June 18, 2018

UCalgary researchers contribute to science of flooding

Scholars improve what we know about impacts on people, structures and the environment — and how to mitigate against future disasters

It’s been five years since southern Alberta was hit by a 100-year flood event that saw heavy rainfall contribute to the worst flood in the province’s history and one of the costliest disasters ever experienced in Canada.

This summer, a University of Calgary researcher is embarking on a climate change adaptation demonstration project to try and prevent or at least reduce the impact of the type of flooding that occurred through better water management.

“It involves a different approach to land use that would try to maintain and manage water on the land differently and not just focusing on pushing it off as fast possible back into the river,” says Dr. Mary-Ellen Tyler, professor and former dean of the Faculty of Environmental Design.

Climate change is believed to help intensify weather patterns. Not just rainfall, but also hot dry spells as well. So during flood season in the spring and early summer, rainfall and runoff that can overwhelm traditional flood mitigation, says Dr. Tyler, PhD. In addressing flood conditions, Tyler said other weather patterns must also be taken into account.

“We’re seeing extreme weather that we didn’t build for 70 years ago, or even 30 years ago,” says Tyler. “And the other side of it is drought. So how do we adapt our land use to mitigate both drought and flood by managing the land’s performance  in terms of its ability to hold water and keep water managed over time in both times of flood and drought. Look at how on a watershed scale regionally we might be able to start looking at how to manage the amount of runoff we’re creating and look at different ways of managing the water within the landscape itself.”

This is just one of many research projects that is planned or has been conducted by the University of Calgary to address the issues caused by flooding. Researchers with Schulich School of Engineering are looking at various aspects of flood events from how the watershed absorbs rainfall and runoff, to how urban development can contribute to intensifying the impact of a flood. Geographers are working with drones to map flood plains and track the changes caused by the 2013 flood in southern Alberta. Meanwhile, researchers at the Faculty of Social Work are looking at the impact on people and communities.

Return the watershed to its natural state as a sponge

The need to address the combined impact of climate change and urban growth on the watershed appears pressing, according to a recent study released in March by a postdoctoral fellow in geomatics at the Schulich School of Engineering.

Dr. Babak Farjad, PhD, and his team investigated the combined effects of future climate and land-use/land-cover changes on the Elbow River watershed, concluding that changing precipitation patterns, warmer springs and reduced natural absorption in riverside communities means Calgary’s risk of flooding will increase greatly over the next 50 years.

Heavy snowfall, increased rain and rapid spring melts due to warmer temperatures are all significant contributors to flooding, but it’s human development that aggravates that potential by replacing natural groundcover and forest with buildings, asphalt and concrete.

“The combined effects of climate change and urbanization have left the watershed more vulnerable to flooding events,” says Farjad. “Climate change has led to weather events with greater intensity and urbanization has meant that water cannot reach the soil to be absorbed.”

Farjad can’t predict when the next flooding event might come or how frequently they may happen in southern Alberta but he can suggest ways to mitigate the risk.

 “We can try to return the watershed to its natural state as a sponge. And in the urban environment, we can look at ways to add green space, rooftop gardens and improve drainage systems,” says Farjad. “We should improve flood warning systems to give people more time to prepare when a flood does occur.” 

A group of students use borehole logging to obtain detailed information of the stratigraphy beneath the river. By better understanding previous floods, it’s hoped the effects of future floods can be predicted.

Students use borehole logging to obtain detailed information of the stratigraphy beneath the river.

Riley Brandt, University of Calgary

Use more rigorous and frequent monitoring of bridges and buildings

In the Department of Civil Engineering, Dr. Mamdouh El-Badry is looking at how to improve monitoring techniques so that any flaws or weaknesses emerging in bridge infrastructure over time can be caught and fixed before a disaster such as a flood comes along to exploit the problem with catastrophic consequences.

The current practice is to visually inspect bridges every two years and buildings every five years for potential issues, says Dr. El-Badry, PhD. But his research could lead to much more rigorous monitoring.

“I believe continuous inspection is important,” says El-Badry. “There are structural health monitoring techniques that can allow for continuous monitoring of the behaviour of bridges and buildings.”

Using digital cameras connected to computers, and sensors that detect movements and vibrations, it is possible to remotely and continually track the impact of traffic, snow and spring run off on bridges; this type of monitoring can apply to all infrastructure, says El-Badry .

“We have the tools, we have the sensors, and we are working on developing the techniques that would allow these tools to be used continuously in different types of structures,” says El-Badry.

“In collaboration with geomatics engineering researchers, we are developing image-based techniques to detect surficial cracks and fractures, determine their width and extent, and investigate their causes and effects. We are also developing vibration-based techniques that allow us to detect and identify internal and hidden damages and flaws and estimate their severity. This information can help infrastructure owners and managers make decisions on the necessary measures for maintenance and/or repair.”

Long-term recovery can take much longer than people think

While much research focuses on the environment, both built and natural, University of Calgary researchers are also looking at human impacts of disasters including floods.

Social Work professor Julie Drolet is one of the leaders of the Rebuilding Lives Post-Disaster Research Partnership and Alberta Resilient Communities Project, which are both focused on the realities and challenges of disaster recovery for individuals and communities. Building on recent research, it is evident that social workers are playing an increasing role in disaster preparedness, emergency relief, and long-term recovery.

“I think increasingly the thinking is that communities are never really the same after a disaster,” says Dr. Drolet, PhD. “I think that increasingly the feeling is you return to a new ‘normal’ — a different ‘normal.’ An experience like that is more like a journey, you arrive somewhere else and things will never really be exactly the same as they were.”

“Social workers play a key role before and during a disaster and in long-term recovery, which can take much longer than people think.”