Stanford Gibson
Stanford Gibson
  • Видео 97
  • Просмотров 339 557
Floodplain Deposition Approachs in HEC-RAS 6.6 (coming soon)
Floodplain deposition can be challenging in a 1D morphodynamic model. In this video we discuss some of the classic and new approaches in HEC-RAS to compute 1D floodplain deposition.
Documentation and Data Set:
www.hec.usace.army.mil/confluence/rasdocs/rassed1d/1d-sediment-transport-user-s-manual/entering-and-editing-sediment-data/sediment-properties-options/bed-change-options/floodplain-deposition-methods
Просмотров: 1 091

Видео

Estimating Non-Newtonian Parameters for HEC-RAS Models
Просмотров 8712 месяца назад
This is a talk from the HEC Post Wildfire class we taught in early 2022. I got a lot of help and insight on this from Kellie Jemes who built the majority of the early USACE mud and debris models. The class was funded by the MMC CWMS National Implementation Plan, and the video was funded by the HH&C SET program
Channel Evolution and Degradation on Duncan Creek and Bayou Pierre (feat. David Biedenharn)
Просмотров 4902 месяца назад
In this "streamside chat" Dr. David Biedenharn walks us through Duncan Creek and Bayou Pierre, Mississippi Tributaries that are actively incising. He describes the various stages of the channel evolution model we encounter and the diagnostic features of a channel responding to system-wide degradation.
Bed Sampling Considerations in an Incised Clay Channel (ft. Dr. David Biedenharn)
Просмотров 1933 месяца назад
Sometimes the sediment on the channel bed at low flow does not characterize the bed material or the channel geometry during an event. Dr. David Biedenharn from the US Army Corps of Engineers describes his method for exploring the thickness of cohesionless bed sediment in clay streams and implications of these thicknesses for geomorphic assessments and modeling.
Hans Albert Einstein Award Address (2024 - Stanford Gibson)
Просмотров 1 тыс.4 месяца назад
I won the Hans Albert Einstein award this year, which is the American Society of Civil Engineers' award for contributions to Sediment and Erosion. This is the "Einstein Lecture" from the EWRI congress (in Milwaukee May 2024) that I presented when I accepted the award. The list of previous Einstein award winners is here: www.asce.org/career-growth/awards-and-honors/hans-albert-einstein-award/han...
HEC RAS Debris Flow Speed Run
Просмотров 1,5 тыс.4 месяца назад
How long does it take to build an HEC-RAS debris flow model. How about under 12 minutes. In this video I leverage a theme from the video game youtubes and ask the question "how quickly can I stand up a simplified mud and debris, post wildfire model to get a hazard map in HEC-RAS starting with only the USGS hazard map web site (and an estimate of peak flow)?" Because I work through this pretty q...
Vertical Sorting Processes ft. Dr. Alain Recking
Просмотров 3796 месяцев назад
This is an excerpt from the RSM River Mechanics Podcast. The full interview is available here: podcasts.apple.com/us/podcast/rsm-river-mechanics-podcast/id1650989239 and other videos and interviews are available on the podcast website: www.hec.usace.army.mil/confluence/rasdocs/rastraining/latest/the-rsm-river-mechanics-podcast Bacchi, V. Recking, R., Eckert, N., Pilton, G. & Naaim, (2014) "The ...
The Exner Equation (ft Tony Thomas) Computing Sediment Continuity
Просмотров 6577 месяцев назад
HEC-RAS uses the version of the Exner (sediment continuity) equation in 1D that Tony Thomas developed for HEC 6 and 6T. In this found footage from his first ever HEC6 class (1976), Tony explains this fundamental equation behind the fundamental approach we use to simulate sediment transport. For a contemporary conversation with Tony about the early days of sediment transport modeling and the thi...
Compound Sediment Boundary Conditions in HEC-RAS (New in Version 6.5)
Просмотров 5368 месяцев назад
Rating curves can be excellent boundary conditions for suspended and wash load but modelers rarely have data for bed load rating curves. Alternately, equilibrium load can estimate bed load and even some bed material load in the absence of data, but performs very poorly with finer grain classes and wash load. So modelers would often like to use a rating curve for some grain classes and equilibri...
