How Hydrologic and Geomorphological Processes in Gravel-Bed Rivers Sustain Chinook Salmon Spawning Habitat During Managed Flow Regimes

R/SF-59
Start/End: October, 2013 to September, 2015

Chinook salmon begin and end their lives in the gravel-bottomed upland reaches of rivers, and it is believed that suitable habitat for salmon eggs occurs along stretches of gravel with good groundwater and surface-water exchange. A main goal of this project is to figure out how to predict the locations of where this exchange occurs. To do this, the fellow will study the effects of stream-flow releases and sediment characteristics on flows between river channels and groundwater aquifers. Among the questions that will be addressed in the projects early stages are: How does the geometry of gravel bars vary between natural, flow-altered and engineered gravel bars? What are the hydrologic implications of the observed geometry of gravel bars? And, what is the form and function of bend-bar morphology in terms of infiltration and seepage patterns, as it relates to suitable salmon spawning habitat? Findings are of relevance to identifying ways to restore spawning habitat for Chinook salmon through actions, such as gravel augmentation and altered managed flows.

Research mentor: Thomas Dunne, UC Santa Barbara

Community mentor: Erin Rice, U.S. Bureau of Reclamation

  • University of California, Santa Barbara (UCSB)