Parts of Alberta and Africa face longer, more severe droughts

Both the severity and length of droughts are increasing in western North America, including the prairies as well as parts of Africa, says a recent study published in Nature Climate Change.

The study, authored by Dr. Tricia Stadnyk, PEng, PhD, professor of civil engineering in the Schulich School of Engineering and geography in the Faculty of Arts, and master's student Michael Vieira, used global climate models to predict some alarming hydrology trends around the world.

“It's reinforcing the sentiment that the wet regions are getting wetter, and the dry are getting drier,” says Stadnyk, the NSERC Tier 2 Canada Research Chair in Hydrological Modelling.

“What really emerged more clearly in this study is there are certain parts of the Northern Hemisphere, specifically the Canadian prairies, that are getting drier and not just a little bit drier, but mean annual runoff was actually decreasing,” she says. “Droughts are becoming more frequent, and the duration of those droughts is getting longer.”

Newer climate models have finer spatial resolution, improved representation of land surface hydrology and the ability to produce centuries-long simulations, which means they are better able to provide “meaningful information” about water.

This most severe classification of drought, called “meteorological drought,” can continue for so long that a region is no longer able to produce food it once could. In wealthy countries, like Canada, this has huge implications for agricultural and other policies that are based on historical data about water supply, rather than projections.

“This study is showing the way in which we do things, where we get our food from, particularly here in the Canadian prairies, absolutely needs to change into the future,” says Stadnyk. “There's going to be even more of a crunch on water supply, and we're going to need every ounce of irrigation efficiency just to keep up with current agricultural demand, let alone expand it.”

The study found that regions in North and South Africa are also facing further prolonged periods of severe drought. This has “unprecedented implications for global stability” as people flee areas that can no longer grow food.

“In North America, we have a wealth of resources where we can innovate our way out by importing food,” she says. “But people in other parts of the world, such as Africa, don't have those options. Mass migration is more likely in those places.”

Initiatives such as the world's first United Nations University Hub focused on water at the University of Calgary will help study severe drought more holistically, looking at environmental impacts, as well as human health, food supply and sustainability. But Stadnyk also suggests that “every single person” be aware of, and take accountability for, the water they use day to day, from long showers to buying almonds, which require a lot of water to grow in drought-stricken California.

“We really need to start thinking about food cycles and life cycles,” she says. “We also need to think about policy and start asking some seriously hard questions. Canada's a water-rich country. We always hear we've got seven per cent of the world's freshwater supply, but that doesn't mean that what we have isn't also precarious.”