Iruya Debris Flows (ft. Dr. Marcelo Garcia)
Просмотров 5208 месяцев назад
We talked to Dr. Marcelo Garcia in episodes 3.2 and 3.3 of the podcast. podcasts.apple.com/us/podcast/rsm-river-mechanics-podcast/id1650989239 In episode 3.3. he talked about his work on "Sedimentation Hazards" including descriptions of a periodic debris flow in Iruya. podcasts.apple.com/us/podcast/marcello-garcia-part-2-on-sedimentation-hazards-the/id1650989239?i=1000643029954 He also provided...
Reservoir Sediment Managment Options ft. Dr. George Annandale
Просмотров 5439 месяцев назад
Dr. George Annandale provides a brief overview of some of the options available to manage reservoir sediment. This is an excerpt from Episode 2:1 of the RSM River Mechanics Podcast. You can find the full interview with Dr. George Annandale here: podcasts.apple.com/us/podcast/george-annandale-on-the-reservoir-sedimentation/id1650989239?i=1000622609844 More conversations and videos on reservoir s...
HEC-RAS "Capacity Only" 2D Sediment Modeling Demo
Просмотров 2,3 тыс.11 месяцев назад
HEC-RAS "Capacity Only" 2D Sediment Modeling Demo
Adding an Internal Structure to a 2D Mesh in HEC-RAS
Просмотров 10 тыс.11 месяцев назад
Adding an Internal Structure to a 2D Mesh in HEC-RAS
Simplified 2D Sediment Modeling with HEC-RAS ("Capacity Only" and "Concentration Only" Modes)
Просмотров 4,5 тыс.Год назад
Simplified 2D Sediment Modeling with HEC-RAS ("Capacity Only" and "Concentration Only" Modes)
Spencer Drawdown Reservoir Sediment Flush (Abbreviated Version)
Просмотров 12 тыс.Год назад
Spencer Drawdown Reservoir Sediment Flush (Abbreviated Version)
Reservoir Sediment Modeling with HEC-RAS: (Part 3) Reservoir Modeling Demo
Просмотров 1,9 тыс.Год назад
Reservoir Sediment Modeling with HEC-RAS: (Part 3) Reservoir Modeling Demo
River Mechanics Podcast Season 2 Trailer (Audio Only)
Просмотров 142Год назад
River Mechanics Podcast Season 2 Trailer (Audio Only)
Ecuador Travel Video: Galapagos and Ecuadorian Amazon
Просмотров 253Год назад
Ecuador Travel Video: Galapagos and Ecuadorian Amazon
Calibrating a 2D HEC-RAS Model with ADCP Transects
Просмотров 2,8 тыс.Год назад
Calibrating a 2D HEC-RAS Model with ADCP Transects
How to Copy Mods Between HEC-RAS Terrains (unexpected steps and big file hacks)
Просмотров 1,4 тыс.Год назад
How to Copy Mods Between HEC-RAS Terrains (unexpected steps and big file hacks)
Computing Annual Sediment Load and LOESS with HEC-RAS (in v6.4)
Просмотров 846Год назад
Computing Annual Sediment Load and LOESS with HEC-RAS (in v6.4)
Add Observed Data to HEC-RAS 2D/Mapper
Просмотров 4,2 тыс.Год назад
Add Observed Data to HEC-RAS 2D/Mapper
Importing USGS Terrain Directly into HEC-RAS Mapper
Просмотров 8 тыс.Год назад
Importing USGS Terrain Directly into HEC-RAS Mapper
Lahars (ft. Dr. Richard Iverson)
Просмотров 658Год назад
Lahars (ft. Dr. Richard Iverson)
The Rio Coca Regressive Erosion (ft. Pablo Espinoza Giron and Pedro David Barrera Crespo)
Просмотров 1,7 тыс.Год назад
The Rio Coca Regressive Erosion (ft. Pablo Espinoza Giron and Pedro David Barrera Crespo)
Insights from the USGS Debris Flow Flume (ft. Dr. Richard Iverson)
Просмотров 1,6 тыс.Год назад
Insights from the USGS Debris Flow Flume (ft. Dr. Richard Iverson)
The Mount Saint Helens Sediment Retention Structure (ft Chris Nygaard)
Просмотров 887Год назад
The Mount Saint Helens Sediment Retention Structure (ft Chris Nygaard)
Missouri River Management and Sediment (ft. John Remus)
Просмотров 570Год назад
Missouri River Management and Sediment (ft. John Remus)
Step-Pool Spacing, Formation, and Experiments (ft. Dr Joanna Curran)
Просмотров 1,2 тыс.Год назад
Step-Pool Spacing, Formation, and Experiments (ft. Dr Joanna Curran)
The Copeland Analytical Channel Design Approach (ft. Dr. Ron Copeland) (07Dec2022 repost)
Просмотров 484Год назад
The Copeland Analytical Channel Design Approach (ft. Dr. Ron Copeland) (07Dec2022 repost)

