Degree Seeking: PhD - Watershed Science
Faculty Advisor: Dr. Jack Schmidt
Research Area: Quantifying the magnitude of a sediment mass imbalance necessary to cause channel adjustment: What constitutes a big number?
Christy Leonard (PhD candidate, Watershed Sciences) started her career on the muddy side of science. She had just completed an undergraduate degree in geology from the University of Vermont, and drove cross country to California for a position with the Army Corps of Engineers to work on flood protection projects in California’s Central Valley. She was surprised, in that state, by the vast stretches of desert, the excellent tacos, and by the cultural contrast of water management from what she had known growing up in the Midwest.
“The network of levees and dams in California’s Central Valley was unlike anything I had ever seen in Indiana. I couldn’t believe the massive amount of infrastructure needed for people to grow food, have water for their homes, and safely live in flood prone communities,” she said.
Working for the first time for a major water resource agency in the arid west exposed her to the challenges and complexities of western water resource development. Growing up in a rural community in the Midwest, she was acutely aware of agricultural practices and norms, but water for irrigation in her home state of Indiana primarily came from the sky.
The experience changed the focus of her career … from geology to fluvial geomorphology, and from the geologic perspective of millions of years to more applied management questions that unfold over the relatively quick arc of decades. In 2015, she received a Masters Degree in Geography/Water Resources from the University of Wyoming, and continued to work for the Army Corps of Engineers until 2017, when she started her Ph.D. program at Utah State University. Leonard realized the deep implications of water management decisions in the west, the complexity of the issues, and the importance of backing up solutions with science.
“I realized pretty quickly that if I wanted to have a voice in the solution, I needed an advanced degree … one that would allow me to develop critical thinking skills to break down the components of these intricate challenges and figure out which questions are important and worth pursuing, even if those questions have not been the traditional focus of managers.”
Leonard currently works with an existing system of sediment gages on the Green and Yampa Rivers in Dinosaur National Monument, Utah downstream of Flaming Gorge Dam. These gages project sound waves to measure the amount of sediment moving into and out of a river reach every 15-minutes, producing a mountain of data that managers use to determine whether sediment is being stored or eroded from the river, and what kind of dam operations cause those movements. Managers hope these data will be useful in linking changes in reservoir releases to changes in endangered fish habitat; but data from these sediment gages only implies change, it does not directly measure the change in the river.
Leonard’s research will close this research gap by relating the measured change in sediment storage to on-the-ground changes in the river’s shape and form. She wants to understand how much sediment storage or erosion needs to occur before significant, and potentially detrimental, changes in aquatic habitat actually happen. She asks – Is the measured amount of sediment stored within the river causing the river channel to narrow? When should managers be concerned that the amount of sediment at the gages signals damage to endangered fish habitat? How can we change reservoir releases to stop this from happening? Leonard’s research aims to answer these questions and provide managers a framework to predict how changes in reservoir releases will impact endangered fish habitat and other river ecosystem resources.
Christy at CCRS
Working with the Center for Colorado River Studies has two advantages, said Leonard. It gives her the space to struggle through critically thinking outside the box, to find unconventional solutions to applied problems. Although she has resources for mentoring, she doesn’t have anyone directly dictating the questions that need answers, or how the results should fit in a neatly tied package.
“It’s a hard prospect not to be instructed on a direct deliverable to a question that has already been proposed, but it is ultimately an advantage,” she said. “It forces me to consider which questions are important and understand how answering those questions will inform innovative solutions to applied problems.”
Her experience at CCRS has also allowed her remarkable opportunities for networking and building partnerships. She has worked with the USGS Grand Canyon Monitoring and Research Center, the Upper Colorado River Endangered Fish Recovery Program, the National Park Service, the Bureau of Reclamation, and others to stay engaged in management applications of her research.
Poster: Linking High Temporal Resolution Flux-based Sediment Budgets with Channel Change: Establishing morphological meaning to measurements of sediment flux
Paper: Interpreting flux-based sediment budgets in a habitat context: Linking precise temporal-resolution measurements of sediment flux to spatially robust characterization of channel change
Published Research: Measuring channel planform change from image time series: A generalizable, spatially distributed, probabilistic method for quantifying uncertainty