RSM River Mechanics Podcast

When HEC hired me to add sediment transport to HEC-RAS almost 20 years ago now, I inherited a set of sediment transport functions that were mostly developed in the early to mid 20th century.  
These were – and continue to be – important equations.
But when I sat down with the RAS team 
To talk about the new science I was excited to include in a river mechanics model.
I pulled out the same binder I brought to this interview
 
We are wrapping up our third season of the podcast, and our three-part mini series on gravel bed rivers  And talking to the scientist who wrote all the papers in that binder, seems like a fitting way to wrap up both.

Dr. Peter Wilcock spent much of his career at Johns’ Hopkins, where he and his team developed the Wilcock and Crowe transport equation and did some of the most important gravel bed transport work that was hitting the journals when I was coming of age in the field.

Peter is unquestionably one of the most important contemporary contributors to quantitative gravel-bed transport science and engineering.
He won the American Society of Civil Engineers Hans Albert Einstein award in 2008 and is a fellow of the American Geophysical Union.

And we talked a lot about that fundamental, early work, that is just kind of part of established gravel bed transport theory these days.

But 10 years ago he moved to Utah State, improving his proximity to classic gravel bed rivers, and in the years since I put that binder together of his paradigm shifting work, 
Peter has been very intentional about translating his science into practical channel design methods, particularly for restoration channel designs.

So we talked about both…starting out with more of the channel design topics and then moving into his classic findings. 

The Link to Peter's Stream Assessment and Design Class Materials (including iSURF) that we talk about is here:
https://qcnr.usu.edu/wats/programs/short-courses/sediment-transport/course-materials-2022

We also talk about Ron Copeland's channel design method.  We made a short video with Ron on that method which is good background for this episode here:
https://youtu.be/ykJ3FA39p0g
Ron's podcast is here:
https://podcasts.apple.com/us/podcast/ron-copeland-on-analytical-channel-design-the-laursen/id1650989239?i=1000587444097

Finally, we also have an interview with Joanna Curran (the Crowe in Wilcock and Crowe) which makes a good companion to this episode here:
https://podcasts.apple.com/us/podcast/joanna-curran-on-gravel-bed-rivers-wilcock-and-crowe/id1650989239?i=1000589529286

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

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Dr. Power is a food web ecologist at UC Berkeley, where she leads the Power lab which has compiled careful, long term data sets in the Angelo Reserve in Northern CA.

In addition to her early work, in Panama and the Ozarks - which we touch on briefly - Dr. Power’s  multi-decadal data sets on the Eel River, have yielded remarkable findings about how food webs function in gravel bed rivers…and spoiler alert, it sometimes involves the sorts of things we tend to talk about here…like the gravel - and how it transports.

While this is a physical science podcast, I hoped to include interviews with river Ecologists from the beginning particularly ecologists who make careful observations 
at that interface of physical and biological processes. And I always hoped I could kick that emphasis off with Dr. Power.

I teach an Ecogeomorphology module in one of our classes here at HEC and I always lead that with the Eel river story she shares About 20 minutes into this episode.
That Eel river story was one of the early influences that got me interested in the ecological interactions with river mechanics processes.

I also asked Mary about a couple of Ecological models and categories, that have corollaries in geomorphology.  So we talked about disturbance, alternative stable states as well as the Box model and the Ideal Free Distribution, which are just really helpful ideas for anyone who is interested in rivers.

Dr. Power was inducted into the National Academy of Sciences in 2012.

Links: 
Serengeti Rules: 
    https://www.pbs.org/wnet/nature/serengeti-rules-dhbtnm/19906/
Disturbance and Recover of Algal Assemblage on OK Stream     
    https://www.jstor.org/stable/2425975
Resource Enhancement: Armored Catfish, Algae, and Sediment  
   https://www.jstor.org/stable/1937361

Episode Photo: Eel River

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

Dr Alain Recking has quantified gravel bed transport with just about all the tools available to our discipline.

In addition to substantial field work- Dr. Recking has done some important and influential flume experiments.

We have talked and will talk about hiding and armoring quite a bit in this podcast, because they are difficult ideas, that are hard to measure and simulate,  and critical to gravel bed processes.

But Dr. Recking’s contributions to this vertical sorting conversation destabilizes armoring theory a bit…kind of literally,

He found that in high gradient channels,  at equilibrium flows, vertical sorting doesn’t necessarily reach an equilibrium, but can be episodic, which is important because it leads to the pulsed transport processes.