Комментарии

  • @renaldyandrean
    @renaldyandrean 3 дня назад

    With how you mention sediments moving through gates, is it now possible to simulate flushing?

    • @stanfordgibson
      @stanfordgibson 2 дня назад

      I do 1D flushing models pretty often these days. We make some assumptions...but I've gotten pretty good results. erdc-library.erdc.dren.mil/items/67f7122c-5c68-4df8-b669-d9d7ca1bd6da

  • @leeadams5816
    @leeadams5816 11 дней назад

    Hi Sanford. Very helpful modeling approach you demonstrate here. I am interested in what you might think of this approach. It was challenging to get the cells in the refinement regions lined up so perfectly with the pier terrain modification. I kept seeing leakage at the piers, so I did the following: Place the piers in the model at just a tenth or two smaller than they really are. Establish the Refinement Regions by tracing over the pier modifications, mesh the model, edit the Computational Points as needed. Then, return to the pier terrain modification editor and edit the pier width to the real, slightly wider width. I'm hoping that the result will be that the Terrain is modified for the pier and it will widen into the adjacent cell, effectively blocking that side of the cell and preventing flow from "leaking" through it.

    • @stanfordgibson
      @stanfordgibson 10 дней назад

      Sounds good to me!

    • @stanfordgibson
      @stanfordgibson 10 дней назад

      Also, RAS2025 already includes gaps, so it will be much easier in the new version.

  • @nanandongotehua
    @nanandongotehua 14 дней назад

    hello trainer. I would like to know how to make the scale appear at the bottom of the map on HECRAS!???

    • @stanfordgibson
      @stanfordgibson 6 дней назад

      This can be confusing. The scale only shows up if you select the output node on the tree. For example, you can be plotting velocity whether you have selected the node or not if it is checked. But to see the legend and scale you have to select it.

  • @santicata89
    @santicata89 15 дней назад

    Congrats Stanford. Your mission to balance science and consultancy is an honor. Climate change is bringing more disequilibrium making your mission an urgent one. So: what a footprint you are leaving!

  • @prashantmaidase8806
    @prashantmaidase8806 16 дней назад

    Ras mapper tab not open

  • @santicata89
    @santicata89 16 дней назад

    thanks to professor Recking for his worthy advices along my doctoral dissertation. I wonder if HecRas would consider including his friction and sediment transport equations, which I have coded for fluvial morphodynamics, because they are numerically manageable while highly robust in a large range of scales/contexts for mountain rivers.

    • @stanfordgibson
      @stanfordgibson 16 дней назад

      We haven't used his transport function in the past because it was not partitioned by grain class (which RAS requires). But Alain mentioned that he has a version that is partitioned by grain class headed to the journals. We will definitely consider it when we add sediment to 2025.

    • @santicata89
      @santicata89 16 дней назад

      @@stanfordgibson thanks for your reply. I used his partition approach, as the paper in which he describes it gives some intuitive criteria to choose values for the partition parameters. They provide a lot of flexibility, I think that more than other typical partitions like W&C2003 approach. That way one obtains selective transport and bed coarsening at base flows (recessions), and transport of most grain classes at floods. What this implies for flow friction will depend strongly on active layer thickness, which is indeed a concept to be taken with care due to vertical sorting.

  • @vincelee4684
    @vincelee4684 24 дня назад

    thank you so much 🎉 May I know is there any updates on BSTEM?

