Researchers explore how floods and droughts are challenging science and society globally

Floods, droughts and other water-related disasters are among the costliest natural events to occur in Canada and around the world. Even with significant global advances in science and infrastructure designed to predict and manage such extreme disasters, many communities still face major social and economic consequences when these events occur.

In a new article published in NatureA team from the University of Saskatchewan (USask) and international researchers presented their findings from a global survey to identify gaps in science and policy that need strengthening to better protect the world from drought and flooding.

“Our flood and drought management paradigms are still based on the assumption that the past is representative of the future,” said Dr. Saman Razav, Ph.D., an associate professor in USask’s School of Environment and Sustainability, the Global Institute for Water Security (GIWS), and the College of Engineering in the division of civil, geological, and environmental engineering. Razavi led the Canadian contribution to the study.

“We already know that this assumption is not valid in the context of floods and droughts for two reasons,” he said. “First, as a result of climate change, we are dealing with more extreme events that we have not seen before, such as stronger storms, heat waves or dry spells. Second, due to significant population growth, urbanization, settlements in floodplains or groundwater extraction, more people and assets exposed to floods or droughts.”

Forty-five case studies from around the world were used to evaluate when, where and how current risk management strategies could fail and where possible improvements could be made. The research team assessed floods and droughts that have occurred in the same regions over time to analyze how the occurrence of a first event might affect how a second event is managed.

The study found that when two flood or drought events occurred in the same region at different times, the second event tended to have worse effects than the first, even with infrastructure and policy changes implemented after the first event.

“This counterintuitive conclusion is especially true when the second event is more dangerous or unprecedented than the first — a reality of the world, and especially in Canada under global warming and changing climate,” Razavi said.

After looking at case studies, the team learned some successful strategies to mitigate the effects of a second event through the actions of researchers in Barcelona, ​​Spain, and in the Danube River basin in Germany and Austria. These areas implemented significant risk management changes that reduced the impact of a second water event, such as improving governance and cooperation, using early warning and emergency response systems, and making significant investments in structural and non-structural protection measures. .

USask research associates Laila Balkhi and Hayley Carlson led the collection of data focused on the Ottawa River floods (2017 vs. 2019) and the Assiniboine River floods (2011 vs. 2014).

“We hope this paper can highlight the need for disaster risk management and governance systems worldwide to be more proactive rather than reactive in the way they are set up,” said Balkhi, co-author of the study and a project manager for the Integrated Modeling Program for Canada at GIWS.

“This study provided some insight into priority areas that we need to explore and ways to be more innovative based on what we can learn from each other in different parts of the world,” Razavi added.

The Nature publication is part of a multi-year research program on water resource modeling and management in Razavi’s GIWS lab. Razavi’s team plans to use the insights from this international research to improve flood and drought management practices in Canada.