And the story he tells about how he discovered this...is just kind of narrative science at its very best.

The other characteristic of Alain’s work that I think is remarkable is his a knack for pulling together immense data sets (often including substantial data from the American West) in order to pose important quantitative questions on the meta-analyses scale.

 And so we talked about how this lead to his gravel-bed flow-resistance  work and – what I consider – the most important sediment transport equation,  since the Parker/Wilcock-Crowe generation of innovation.

 We also talk about Bedload Web, where he has collected many of the measurements he used to to these analyses: https://en.bedloadweb.com/

Dr. Recking works for INRAE – The French National Research Institute of Agriculture, Food, and Environment a research consortium  focused on sustainable development in those arenas. 

This week, on the RSM River Mechanics podcast,  we talk high gradient sorting, quantitative meta-analyses with Alain Recking.

We also posted videos clips with his experiments here:  https://youtu.be/jKFlMAkD7qo

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

A couple years ago, my agency asked me to write some guidance on sediment modeling, so, I reached out to the morphological modelers I knew, and particularly the model developers who write the morphological model code other people use.

I asked them about the common failure modes they have seen and best practices they teach, and realized we had all essentially spent a decade or two, learning the same principles.
 
So when the US federal agencies held their periodic Federal interagency sediment conference (SEDHYD) last year, I invited three of the model developers I have learned from over the years (Alex Sanchez, Gary Brown, and Blair Greimann), to participate in a panel discussion on their lessons learned.

And the panel was much more popular than we expected.  It turns out, there’s appetite conversations like this.  So, I turned on the mics and we did a little editing, and we’re running it here.

Here are brief bios for our guests.:

Gary Brown did his graduate work at the university of Florida and works at the Coastal and Hydraulics Lab which is part of ERDC, the Corp’s major R&D center in Vicksburg Mississippi.   He’s been developing sediment models for 29 years including SEDLIB, a set of sediment algorithms that are called by ERDC’s hydraulic model, ADH or Adaptive hydraulics.  

Alex Sanchez sits in the office next to me.  For the last 9 years, he has worked here at HEC and spearheaded the work to add 2D sediment to HEC-RAS which includes a novel formulation for the sub-grid approach.  But actually Alex started developing sediment models at ERDC’s Coastal and Hydraulics Lab where he worked for 8 years, while working on the Coastal Modeling System which is still used for Corps of Engineers coastal applications.  

Blair Greimann got his PhD from the University of Iowa and worked at the Bureau of Reclamation’s Technical Service Center in Denver for more than 23 years, before his recent move to Stantec.  While working at the Bureau Blair led the development of SRH-1D and applied this model to a range of projects including the Matilija and and Klamath Dam removals.

Finally, we were lucky enough to have Doug Shields moderating this session so you will hear from him in the breaks between the four sub-topics.  Dr. Shields, worked for more than 20 years at the Sedimentation Lab of the Agricultural Resource Center in Oxford MS and 10 years at ERDC and has taught at both Tennessee State and Old Miss and we were fortunate to draw Doug as a moderator.  (Note: I did not mic Doug, but wanted to keep his thoughtful and winsome transitions, so his sound quality is not at the same level as the rest of the recording).

After Doug and I introduced the session you will hear from Blair Greimann, Alex Sanchez, me again, and Gary Brown in that order.

The conference paper associated with this session is here:
https://www.sedhyd.org/2023Program/1/157.pdf

Thank you to the SEDHYD organizers (including but not limited to ) for hosting this conversation

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

I’ve heard people call Tony the godfather of Sediment Transport Modeling and - as you’ll hear in our conversation - he very well may be the first person to use a computer to answer an engineering scale sediment question.

But most people about my age and older, know Tony for developing the first generalized sediment model.  He was part of the original team here at the Hydrologic Engineering Center (HEC) where he developed HEC6, a 1D sediment transport model that was industry standard for decades.

Now, if you get a couple of model developers together, we could talk all day about transport equations and algorithms.
And we did.  

But I am going to turn most of that technical modeling content, into videos to run on the YouTube page and in the RAS manual.

This conversation focuses on Tony’s insights that I think have the broadest application.

Because one of the things that make’s Tony’s career so interesting, transcends modeling.

