Fluvial geomorphology. What does that mean? It is the scientific term for the changes that water cause on the landscape, where fluvial means 'of water' and geomorphology is the study of the physical features of the Earth's surface. What a strange way to describe the changes in the landscape, right? Some people think that water is an abundant resource that will always be around and that it has had little impact in the grand scheme of things. Humans have engineered the Earth's surface to be how it is using equipment, force and planning. Though humans have had a major impact on how the Earth's surface looks today, the impacts of water across the globe are immeasurable. We see dips and valleys where prehistoric lakes and oceans once were. Evidence of glaciers, long melted and the impact of the meltwater on the land is still visible today! What may have started as a small flowing stream millions of years ago has cut away millions of years of soil and sediment, creating deep channels like the Grand Canyon! When comparing humans building storm water ponds or moving river channels, years of erosion from water will have the greater impact.
So why should we care about fluvial geomorphology anyway? Well, the way that water flows and where can have big impacts on human activities like where we build roads and infrastructure, how we use the water, and even whether the water is safe or not. Here we can see the Swan River cutting a new path in the Spring of 2021, eliminating our water monitoring grab sample site , forcing us to access the stream at a different location.
Depending on what the bottom of the stream is made of, whether it be sediment, rocks and cobbles, or even bedrock, flowing water will wash away that bottom, bit by bit. There are instances of substances being released through fluvial erosion that create specific habitats downstream that some species have evolved to tolerate, while others have to work to adapt or perish. Considering the surrounding land uses and natural processes around a specific waterbody is critical to understanding things like water quality results since some systems may be naturally rich in a specific metal or nutrient. Take the case of Lesser Slave Lake. The lake naturally has phosphorus rich sediment, which is a nutrient that commonly causes algal blooms during the summer months. Knowing the history of the area can help make sense of the data and avoid questioning where it came from or if a certain result should be more concerning.
Understanding fluvial geomorphology can also help us understand what happened in the past. When visiting places like Drumheller, AB, you can see the layers of sediment in the hills. This is years of cutting and deposits from a time before humans. This is also an excellent place to find fossils because it was an inland ocean which provides an excellent medium to preserve bones and create fossils! Fossil deposits like these are invaluable and help us understand things like who walked the Earth before us, climate, and more!
It is so important to understand our water, where it came from, where it goes and its history. Our water is everything. It is our past, present and future and we need to do what we can to safeguard it for the future. Watershed management is a shared responsibility and it is crucial that we work together to protect it for generations to come.
By: Kate Lovsin