    • @stanfordgibson
      @stanfordgibson 6 дней назад

      Sorry, no. We did find a bug. I'll get it fixed in 6.7

    • @vincelee4684
      @vincelee4684 6 дней назад

      @@stanfordgibsonlooking forward to see more enhancements on it!!

  • @hamidrezafazeli2650
    @hamidrezafazeli2650 29 дней назад

    thanks..since i am doing erosion study due to bed mining, your uploaded videos are very helpful, helps me better digest the sediment analysis process

    • @stanfordgibson
      @stanfordgibson 6 дней назад

      Thanks. We've used ras for bed mining studies too. I have a "dredging" video from a long time ago that might help.

  • @glauberdepaula7940
    @glauberdepaula7940 Месяц назад

    Hi, thanks for sharing your knowledge! Is in the plans of the HEC team to implemente the ability to run a varied Cv for non-newtonian simulations like in FLO-2D?

  • @gianlucagottardi7434
    @gianlucagottardi7434 Месяц назад

    It is possible to have more details about the example presented as: Sudden Expansion Lab Experiment ? I recreated the model with HEC-RAS 2D, but I don't understand whether the image presented at min 4:00 is a view from above of half the channel or of the entire channel. I modeled with HEC-RAS as in the image, but vortices are also formed on the upper wall, and the speed trend does not correspond to that presented with both conservative and non-conservative turbulence models.

    • @stanfordgibson
      @stanfordgibson 6 дней назад

      We included the Weis data set with the 6.6 release and are going to be posting the full 2D sediment class with videos in the coming year.

  • @ryancusack8168
    @ryancusack8168 Месяц назад

    Thanks for this video, very helpful. I am having a similar issue with a model i created. It's a rectangular spillway in which the water drops down feeding directly into a large culvert. The stability after the water drops from the spillway and into the culvert spikes and causes a the model to work incorrectly. Any help/recommendations for this issue would be greatly appreciated!

  • @edwinamaya6334
    @edwinamaya6334 Месяц назад

    Thank you, excellent tutorial. I have a question: how can I estimate my CV through HMS? and what information would you need to feed that model? Thank you

  • @edwinamaya6334
    @edwinamaya6334 Месяц назад

    Excellent presentation, you really contribute a lot with your knowledge, especially to countries where these issues are not deepened. I have a question for you, when the fluid is dilating, that is, there is an internal collision of the particles and that large blocks float on this fluid and are transported. What kind of non-Newtonian flow model of Hecras could I implement to simulate it? Thank you

  • @daudkiputa3887
    @daudkiputa3887 Месяц назад

    Very helpful video. Thank you for sharing this

  • @Will-cv7ws
    @Will-cv7ws Месяц назад

    Cool and very useful functionality. Thank-you for sharing. NOTE: The only way I was able to get it to run in v6.5 was to make the inflow boundary an external condition.

    • @stanfordgibson
      @stanfordgibson Месяц назад

      Yes, that's right. Internal flow boundary conditions do not work with sediment. And since we added internal flow boundary conditions, older models that defined the the boundary condition within the mesh read as internal bcs.

  • @rahmadeenk3362
    @rahmadeenk3362 2 месяца назад

    Dear Prof. Gibson, I've trouble and error : Unsteady Input Summary: 2D Unsteady Diffusion Wave Equation Set (fastest) 2D number of Solver Cores: 12 HDF_ERROR trying to use HDF output file Subroutine HDF_SET_COMPRESSION HDF_ERROR trying to close HDF output file: HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0: #000: ..\..\src\H5Pdcpl.c line 869 in H5Pset_chunk(): all chunk dimensions must be less than 2^32 major: Invalid arguments to routine minor: Out of range Error starting unsteady simulation - Stopping compute process What is the solution for this case, Thanks before

  • @hossein1063
    @hossein1063 2 месяца назад

    Thanks for sharing. I do not know why does not work for me.

  • @ghelaimiabdallah9667
    @ghelaimiabdallah9667 2 месяца назад

    hello, How can I validate an HEC-RAS model if the observed water heights are twice as high as those simulated for a centennial flood?

    • @stanfordgibson
      @stanfordgibson 2 месяца назад

      I'm afraid that sounds like a data issue...either with the flows or the high water marks. Unless you are loosing water through your mesh.