After Tony worked at HEC, he moved to the Corp’s lab in Mississippi  and then started Mobile Boundary Hydraulics,  which was the premier 1D sediment modeling shop for decades.

But if you follow the timeline, that means that Tony (who only recently, actually, retired) has been predicting river processes for more than 60 years.
He is one of the few people who has seen the end of his 50 year project life predictions.

And all numerical modeling is – fundamentally - is exposing your mental models, to quantitative feedback and observational falsification.
It’s a learning loop with Rivers…
 …and no one has been working that learning loop longer than Tony.

I essentially sit in that seat Tony invited as the sediment modeling specialist here at HEC.  But Tony actually had a more direct influence on me than that.
About 20 years ago, when we decided to put 1D sediment transport into HEC-RAS, we got a grant to bring Tony back to HEC and he spent 5 months essentially teaching me how to develop a generalized sediment model.

There was a point in my life, where almost everything I knew about sediment came from Tony, and his insights and categories still frame the way I look at rivers.

When I first imagined this podcast, it included a conversation with Tony, reproducing some of those formative conversations we had over the years.

So in this conversation we talk about the sediment modeling origin story and some of the modeling principals he’s famous for but we also just talk about the river processes and projects that built his intuition and/or surprised him over the years.

(Photo Credit: Tony on the Arroyo Pasajero – provided by Dr. Ron Copeland) 

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

Dr. Jim Selegean is the Sediment Transport Specialist at the Corps Detroit District where he studies the rivers and sediment loads into the great lakes as well as inland costal processes.

 He is also a professor at Wayne State in Detroit. And that joint position has helped him mentor many young scientists and engineers  throughout the years, geomorphically trained Hydraulic engineers who not only currently populate the Detroit district but also includes what we call the Detroit diaspora,  Jim’s protégées who fill important sediment and river mechanics leadership positions across the Corps.

 We recorded this podcast in the lab and field investigation shop  Jim built on the Detroit River, which is the most complete and productive corps sediment lab I know of outside Mississippi. 

 Within my agency, I don’t know anyone who has quite the grasp of the river mechanics cannon, as Dr. Jim Selegean of the Corps of Engineers’ Detroit District.

 But he also metabolizes as much contemporary literature as anyone I know in our agency, which manifests in a weekly email he sends out, with the 8-10 best papers he read from current journals that week and a 3-4 sentence summary of his favorites.

 (If you’d like to get on that list, you can reach out to him at [email protected])

 One of the things I found helpful in my Ecology education was a Foundations of Ecology text (https://a.co/d/9zjK1wg) which compiled the classic papers in ecology and commentaries by noted contemporary scientists whose work built on that particular area of reflection.

 Years ago I pitched this type of book to Jim, suggesting we should try to write it of our field.

 He just laughed at me, wisely predicting that neither of us nearly the time required.

But when I stared to design this podcast, I knew I wanted to recording a kind of “pitch meeting” for the papers we would each include in that compilation.

 But, Jim is also one of the most fun people I work so we tried to make it a little more entertaining…and a little competitive, by giving it a draft format (like picking players for a schoolyard football game).

 There was some strategy…that mostly went Jim’s way.

 Feel free to find the posts associated with this podcast on LinkedIn or X to offer your choices…maybe we’ll do another one.

 But for now, welcome, to the RSM River Mechanics Podcast…Classic Paper Draft.

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

Dr. Astrid Blom is a professor Civil Engineering & Geosciences at Delft University of Technology in the Netherlands is perhaps best known for her recent reach and rive scale work, modeling hundreds of kilometers, sometimes for hundreds or thousands of years.  These models explore the long-term equilibrium state of river responses to human modifications and the alternate potential futures associated with different climate change scenarios and management practices.

 Most of her recent work and, as you’ll here in our conversation - the work she is most passionate about – is that actionable – morphological modeling of the Dutch reach of the Rhine that can influence wise and sustainable management.

 And I’ve been interested in Dr. Blom’s work on the Rhine for a while, partially because of its similarity to the Missouri in the US – which is a river of comparable size with comparable human modifications, which is also incising. 

 But I first started following Dr. Blom’s research over 15 years ago – with work she did at the particle scale – with detailed laboratory work on the vertical mixing processes in bedforms composed of a wide range of grain sizes.

So we talked about both of these scales.  

 We mostly talked about the Rhine, because the river’s natural template, the long history of human modification, the reach scale incision, and contemporary management efforts on that system are so interesting.  

