Yuan Li
Tell us about yourself:
Hello! I’m Yuan, and I am a PhD candidate at the University of Virginia working with Dr. Ajay Limaye. Prior to my PhD, I completed a Master’s degree in Marine Geology under the supervision of Dr. Ya-Ping Wang at Nanjing University, China. I am broadly interested in how water interacts with sediments, and I employ numerical models to understand how this interaction changes the landscape over time.
What is your research about?
My current research focuses on understanding how rivers change their courses. The channel of many meandering rivers migrates laterally, which shapes the landscape and poses erosion hazards to engineered structures. Many numerical models have been established to understand this migration, but their predictions often deviate from observations. In my work, I developed a framework to test these models, so that we can know where and when the model might go wrong. Using model experiments, I also tested how the timescale of the morphodynamic feedback between channel geometry and lateral migration impacts the channel trajectory. Currently, I am building a dataset from remotely sensed images, and from it I hope to find new patterns of channel evolution that can be incorporated into existing numerical models.
What excites you about your research?
I am fascinated with how numerical models with simple rules can be used to depict complex landscape changes. During my time in the Landscape Evolution Group at the University of Virginia, I’ve been exposed to models not only describing meandering channel migration, but also hillslope formation, channel braiding, and eolian dune evolution. Understanding what a model parameter stands for in nature and how it connects to the rule that guides water and/or sediment movement is always a fun part in my research. I enjoy learning new models, finding their connections and differences, understanding how these models are used to solve real world problems, and how my work can probably improve them.
What broader importance does your research have for society?
Rivers are hubs of human civilizations. They play a crucial role in sustaining ecosystems, providing freshwater for agriculture and human consumption, and facilitating transportation and trade. They are also dynamic features on Earth, with some of them migrating up to 100 meters per year. Channel migration results in erosion and redistribution of sediment, which builds stratigraphy, shapes riparian habitat, and jeopardizes built structures. My work aims to further improve models for channel migration, which leads to more accurate reconstructions of historical river dynamics, assessments of erosion and flooding hazards, and predictions of future landscape evolution.
What inspired you to pursue a career in Earth Science?
When I was a child, every summer I would visit my maternal grandparents who were living in a small coastal town called Changli in the Hebei Province of China. There are big sand dunes up to 40 meters high, and people like to sit on a wooden board and ‘surf’ down the dunes from their top. I enjoyed that activity, but when I grew up, I was surprised to learn that not every coast looks like the one in Changli. This experience ignited my curiosity to understand why there are diverse appearances of the Earth’s surface. After conducting several research projects focusing on coastal and river morphodynamics in graduate school, I find that answering this question requires lots of knowledge, such as those about tectonics, climate changes, vegetations, and sediment dynamics. Therefore, I’d like to explore more about it.
What are you looking to do after you complete your PhD or postdoc?
In the short term, I am looking for a postdoctoral position where I can learn new skills and expand my knowledge on landscape evolution. I hope to learn and build flumes and physical models, which is not the focus of my PhD but is a powerful tool in studying river morphodynamics. I also enjoyed sharing the knowledge and skills I gained along the way through teaching and mentoring, so in the long term, I hope to become a geomorphologist as a faculty member in a university.
Given unlimited funding and access to resources, what is your dream project that you would pursue?
I would say I want to label all river streams with information about their bank type, vegetation, hydrodynamics, spatial dimension, climates, historical human modifications and so on, and see whether we can extract a universal rule that can explain the future motions of them.
What else do you do? Any hobbies or interests outside of work?
Outside of work, I like swimming and hiking. Although I am currently not a very skilled swimmer, I enjoyed the peace in water and me actually interacting with water. Hiking is a way for me to get exposed to the mother nature. It makes me feel good and capable of doing things.
If you would like, please provide a link to your personal website:
https://yuannli.weebly.com/