Fluvial geomorphology is not dead

For those of you wondering WTH fluvial geomorphology means, it’s the study of river/stream processes and the landforms they create. Ben Hayes, the director of the Susquehanna River Initiative, has a nice description of it on his webpage, while Dave Sauchyn at the University of Regina has a comprehensive summary of the processes fluvial geomorphology includes.

Unfortunately, fluvial geomorph often doesn’t get the credit it’s due.

A few years ago, our department was reviewing the BSc curriculum to streamline the degree and offer courses that more than one faculty member could teach (the joys of managing reductions in both funding & staff). A colleague suggested we get rid of the Fluvial Geomorphology course because it was a dead/irrelevant science.

To say I was shocked would be putting it mildly. I’d come from a term position where I taught Fluvial Geomorph to a keen group of students who enjoyed it AND found it highly relevant.

More recently, the news of flooding in Europe, India, and Canada makes the case for fluvial geomorphology not being such an obsolete subject after all. This article by University of Calgary geology professor Jerry Osborn about the Alberta floods is particularly relevant. In it, he notes that he and many other professors have often used Cougar Creek (the community in Canmore that was devastated by massive overland flooding & stream channel migration) as a classic example of “inane mountain development”. Fluvial geomorphologists are well aware of the perils of constructing neighbourhoods on an “active alluvial fan” (Canmore), and on “point bars on the insides of meander bends (Bow Crescent) and adjacent to abandoned meander loops (Roxboro)”. Fluvial geomorph principles can be applied not only to examine what happened during this event, but also to assess the potential effects of future floods.

Now that’s an example of a highly relevant, non-dead science!

Fluvial geomorphology is important to a range of topics you might not have considered.

1. In river restoration, river shape (morphology) is examined as a function of watershed characteristics. This information is then used to try and return the system to its ‘natural’ state based on our understanding of the fluvial geomorph processes that drive this morphology.

Long profile

Long profile of a river within a catchment, showing how fluvial processes change from headwaters to river outlet.

2. Streambed morphology is critical during many salmon lifecycle stages, and is driven by fluvial geomorph processes. For example, salmon prefer to spawn in areas of a river bed that have water exchange between surface and groundwater. Identifying these locations requires knowledge of fluvial geomorphology. Changes in river flow can have a major impact on the river bed, thus affecting salmon spawning locations. And it’s not just the riverbed that has an effect on salmon, but salmon themselves can actually change river morphology and drive sediment transport!

salmon habitat

Salmon spawning outside Valdez, Alaska (Photo: D. Cowals).

3. Where dams are proposed, installed, or even being decommissioned, fluvial geomorphology can provide information on what will happen to the river system downstream of a dam. The installation of the Kemano Dam in northern BC, for example, caused the downstream channel to widen and – following a major flood event – material on the river bed was scoured out by increased water flow. The removal of the Elwha Dam in Washington State resulted in massive sediment transport downstream – the system continues to stabilize in response to both these inputs and changes in river flow patterns. Finally, studies into the feasibility & environmental impact of the Site C dam project (BC Hydro calls it the ‘Site C Clean Energy Project’ – it’s all about the marketing) proposed for northern BC are measuring fluvial geomorphic processes to define potential impacts.

elwhasediment

Sediment release following Elwha Dam removal in Washington State. (Photo: T. Roorda, Seattle Times).

4. Fluvial geomorph can help define connections between surface- and ground-water sources. This is especially important for floodplain ecology, which often depends on shifts in the location of groundwater-surface water connections to maintain habitat diversity of plants and aquatic organisms across the floodplain. This cool shot from a NASA camera shows the changes in the floodplain around Calgary after the flooding.
5. Knowledge of fluvial geomorph is critical for engineers constructing highways near rivers, and bridges over those rivers. The recent Alberta floods did significant damage to transportation infrastructure, and rebuilding will have to take fluvial geomorph principles into account.

hwy40_rivermeander

Flooding along Hwy 40 in SW Alberta eats away at infrastructure (photo: Calgary Herald)

6. With the ongoing wildfires in the southwest US, fluvial geomorphology is very important in understanding how the landscape will respond to streamflow events driven by both snowmelt and rainfall. This photo from my last blog post illustrates how extensively stream channels in burned watersheds can be altered when floods occur.

LynxCkDevastation

A research installation demolished by flooding on Lynx Creek, Crowsnest Pass. This area was burned in 2003 (Photo: Southern Rockies Watershed Project)

These are only a few of the ways in which fluvial geomorph is important to our everyday lives. Next time you hear someone say it’s a dead science, you know what to tell them…

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7 thoughts on “Fluvial geomorphology is not dead

  1. Fluvial geomorphology at the U of L was one of my most inspiring classes. I loved walking the Oldman coulee early in the morning as our class identified different features. Thanks for the great post!

      • Hi,
        I have a photo of an uusual seaside rock formation (a pool like a pot half-raised on a potter’s wheel) and a geologist friend says I need to ask someone who specialides in ‘fluvial processes’ about it – I’d love to know how it was formed. (I know about sand and rocks and water forming holes in rocks, but this seems very different. I’ll happily e-mail you the pic. Regards,
        Hilary Lamont hml@btinternet.com

  2. Fluvial geomorph is so active below glaciers, that it makes discharge measurement quite difficult with the constantly changing stream bed. Hence, the USGS does not put gages near glaciers in the turbulently flowing and evolving streamss.

    • We’ve had the same problem at field sites – can’t get a continuous measurement not only due to changes in the stream bed, but also channel migration etc. Love those dynamic environments, but they’re a pain in the butt to measure.

  3. Pingback: Morsels for the mind – 12/7/2013 › Six Incredible Things Before Breakfast

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