 And we covered some fundamental processes at that scale, including how gravel-sand transitions evolve on engineering and geologic time horizons on a river that size, the impacts of incision on a large, multi-use, waterway, and some of the management practices targeted to mitigate these impacts.

 But we also downscaled a little to talk about her early lab work…because it really has affected the way I look at bimodal rivers and gravel-sand transitions.

Links to Dr. Blom's papers are on the podcast website (link below).

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

In the previous episode, we talked to Dr. Marcelo Garcia about the astonishing compilation of sediment science he edited, the ASCE Sedimentation Manual.   

In this episode, we turn to some of his work, covering a wide range of topics, but landing for a while on sedimentation hazards including mud and debris flows, the Bulle Effect, and two transport paradigms (the Bagnold vs the Einstein approaches).  

Dr. Garcia is professor at the University of Illinois-Urbana and the director of the Ven Te Chow hydraulic lab.  

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

Dr. Marcelo Garcia holds an endowed chair in Hydraulics at the University of Illinois-Urbana – where he has taught for more than thirty years, and runs the remarkable Ven Te Chow hydraulic and sediment laboratory. 

His award page reads like a who’s-who of the Legends in our field.  
These include but are not limited to:
The Einstein Award, 
the Rouse Award, 
and the Yalin lifetime achievement award.

And he is a Distinguished member of the American Society of Civil Engineers and the an elected fellow of the American Geophysical Union.

And that’s all very impressive.  Dr. Garcia is - without question – one of the leading quantitative sediment scientists of his generation.

But the quality that made this conversation remarkable, is Marcello’s grasp and deep connection with the history of the sediment transport and river mechanics disciplines.

It became clear that he sees his work in continuity with the foundational work and scientists that preceded him.  He has effortlessly describes how modern sediment transport principles or puzzles are rooted in the work and lives of our discipline’s historic figures.

And, well, these are some of the big themes I hoped for with this podcast.

This is also why he was uniquely qualified to the 10-year project of compiling the American Society of Civil Engineers Manual of Practice on Sedimentation (110) – arguably the most comprehensive work on sediment science and engineering available. 

We talked about that project, how he collaborated with dozens of authors to knit together this massive compendium of sediment and river insight.  But in the process, I learned a lot, not only about some of the big ideas in our disciplines, but also the stories of the people behind them and how they became some of our big ideas.

The ASCE Manual of Practice is here: https://ascelibrary.org/doi/10.1061/40856%28200%2994

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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

Dr. David Montgomery has been so prolific, that for several years I actually thought he was two people:

First, Dr. D. Montgomery is a well known geomorphologist from the University of Washington (and a 2008 MacArthur Fellow) whose name is on much of the seminal, high-gradient channel transport and classification literature.

 And then there David Montgomery,  the narrative non-fiction author from Seattle who wrote books like Dirt, The Rocks Don’t Lie, and The Hidden Half of Nature.

It actually took me an embarrassing amount of time to realize that this was the same person.

So the first time I sat down to scribble a list of guests I’d like to invite on a yet to be named river process podcast, Dr. David Montgomery was on that first list…because who wouldn’t want to talk to both those people...especially at the same time.

In this conversation David and I moved between the spatial and temporal scales his work spans,  discussing the deep sediment history from his books and his classical technical work.

 We cover the role of sediment in the rise and fall of ancient near-eastern civilizations, high-gradient river classification, a surprising story about the long temporal tail of wood impacts in natural river systems, incipient motion at the grain scale, and, somehow, a range of other topics.

 And, I found out that there is, actually, a third David Montgomery…guitar and vocals for the Seattle band Big Dirt, so most of the music you’ll hear (after the opening theme) is from their new album. 


You can find David's books that we talked about here:
Dirt - https://a.co/d/eaE9P3Y
The King of Fish - https://a.co/d/2wArLH1
The Hidden Half of Nature - https://a.co/d/1ZIU9Tb
What Your Food Ate - https://a.co/d/9Qtt0dX

And you can access music from Big Dirt here:
https://open.spotify.com/artist/6CAz9l0qkiWwLlaVHC1Xrm

This series was funded by the Regional Sediment Management (RSM) program.

Stanford Gibson (HEC Sediment Specialist) hosts.

Mike Loretto edited the episode and wrote and performed the music.

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