Watching the river flow

Watching the river flow

The Université de Montréal's researchers fish for answers to keep our rivers healthy
March 1, 2006
Rivers are complex natural systems that play a crucial role in the development of communities, the survival of species, and the health of human beings. That’s why it’s essential that we gauge how our rivers are affected by environmental change. However, predicting such responses can be a murky task. Currently, many scientists rely on a trial-and-error approach to investigating river processes, which is costly and somewhat ineffective. Fortunately, state-of-the-art infrastructure for field research into river processes at the Université de Montréal is giving scientists innovative tools to plumb the depths of Canada’s rivers.

At the heart of this infrastructure is a unique array of field equipment to measure river velocity and assess how riverbeds and sediments respond to the flow of water. These tools include acoustic Doppler velocimeters, global positioning systems, underwater camera devices, and meteorological stations. With this equipment, researchers at the Université de Montréal are gathering data on river dynamics, the movement of sediment, and fish habitat—three factors that can have a huge impact on our water supply.

“Most of the population of Quebec is along the St. Lawrence corridor. If we want to address the simple problem of water intake for cities and towns, we need to know if these water intakes are going to be buried in sediment in 50 years’ time,” says André Roy, Canada Research Chair in Fluvial Dynamics at the Université de Montréal.

In an effort to find answers, Roy and his team of researchers are spearheading three projects that promise to help keep our rivers healthy. The first involves studying the effects of climate change on the tributaries of the St. Lawrence River. Funded by leading research groups, the initiative involves modeling and predicting the impact of water-level fluctuations caused by factors such as global warming on tributaries and river processes.

Equally interesting is Roy’s exploration of the impact of fish habitat degradation. This project focuses on how young salmon use their habitat and on the long-term effectiveness of in-stream structures such as flow deflectors. These structures are often used to redirect the flow of water, thereby reducing flow velocities and altering fish habitat.

The third project investigates the impact of agricultural practices on rivers that drain into lakes. These bodies of water are often the most severely affected by fertilizers and run-off contamination. That is why Roy and his team are also assessing the effects of new agricultural practices on sediment loads in the Tomifobia River in Quebec’s Eastern Townships.


By using cutting-edge tools and technologies to explore river processes, Université de Montréal researchers aim to minimize the influence of climate change, fish habitat degradation, and poor agricultural practices on our rivers.

“Pollution, land degradation, urbanization, expansion—they’re all having a huge impact. Dr. Roy’s research is fundamental when it comes to reducing degradation and redesigning rivers,” says Joseph Desloges, professor of geography at the University of Toronto.

The effects of climate change and human activities are a primary focus of Roy’s work. Experts predict that water levels in the St. Lawrence River could decrease by as much as one metre as a result of climate change. This drop in average water levels could cause major transformations in river dynamics. By studying the effects of factors such as global warming, Roy and his team are helping to identify the most at-risk areas. This knowledge will play a key role in creating measures to sustain the river ecosystem.

That’s good news for today’s dwindling salmon population. Over the years, salmon habitats have been severely degraded. Even the once plentiful Atlantic salmon has made its way onto the endangered species list. Researching how salmon use their habitat promises to help change that. By assessing the effectiveness of intervention structures such as flow deflectors and understanding the effects of turbulent flow on fish behaviour, researchers stand a chance of rehabilitating today’s rivers.

“The physical environment in which salmon breed, live, and migrate is important to understanding how they function and whether modifications to the flow of the river will have consequences,” says Peter Ashmore, professor of geography at the University of Western Ontario.

Poor agricultural practices have long been identified as a major source of erosion and pollution in rivers. The cultivation of crops causes chemicals from fertilizers and pesticides to seep into the groundwater. Fortunately, Roy’s ongoing assessment of the impact of land use on sedimentation could lead to the adoption of less harmful agricultural practices.

But that’s not all. While most research into river processes is conducted in laboratories, the Université de Montréal’s equipment allows Roy and his team to install five permanent field sites scattered across the Eastern Townships and along the St. Lawrence River. Now Roy can conduct a real-time—and real-life—exploration of river dynamics and discover how rivers respond to environmental change over the long term.

“The flow of rivers is often examined in laboratory settings,” says Ashmore. “Dr. Roy’s taken on the job of figuring out what things look like in a natural environment where measurements are difficult. That’s significant.”


Roy and his researchers aren’t alone in their quest for knowledge about river processes. The Natural Sciences and Engineering Research Council (NSERC) and the Ouranos Consortium on Regional Climatology and Adaptation to Climate Change have partnered with the Université de Montréal as part of a strategic grant program. Some of the research is conducted under the umbrella of the multi-institutional Global Environmental and Climate Change Centre, which is funded by the Fonds québécois de la recherche sur la nature et les technologies (FQRNT), a Quebec agency that supports research, knowledge sharing, and training.

The program also involves researchers from several institutions in Canada and Europe. And because students are the cornerstone of any research project, five undergraduate assistants, 10 graduate students, and two post-doctoral fellows are now trained in the program.