Collaborative Research: Sediment fluxes in boreal rivers: determining relative seasonal loads and expanding long-term monitoring capability

Oregon State University, Corvallis OR

Investigators

Abstract

Sediments are transported by rivers to global oceans where they help form coastal landforms including beaches, deltas, and marshes. The amount of sediment discharged by rivers annually has been measured for numerous rivers worldwide, but data for Arctic river sediment loads remains sparse largely due to inaccessibility during winter and the springtime “breakup” season (when large blocks of ice fail and move downstream, typically in conjunction with high river flow). The research community is also challenged by the costs of sensors, which are too valuable to deploy in large numbers or during risky ice-covered and breakup seasons. The research will engage local Alaska Native school students in the data collection for the project and supports early career women and students. In this project, a recently developed “do-it-yourself” optical backscatter sensor will be leveraged in order to make improved measurements of Arctic fluvial sediment fluxes. These sensors can be built for less than 10% of the cost of commercial sensors, and in this project they will be expanded to include data logging and power that is separate from the sensor, as well as satellite-enabled data transmission. These developments will allow sensor deployments in summer, fall, and winter seasons on the Tanana River near Fairbanks, AK in order to constrain sediment concentrations in three seasons. Drone-based deployments will be conducted during spring breakup to complete the four seasons of measurements. Deployments will be complemented by surveys of river velocity and modeling of fluvial sediment transport in order to better understand annual sediment loads. The ultimate aim is to provide a tool for fluvial sediment measurements across the Arctic (and beyond). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.