Severe droughts a threat to major watershed
New Queen’s research shows severe droughts could threaten one of Canada’s major watersheds. The study, focusing on changes in water levels in the Winnipeg River Drainage Basin (WRDB), determined future droughts could be much worse than anything previously recorded before.
Using a newly developed technique, lead researcher Kathleen Laird (Biology) reconstructed past changes in water levels in a network of lakes over the past 2,000 years. “It was a very telling study, and very important. Although water levels are now at an all-time high, our reconstructions show that during a past period of warmth 1000 to 800 years ago (a period commonly referred to as the Medieval Warm Period), there was a megadrought that lowered lake levels in all of our study sites. ”
The drought of the 1930s is a benchmark that currently helps define a significant and severe drought event that would limit hydropower generation. The WRDB, an important source of water for Manitoba Hydro occupies a large portion of northwestern Ontario. A severe drought can drastically reduce power generation, which can cause a net loss of hundreds of millions of dollars to utilities, prompting them to fund the Queen’s led research on past variations in water levels.
“We are rolling the dice with climate change,” says Brian Cumming (Biology and Environmental Studies). “We do know that based on this data, the drought in the 1930s was not as extreme as compared to what has happened in the past, and consequently could occur again in the future. We could be headed for big changes.”
The Queen’s team, including biology master’s students Melanie Kingsbury, Susan Ma and Heather Haig, is funded by the Natural Sciences and Engineering Research Council of Canada and Manitoba Hydro.
The researchers continue to study climate sensitivity of the WRDB region, with respect to water levels and the link between drought and forest fires.
The research will appear in Global Change Biology.