cadell was emphatic that his team are not earth science experts, and said the tool is not meant to prove cause and effect between two events between the fires and floods.
He described the maps instead as a storytelling tool that can help visualize potential linkages and put complex information into terms that are easy for the public to grasp.
Finding ways to visualize the the changing connections between the environment and geography, he said, is even more important amid the effects of climate change.
“Our intent was more about just helping the community at large understand how landscapes changing around us can have a counter or sort of paradoxical effects,” he said.
“That fires can cause floods or a heat dome can cause a flood doesn’t really immediately sort of click in one’s brain, but but here’s a chain of events that allows that to happen. I think that’s the story that we wanted to tell.”