  • @ghelaimiabdallah9667
    @ghelaimiabdallah9667 2 месяца назад

    hi, How can I validate an HEC-RAS model if the observed water heights are twice as high as those simulated for a centennial flood?

  • @amt19696
    @amt19696 2 месяца назад

    Thank you for your comprehensive explanation.

  • @johnsamuels6021
    @johnsamuels6021 2 месяца назад

    Silted in MUCH??!!

  • @razinahmad1533
    @razinahmad1533 2 месяца назад

    can they be used to calculate the Volume of deposits of sediment ???

    • @stanfordgibson
      @stanfordgibson 2 месяца назад

      Yeah, that was the main intent of this feature.

  • @jonathanproano5035
    @jonathanproano5035 2 месяца назад

    hello, someone knows about this error? HDF5-DIAG: Error detected in HDF5 (1.10.6) thread 10344: #000: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5F.c line 444 in H5Fcreate(): unable to create file major: File accessibilty minor: Unable to open file #001: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5Fint.c line 1509 in H5F_open(): unable to open file: time = Fri Jul 26 13:34:22 2024 , name = 'C:\Users\Jonathan Proaño\AppData\Local\Temp\76d7fabd-71ac-4f5e-b4e4-097452e2a832.h5', tent_flags = 13 major: File accessibilty minor: Unable to open file #002: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5FD.c line 734 in H5FD_open(): open failed major: Virtual File Layer minor: Unable to initialize object #003: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5FDsec2.c line 346 in H5FD_sec2_open(): unable to open file: name = 'C:\Users\Jonathan Proaño\AppData\Local\Temp\76d7fabd-71ac-4f5e-b4e4-097452e2a832.h5', errno = 2, error message = 'No such file or directory', flags = 13, o_flags = 302 major: File accessibilty minor: Unable to open file

    • @stanfordgibson
      @stanfordgibson 2 месяца назад

      If you get an error like that, it is a bug. Even if it is user error, we should provide more informative error messages. You can send a bug report and a link to your modle to the RAS inbox for this one.

  • @jonathanproano5035
    @jonathanproano5035 2 месяца назад

    someone knows about this error? HDF5-DIAG: Error detected in HDF5 (1.10.6) thread 10344: #000: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5F.c line 444 in H5Fcreate(): unable to create file major: File accessibilty minor: Unable to open file #001: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5Fint.c line 1509 in H5F_open(): unable to open file: time = Fri Jul 26 13:34:22 2024 , name = 'C:\Users\Jonathan Proaño\AppData\Local\Temp\76d7fabd-71ac-4f5e-b4e4-097452e2a832.h5', tent_flags = 13 major: File accessibilty minor: Unable to open file #002: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5FD.c line 734 in H5FD_open(): open failed major: Virtual File Layer minor: Unable to initialize object #003: D:\build\HDF5\1.10.6\hdf5-1.10.6\src\H5FDsec2.c line 346 in H5FD_sec2_open(): unable to open file: name = 'C:\Users\Jonathan Proaño\AppData\Local\Temp\76d7fabd-71ac-4f5e-b4e4-097452e2a832.h5', errno = 2, error message = 'No such file or directory', flags = 13, o_flags = 302 major: File accessibilty minor: Unable to open file

  • @nurulnaqilazns
    @nurulnaqilazns 3 месяца назад

    Hi Dr. Gibson, when I run my model, this error messages popup. I checked all my input data - flow duration and computation increment, all data is more than 0. Can help to clarify why this error keeps happening? Sediment Transport Analysis HEC-RAS 6.x An error occurred with sediment boundary data. The Boundary duration data and Computation Increment Must both be greater than 0.0 Please check your data.

    • @stanfordgibson
      @stanfordgibson 2 месяца назад

      There are several issues that can cause this...I list them here: www.hec.usace.army.mil/confluence/rasdocs/rassed1d/1d-sediment-transport-user-s-manual/trouble-shooting/common-sediment-transport-error-messages

  • @richman1905
    @richman1905 3 месяца назад

    Why go through the hustle of log-transforming the data and using a complicated equation to avoid a transformation bias? Why don't people fit a non-linear model in euclidian space from the get-go? Is it just that log-sapce is better for visualization or is it a historic thing?

