Dr. John Pomeroy
Canada Research Chair in Water Resources and Climate Change
The key to managing water is developing an improved understanding of hydrology and having accurate models of how vital water resources move through the environment. Unfortunately, the water cycle on the Prairies and in the boreal forest is not fully understood.
“In some climate change models, they basically treat snow as white soil,” he says.
Dr. Pomeroy explains that current watershed models are based on much wetter and more temperate climates. When soils have high water content, a large part of the rain and snowfall ends up in creeks, rivers and lakes. These models are of little use on the Great Plains of North America, where watersheds cover hundreds of thousands of square miles, but very little precipitation ends up as runoff. Most is soaked up by the soil or evaporates. Pomeroy’s own research shows that even in winter, up to 40 per cent of the snow pack on the Canadian Prairies disappears into the atmosphere through sublimation of blowing snow. Other sublimation losses, such as during chinooks, are less well understood.
Accurate computer models to assess water supply are critical both to help communities to adapt and to allow governments to make and implement water agreements. For example, in the Saskatchewan River system, upstream provinces are required to send through a percentage of the natural flow. Without accurate models, there’s no way to know if this is can be sustained, given increasing water use in the basin. Likewise, international agreements drawn up in wet decades may demand that Canada send more than its fair share of water south of the border when the climate gets drier.
Dr. Pomeroy intends to establish a new Saskatchewan Watershed Research Facility (SWRF). The facility will be devoted to gathering data, improving the understanding of prairie hydrology and creating improved computer models that can more accurately predict water supply; the interaction of climate and water; the effects of agricultural and forestry practices; and the impact of climate change.
The University of Saskatchewan academic climate is well suited to this research. An informal poll revealed what is perhaps the highest concentration of water-related research talent in Canada, and the National Hydrology Research Centre is located just north of campus at Innovation Place. This is fertile ground for a new Centre for Hydrology at the University, with the SWRF at its core.
There are already tools and techniques to manage water resources. For example, minimum and no till farming have prevented the dustbowl conditions of the 1930s, in part because stubble traps winter snows that might otherwise sublimate or end up in large drifts, unavailable for crops. However, Dr. Pomeroy says hydrologists haven’t studied how these practices have had an impact on larger scale water resources, have not examined the impact of crop diversification on water nor have they developed accurate models to help us use Prairie water resources wisely. And Nature, as always, has the final say.
“The best we can do in a changing climate is to increase our understanding of hydrology, and then use this to improve the predictive tools for water supply and to develop better water management techniques,” he says.
“The climate has always changed and water-stressed civilizations have always either adapted or perished. We must choose to adapt.”