Hydro Research Foundation Fellows
Quantifying streambed scour – deposition below hydropower dams using temperature time series data, Tim DeWeese
Tim’s research aims to develop a new, simple and economical method to continuously monitor and record local streambed scours and depositions for ecological and engineering purposes. The method uses naturally occurring daily temperature oscillations in stream water as a signal to detect changes in streambed elevation. His laboratory experiment uses a sediment tank to mimic stream water temperature oscillations and groundwater flux. Quantification of bed elevation changes in the sediment tank are predicted and compared to actual imposed values. Tim is also working on a field temperature probe prototype that he will place downstream of a dam release controlled river and use to demonstrate streambed elevation changes related to dam release flow regime.
Improving on hydropower mitigation success by refining predictions of grain motion,
Heidi's research aims to improve on predictions of the onset of sediment motion in rivers by including the effects of turbulence and local river topography. Current motion predictions result in large errors so improving them will aid in our ability to predict sediment loads more accurately and restore rivers more effectively. To build her numerical model, Heidi collected turbulence data using the Center for Ecohydraulic's flume laboratory. Then, in Brunni Switzerland, she tested her sediment motion model in an outdoor river laboratory administered by the Swiss Federal Institute for Forest, Snow and Landscape Research.
The Center for Ecohydraulics Research and the University of Idaho are grateful to the Hydro Research Foundation for their generous support of Tim DeWeese and Heidi Smith.