Anna Marshall
Tell us about yourself:
My name is Anna Marshall (she/her), and I am a fluvial geomorphologist and PhD candidate at Colorado State University (CSU) working with Ellen Wohl. My fascination with flowing water began early. Growing up in Maine, I spent every chance I could get either submerged in water or building intricate channels of my own. While my love of water was well-defined, it wasn't until I attended Connecticut College for my undergraduate degree and worked with Doug Thompson that I first learned how to study a river in detail. Four years of learning from river systems around the world only made me more curious and led me to pursue a career as a river restoration project manager for several years where I worked on restoring natural function to river systems that had been altered by humans. I joined the fluvial geomorphology lab at CSU in 2019 as a MS student with Ellen Wohl where I looked at hyporheic exchange in headwater mountain streams. I had far too many unanswered questions to stop there and transitioned from studying physically complex headwater streams in the Southern Rockies to even more physically complex and larger rivers (think 10+ channels and an abundance of logjams) in the Northern Rockies.
What is your research about?
My research broadly focuses on form and process in river corridors that creates and maintains geomorphic heterogeneity across diverse spatial and temporal scales (a river corridor being active channel(s), floodplain and riparian zone, and underlying hyporheic zone). I use the term form to describe a continuum of single- to multi-thread rivers and the term process to describe the fluxes of materials within a river corridor and the interactions between materials in flux and the physical configuration, biogeochemical characteristics, and biotic communities of the river corridor. A river corridor’s form and processes influence characteristics such as spatial heterogeneity, nonlinear behavior, connectivity, resiliency, and geomorphic and ecological diversity. I’m using river corridor form in my work to infer geomorphic processes because direct measurement of those processes (e.g., sediment flux sampling, repeat channel topographic measurements) tends to be costly. More specifically, I’m using field, modeling, and remote sensing methods to break down the mechanistic relationships between logjams in channels, the formation of secondary channels, and dynamic channel movement over time, all of which promote geomorphic heterogeneity in a river corridor.
What excites you about your research?
My research provides insight into understanding physical mechanisms that create and maintain complex river patterns and processes and drive more resilient river corridors. I’m really excited to apply this knowledge toward figuring out how we can restore beneficial river corridor processes to systems that have been altered.
What broader importance does your research have for society?
As a geomorphologist, I often think about how landscapes have changed due to natural or human disturbance. Rivers are pretty sensitive indicators of what we’re doing to the surface of the Earth. We can’t restore rivers to a more resilient state if we don’t fully understand how natural rivers function. My work details geomorphic response of naturally functioning and physically complex river corridors and I do so with an intentional angle of making sure this knowledge can be shared for more effective future river management. Enabling rivers to heal is our best hope to address climate change impacts, protect freshwater ecosystems, and equitably provide the benefits of thriving rivers to everyone.
What inspired you to pursue a career in Earth Science?
I was fortunate to grow up with an appreciation and insatiable curiosity of the natural world around me. The more places I explored, the more I also saw how rivers were threatened by climate change, dams, pollution, outdated laws, and maybe greatest of all, a lack of awareness of how important rivers are to our lives. In many ways I think it was this realization that made me want to pursue a career in earth science. I felt if I could start to understand the intricacies of river systems and share that knowledge with others, it might change public perceptions, policy, and management of river systems!
What are you looking to do after you complete your PhD or postdoc?
My favorite thing about what I do is getting others excited about the importance of river systems and the connectedness of earth science. I hope to transition that passion into a permanent faculty position. My long-term goal is to build an interdisciplinary and inclusive research group that is working to address local and global water challenges.
Given unlimited funding and access to resources, what is your dream project that you would pursue?
I keep a running list of dream project ideas that I’m constantly adding to. One thing I’ve been thinking a lot about lately is the future of rivers in the Anthropocene and the dilemma of restoring to pre-disturbance landscapes (think natural functioning rivers pre-European settlement) or restoring a river corridor to future resiliency. There is still a major disconnect between what people perceive as natural in rivers and that bleeds through in how we advocate for and manage river systems. I’d love to work toward bridging the gap between research and practice and shifting perceptions as we think about the future of rivers. I’m also really excited about the future of pairing field and remote sensing methodologies. There’s a huge need and endless applications for high-resolution LiDAR so I’d like to see more of that data become accessible (and even more of a plus if it is topobathymetric). And I’m excited to think about research using the new SWOT satellite (surface water and open topography) that can scale up projects and our thinking of freshwater systems around the globe.
What else do you do? Any hobbies or interests outside of work?
Spending time on rocks and in rivers blends work and play in my field. Laughably, when I’m not working, I still spend much of my time exploring mountain and river environments where I enjoy skiing, climbing, kayaking, and backpacking. I also love watching my little garden grow and cooking with whatever it produces!
If you would like, please provide a link to your personal website:
You can check out more of what I'm doing at www.annamarshall.rocks!