  • @vctr196
    @vctr196 3 месяца назад

    Thank you for the video. When you copied the coordinates into the barrel GIS data, did that change the length of the culvert?

    • @stanfordgibson
      @stanfordgibson 3 месяца назад

      Good question. No...it did not. This is an important point. The culvert length stays the same that you specified...the coordinates just determine the headwater and tailwater elevations/cells.

  • @whiskerbiscuit99
    @whiskerbiscuit99 3 месяца назад

    This dam failed in 19

  • @DrewAlexandros
    @DrewAlexandros 3 месяца назад

    Very cool! This reminds me of how different periods of freezing/thawing (as well as many other processes) create distinct layers of snow and ice crystals over a snow slope - which can be responsible for avalanches.

  • @razinahmad1533
    @razinahmad1533 3 месяца назад

    These Podcasts are really cool, the excerpts with additional complemenary data/videos/graphics makes it super interesting. One thing I would like to see added, is the option of having video format for the whole podcast like Joe Rogan does IT just gives a nice feel to it, Morevoer, these images can be shown in real time, during the podcast with some help ofcourse, Furthermore, these edits can still be continued after the podcasts.

    • @stanfordgibson
      @stanfordgibson 3 месяца назад

      For sure...that would be great...but the editing time would preclude any new sediment features in RAS for the foreseeable future. :)

  • @jwiest
    @jwiest 3 месяца назад

    Congratulations Stan! Great acceptance speech!

  • @dianalucina
    @dianalucina 3 месяца назад

    I love you!! Thank you much.....

  • @hamedtagizadeh
    @hamedtagizadeh 3 месяца назад

    Well deserved

  • @PraviRus
    @PraviRus 3 месяца назад

    Bro, you just found fresh Troll dung!! 😅

    • @stanfordgibson
      @stanfordgibson 3 месяца назад

      Hahaha...for sure. I update my hypothesis.

  • @51toniz
    @51toniz 3 месяца назад

    It's so much fun to see a former student! I always wonder what the "kids" are doing with their lives. Congratulations, Stan. Well deserved recognition.

  • @51toniz
    @51toniz 3 месяца назад

    BRAVO!!!

  • @AbirGANGULY-g7h
    @AbirGANGULY-g7h 4 месяца назад

    Too good to give thanks......but still thank you so much sir❤

  • @Useitorloseit1
    @Useitorloseit1 4 месяца назад

    Model of How the Grand Canyon was made.

  • @JeffreyDegraff
    @JeffreyDegraff 4 месяца назад

    Congrats!!! And thank you for the general tip about using "Rules" for gate controls. I just used it in a Debris Model by assuming the bridge will clog when approximately half amount of material passes through the bridge opening.

    • @stanfordgibson
      @stanfordgibson 4 месяца назад

      Excellent! Very creative. I have done something very similar. We often make blanket assumptions about bridge clogging (e.g. all bridges will clog 50 or 80% except freeways) in debris flow. But clogging them from the start can mess with arrival times (flooding arrives too early). So using a gate to "clog" a "bridge" is a great way to get the best of both worlds.

  • @konefadjiguiabdoulaye8921
    @konefadjiguiabdoulaye8921 4 месяца назад

    Thank you very much for this very useful video, from Cote d'Ivoire (Ivory Coast)

  • @LB7EJ_Bjorn_Otto
    @LB7EJ_Bjorn_Otto 4 месяца назад

    Congratulations!🎉🎉🎉🎉

  • @TheBalticSun
    @TheBalticSun 4 месяца назад

    Very useful, thanks for the lesson! I'm working with this Bingham model in my master thesis. I have a question about the non newtonian Cv parameter: If I set the Cv = 60% and select the "Do Not Bulk" option, then the simulation doesn't take into account the volume concentration? Or is it actually taken into account but its assumed that it is included in the flow hydrograph? (and if so, how does the bulking factor work in this case?) I have been running the model all this time with "do not bulk" option, does this mean I am modeling clear water?

    • @stanfordgibson
      @stanfordgibson 4 месяца назад

      The bulking option assumes your boundary condition is a clear water hydrograph and RAS is adding your solids to it. "Do not bulk" assumes that your boundary hydrograph is a time series of the whole mixture volume.

