Researchers came to this conclusion after studying 70 lakes near Old Crow, Yukon, and Churchill, Manitoba. Most of the lakes studied are less than one metre deep. According to the analysis, more than half of those located on relatively flat terrain and surrounded by scrubby vegetation show signs of desiccation. The problem stems chiefly from a decline in meltwater; for instance, from 2010 to 2012 average winter precipitation in Churchill decreased by 76 mm compared to the averages recorded from 1971 to 2000.
The drying of some lakes, which first became visible to the naked eye in 2010, was even more pronounced in summer 2013. "With this type of lake, precipitation in the form of snow represents 30% to 50% of the annual water supply," explained the study's lead author, Frédéric Bouchard, a postdoctoral fellow at Université Laval's Department of Geography and the Centre for Northern Studies.