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.
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!
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.
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.
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.
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…