    • @stanfordgibson
      @stanfordgibson 4 месяца назад

      But, if you use the O'Brian or exponential rheology equations, those use Cv, so you can choose "do not bulk" and still have effects from Cv. If you choose user specified parameters and "do not bulk" the model will be insensitive to your Cv...assuming that you already included it in your boundary hydrograph. HMS includes both options, a bulk mixture hydrograph, or a clear water hydrograph and a Cv time series.

    • @TheBalticSun
      @TheBalticSun 21 день назад

      @@stanfordgibson thank you so much for answering! a last question is about the downstream boundary condition (DSBC), is it not mandatory to set de normal depth as the DSBC? can I only run the model with the upstream boundary condition? or does it depend on whether the flow passes through the mesh downstream?

    • @stanfordgibson
      @stanfordgibson 21 день назад

      @@TheBalticSun Because NN can "run out" (e.g. come to rest) before it reaches the "downstream boundary" you don't really need a downstream boundary if the flow doesn't reach the domain boundary. But if the flow does reach the domain boundary, you will need a normal depth or something.

    • @TheBalticSun
      @TheBalticSun 21 день назад

      @@stanfordgibson I got it, thanks again!

  • @GetnetMelaku-dn5rm
    @GetnetMelaku-dn5rm 4 месяца назад

    Thanks sir. thats helpful for ma paper. How to solve the error, Minimum error exceds allowable tolerance at ??? I am from Afrika Ethiopian 🇪🇹

  • @edwinkiprotich856
    @edwinkiprotich856 4 месяца назад

    Congratulations🎉

  • @Mr.G.77
    @Mr.G.77 4 месяца назад

    How to export the clone terrain to a raster for use in arcgis or other programs. Tried to use the export raster option, but it just export the image raster.

  • @Nash_W87
    @Nash_W87 4 месяца назад

    🎉🎉🎉

  • @vojtechkouba9367
    @vojtechkouba9367 4 месяца назад

    I'am very grateful for people like you.

  • @pierre-louisligier1845
    @pierre-louisligier1845 4 месяца назад

    Interesting! A quick question: how does RAS account for the fluid density of the debris flow mixture, and how to specify the material’s specific grain density? Density is often twice as large as clear water and can have significant impact on flow dynamics. Thanks in advance!

    • @stanfordgibson
      @stanfordgibson 4 месяца назад

      We compute fluid density based on the concentration by volume (CV) in the non-Newtonian fixed bed model, which means that for now we assume the solid phase has a specific gravity of 2.65. I suppose you could estimate higher density material with some sort of "apparent Cv" that converts mass in to volume...but I'd need to think/read more about that. Overall, though, most of the density effects are in the empirical parameters, not the physics, anyway, so I don't think it matters too much. In the mobile-bed sediment transport model you can edit the specific gravity of each grain class and simulate multiple grain density transport....but that is a much bigger effort.

    • @stanfordgibson
      @stanfordgibson 4 месяца назад

      I am going to post a video on Binham parameters in a couple months...if you would like to preview a rough draft, reach out ot me on linkedin and I can give you a link

  • @TheofficialPr0
    @TheofficialPr0 4 месяца назад

    Hello, i have written to you before. I'm working on my bachelors thesis on HEC-RAS sediment moddeling and have run into an issue while hydraulicaly calibraing my model. I have 6 gates in a SA/2D connections opening based on the rules i've set but based on my previous runs it seems like they dont follow the rules at all in fact most of the gates dont open at all. This has left me and all my professors confused since we do not see any problem with my model. Would you please help me because i have been trying to resolve this issue for over a month now and I'm at my wits end. Thank you very much.

    • @stanfordgibson
      @stanfordgibson 4 месяца назад

      I don't think I've tested connections with rules in a 2D sediment model. There is a chance that that particular confluence of features has a bug. If you believe there is a bug, please send the files to the RAS inbox www.hec.usace.army.mil/contact/

    • @TheofficialPr0
      @TheofficialPr0 4 месяца назад

      @@stanfordgibson I have not tried adding any sediment data yet because I can't calibrate the model hydraulicaly. I semt an email to the email you have send. I've run more tests and the gates just do not work...