Predict the unpredictable: | Yorkton this week
SASKATOON – The world is changing rapidly and the past is no longer a guide to the future in terms of extreme events and flooding.
This is one of the findings of a report on the Changing Cold Regions Network (CCRN), a summary of the research program that ended in 2018 and which recently compiled many of its scientific advances in an issue. special of the magazine. Hydrology and Earth System Sciences.
The CCRN’s research aimed to improve forecasting and prediction models to better understand the challenges that western and northern Canada may face in the future as the planet warms.
Unprecedented events like Fort McMurray, Alta., The forest fires in 2016 and the flooding in Calgary in 2013 could start to become more common and more severe, said Dr. Chris DeBeer, Scientific Director of CCRN and Pan-Canadian Global Water Futures (GWF). program, led by the Global Institute for Water Security (GIWS) and the University of Saskatchewan Hydrology Center (USask).
“Being able to better understand what the future may hold in store for us is very important for society, for our water resources and for infrastructure and health and many other related things,” said DeBeer.
It turns out that grasslands, mountains and the north can be difficult to model.
“Surface water connections don’t exist all the time, and much of the prairie landscape is covered in glacial depressions that only connect periodically,” DeBeer said. “It has always been a challenge for standard models to represent this.”
CCRN research has improved the ability of the models to represent the hydrology of western and northern Canada, which has unique features such as permafrost and glaciers. GWF, an expanded CCRN monitoring program, advances models and focuses on all of Canada as well as the cold and high mountain regions of the world, which provide water to a large portion of the world’s population. .
“These are tough environments,” DeBeer said. “Processes such as snowmelt and infiltration in frozen ground and freezing and thawing of soils – the processes of cold regions are unique and difficult to represent in computer models.”
Climate change is also impacting landscapes and land cover, such as agriculture and grasslands that creep north, shrubs encroaching on the tundra, and deciduous trees replacing conifers in the boreal forest. These changes can impact the predictions made by these models.
Dr. Jennifer Baltzer, Associate Professor and Canada Research Chair at Wilfrid Laurier University and Principal Investigator at GWF, was part of the CCRN and focused on changing land cover at high latitudes.
If you change the type of vegetation, it impacts a range of processes, including how snow and rain are intercepted to how much water returns to the atmosphere, Baltzer said.
“The type of vegetation that you have in these areas has strict controls over some of these physical exchanges related to water and energy,” she said.
CCRN research captured key climate change-induced vegetation transition scenarios in simulations of the land surface models that Environment and Climate Change Canada (ECCC) and the CCRN were using.
The models have a range of different types of land cover that are used in the scenarios they run. Baltzer said that by changing land cover, we can begin to assess the implications of vegetation change induced by global warming.
Hydrological and land cover models are developed in parallel. An important step is to bring these models together to improve the accuracy of our forecasts, Baltzer said.
“If you try to anticipate one and ignore the other, you’re not going to do things right because the two are talking to each other and interacting.”
A national effort to improve emergency response
The GWF program is working with ECCC to improve its operational forecasting system, which can help inform emergency response management, including when provinces issue flood forecasts.
The researchers worked on improving the platform for hydrologic modeling of small-scale cold regions and the large-scale MESH (Community Environmental Modeling – Surface and Hydrology) model – the hydrologic diagram of the Earth’s surface of the modeling system. ECCC Community Environmental Policy.
This is a system that has followed the scientific advancements of CCRN and GWF and applies the model to major river basins in Canada, including the Great Lakes – St. Lawrence, Saskatchewan – Nelson, Mackenzie, Fraser, Columbia, Saint John and Yukon.
“Together, we are developing a national framework that is linked to the ECCC framework,” said DeBeer. “We’re making progress in different parts of the country on physics and how we manage these models, and we can use that science to make it happen.”
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