Drones reveal how flooding altered the Elbow River

Researchersare using drone technology to assess and study the aftermath of the Calgary floods from two years ago.

We don't have a lot of opportunities to examine what floods do to the landscape.- ChrisHugenholtz

The study began in 2012 as a test for the use of drone technology to map river systems and fish habitats in the Elbow River.

After the 2013 floods, researchers were able to re-visit the area and map it once again. This allowed them to assess how significant the changes in landscape were by comparing very precise and accurate 3-D maps and models of the area from beforeand after the floods.

"We don't have a lot of opportunities to examine what floods do to the landscape andwe don't usually have the conditions before the flood to use for reference, so this was an opportunity to have that before and after," says Chris Hugenholtz, an associate professorin the department of geography at the University of Calgary.

A 3-D shape of the river is difficult to get using traditional geographic methods of research. Aerial mapping allows researchers to take photos from all angles and combine them to reconstruct the shape of the river.

A changed river

The team's research concluded that the flood completely restructured the flow in the area of the Elbow River by Redwood Meadows. They found that there were locations along the bank where upto 150metreshad been eroded. The findings were published online recently in the Earth Surface Processes and Landforms journal.

Aaron Tamminga, a PhD student at UBC who led the project and the publications related to the research, says it will take a larger flood than before to re-shape the landscape in any significant way in the future.

"The river readjusted after such a big restructuring event," he says. "Smaller events cannot rework things as easily."

Going forward, Hugenholtz says he hopes to improvethis use of drone technology to support emergency and disaster management.

"We're looking to partner with different organizations in the city and province to figure out ways of implementing technology to give more operational measurements and to understand what's taking place," he says.

The study involved researchersfrom the University of Calgary and the University of British Columbia.