A new web application designed by Western Arctic Centre for Geomatics allows anyone to peruse more than 30 years of satellite imagery of the Northwest Territories at just the click of a button.
An explanation of how the Long-term Change Detection (LTCD) project works was given during the Aug. 11 Aurora Research Institutes Speaker series, which resumed in-person presentations earlier this summer.
“We can quickly show land feature changes by their colours,” said Jiaao Guo, who designed the application along with Steve Schwarz, Jurjen van der Sluijs and Jenny Tjhin. “Previously, this was not really doable, but in the past 10 years technology such as Google Earth engine have improved. What we’re creating, it’s not just data sets we’re providing but more of a living document and a service our intergovernmental partners and partners across Canada to better understand the picture.
“The general idea is the human eye has a very narrow range of what it can see on the electromagnetic spectrum, whereas a satellite has a much wider range by having multiple bands it can see reflecting from the surface.”
Using Google Earth and Landsat Imagery, which includes 35 years of satellite photos of the Northwest Territories, viewers can get a big picture view of how coastal erosion, urbanization, mining activities and wildfires have changed the landscape over the last quarter-century. Glacier retreats and movements can also be observed.
Time lapses of key files like the coastal erosion around Tuktoyaktuk from 1985 to 2021 are also available. While the software uses data going back to 1985, the Landsat system was initially launched by NASA in 1972.
Data of what’s changed is showcased in colour schemes, with darker shades representing lower numbers and brighter colours representing higher numbers. Each colour corresponds to a particular type of information, for example blue is used to represent shoreline erosion, with lighter shades of blue indicating increased amounts of erosion and darker shades showing less.
It also includes a users guide in both French and English for researchers and casual map lovers alike. Once users have a bit of know-how, they can join the workspace and help contribute to the growing knowledge base and access data accumulated from a wide variety of sources, from traditional knowledge to scientific data. More than 20,000 photos are also available — and that’s just the 2020 collection.
Since its initial trial-run in 2021, the application has gotten a lot of use. Guo noted the Cultural Places Program has used the LTCD project to track melting ice patches, the fire history of forests and to quantify other observations of coastal erosion around Tuktoyaktuk.
Other users of the application include the GNWT’s Forest Management division, the NT Geological Survey and Wilfred Laurier University.
“If you happen to be a researcher and you want to contribute, play around or see the data, then contact us and we’ll assign you a console,” he said. “We actively encourage people to come in and see what’s happening.
Visit https://arcg.is/0Tez0z to check out the program for free.