Collaborative Research: Shifting Snow, Changing Flow--Quantifying Warming-Induced Seasonal Streamflow Changes in the Snow-Fed Columbia River over the Past 500 Years

Accumulation of snowpack and the timing of the melt in the mountains that feed the Columbia River Basin change both the timing of spring flood risks and the risk of drought in summer and fall. These changes in streamflow impact ecosystems, including salmon migration and reproduction, and challenge water management for agriculture and the property and livelihoods of populations in the Basin. Information about the range of streamflow variability and changes through time are valuable for water management. There are existing reconstructions of annual streamflow for the Columbia River Basin based on tree rings. However these annual records do not contain information about seasonal-scale or shorter variations in streamflow. This project will use a novel combination of existing statistical and modeling techniques and measurements of previously-collected archives of tree rings to reconstruct daily streamflow from the past. The project will support one postdoc and two graduate students. In partnership with Futurum Careers, the project will create teaching materials for educators, create other educational materials K-12 and college students, and conduct other public outreach efforts. The goal of the project is to use existing tree-ring collections from the Pacific Northwest to measure blue intensity in order to reconstruct spring and summer precipitation and temperature for the Columbia River Basin for the last 500 years. The project will statistically disaggregate the seasonal precipitation and temperature reconstructions into daily values then use a distributed water balance model to produce daily streamflow reconstruction. The project will support one postdoc and two graduate students. In partnership with Futurum Careers, the project will create teaching materials for educators, create other educational materials K-12 and college students, and conduct other public outreach efforts. 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.