Laurentian University professor's research could help prevent floods
Important link between plants and how rivers move, says Laurentian University researcher
A new article co-authored by Professor Alessandro Ielpi and published Dec. 2 in the journal Nature Geoscience could reshape the way we think about the interrelationship between plant life, rivers and the earth.
Ielpi is an assistant professor of sedimentology in the Harquail School of Earth Sciences at Laurentian University.
Ielpi has analyzed a number of rivers around the world, focusing on rivers that flow through deserts.
"These are the type of rivers that have long been ignored by geoscientists because they're very limited in space," said Ielpi. "In fact," he added, "they occur only in two or three places on earth where the climate is so arid that no vegetation can grow at all."
Ielpi says these rivers are enormously important.
"By observing how they behave during floods, we can actually assume that rivers that were on earth before complex life evolved behaved in a similar fashion," he said.
Ielpi explained that every time there's a flood, a riverbank shifts a little bit.
"There's always a little bit of erosion on one side . . . a little bit of sediment is deposited on the other side," he added.
Over time, the patterns are very consistent and the bed tends to shift laterally year after year.
Ielpi says the Vermilion River near Sudbury is a beautiful example of a meandering river that migrates a little bit every year.
According to Ielpi's research, the more vegetation there is along a river's edge, the longer it will take for the river to change shape.
"As the river moves it will transport sediment downstream and together with the sediment, it will transport organic carbon," said Ielpi.
The less vegetation there is, the more likely the river course will change, leaving organic carbon exposed and oxidized more often. This process releases carbon dioxide, which is a proven greenhouse gas, into the atmosphere.
Ielpi says his research may help scientists understand how post-industrial climate change is affecting rivers worldwide.
"This model potentially has impact on infrastructure and flood prevention and future planning for urban areas," he said .
It could also help predict which areas are more vulnerable to erosion
The data model he and Professor Mathieu Lapôtre of Stanford University developed could even be used to understand how rivers might have behaved on other planets such as Mars.
With files from Jessica Pope