David Topping on the Grand Canyon Prototype Experiments, Disequilibrium Transport, and Hysteresis

Dr. David Topping is a Research Hydrologist with the US Geological Survey. He did his undergrad at MIT, a masters and Phd at the University of Washington and has published >100 well cited peer review publications.  Dr Topping  has worked with the USGS for >30 years but for the last 18 or so have been with the Grand Canyon Monitoring and Research Center in Flagstaff AZ where he has been one of the reasons that the Glen Canyon releases have become in one of the most ambitious and carefully measured protype sediment experiments in history.  And it is his teams extensive and precise measurements of these experiments and thoughtful analyses of those data that echoed through multiple aspects of my work in the years that followed.  I went back to the papers we talk about in this episode several times… …when I was working on bed mixing algorithms in HEC-RAS …and when I was working with the Corps’ Omaha district to restore sand bars on the Missouri river  …and when I was interpreting sediment time series, from the main Amazon tributaries… I kept finding myself back in his literature.  His team’s work on processes that build and erode sand bars, his distinction between flow regulated and bed regulated transport, and his careful identification of the time scales and grain sizes at play when we think about ‘supply limitation’ and disequilibrium transport have all made their way into my work and my mental model of rivers. You can find more of his work at these links: https://www.usgs.gov/staff-profiles/david-j-topping https://www.usgs.gov/centers/southwest-biological-science-center/science/river-sediment-dynamics https://www.gcmrc.gov/discharge_qw_sediment/ This series was funded by the Regional Sediment Management (RSM) program. Mike Loretto edited the first three seasons and created the theme music. Tessa Hall is editing most of Season 4. Stanford Gibson (HEC Sediment Specialist) hosts. Video shorts and other bonus content are available at the podcast website: https://www.hec.usace.army.mil/confluence/rasdocs/rastraining/latest/the-rsm-river-mechanics-podcast ...but most of the supplementary videos are available on the HEC Sediment YouTube channel: https://www.youtube.com/user/stanfordgibson If you have guest recommendations or feedback you can reach out to me on LinkedIn or ResearchGate or fill out this recommendation and feedback form: https://forms.gle/wWJLVSEYe7S8Cd248