Hello, Why is it necessary to make a breakline and re-enforce cells where we are going to place an internal boundary condition (hydrograph) ? I am assuming that is to send water perpendicularly to the BC Line (in other words, to send water parallel to the slope), but i am not sure ?

Ben and Chris: what a clear and useful material, to revise our criteria. Thanks a lot.

Is there a digital elevation model accuracy that must be adhered to, especially in the vertical elevation, to define the floodplain exactly? Thanks

I have definitely run into many environmental restoration/habitat suitability problems where down river losses or gains to groundwater played a significant role in available flows and habitat suitability. Unfortunately, RAS doesn't allow for groundwater loss modeling in this way (it only subtracts groundwater loss from rainfall rather than calculating losses from the river bed to groundwater as flows move downstream). This certainly limits the use of RAS for environmental restoration problems, at least in California.

I have to say, your a treat for people working with HEC-RAS.

I would like to suggest SUDs for any of your next session please.

thanks for the huge amount of key tips. I wonder why travel time is not accounted for inside the storm sewer culverts, if Hec Ras is supposed to model the flow profile inside them? a time lagged operational rule for the gate at the entrance would help?

in min 51, when Chris suggests criteria for spacing the neighbor cross sections from the bridge, I think that one needs to see where is a significant change in channel geometry, for the case abutment is near vertical. As bridge curves are developed from momentum balance, pressure gradient term depends on depth gradient, which increases for large conveyance changes between cross sections.

Good demonstration

Good demonstration

about the phylosophical question on why energy gradient increases downstream I think it's because energy as elevation is by unit weight, but more weigth is converging in the narrow. It would be worthy to have longitudinal profile of integrated energy across the flow, to check calibration of structures e.g. bridge crossings, like Chris Goodel did in some video for 1D.

thanks a lot Krey. I have 2 ideas please for further contents, if you like: (1) since I ended my PhD I have wondered if is has been modeled in HecRas how climate change alters, along some years/decades, flood frequency via conveyance change due to channel morphodynamics. (2) intake sedimentation and ways to consider trash in the racks.

You're awesome. Thank you very much!!! +.+

After exporting the basin as a shp and opening it in qgis is not placing in a right place..any solution for this ?

Your videos are awesome. Thanks for making these!!

She was heavy on having to deal with sedimentation.. it would have been interesting to hear if she’s using any of Stanford’s sedimentation routines on these projects..

Damn This Guy is legit!! Thumbs up to you Good Sir👍

❤❤❤

Many thanks🙏

will this work in flat terrains?

One HEC-RAS video a day keeps unemployement away !

Cool!!

Is it recommended to align the mesh with the flow of the river (the cell faces are perpendicular to the movement of the water) or with the axis of the bridge? If it is the second option, is it necessary to repeat the mesh to cover the entire bridge (extending over the 2 bounding XS)?

What a podcast! Thanks. I did a monte carlo analysis for a dam breach project by chatgpt and it took it a minute to run 10000 simulations.

1:17:30 This has been my experience with AI assisted models. A lot of the early adopters are typically junior engineers who still need to hone their hydraulic modeling fundamentals that need to keep in mind some of the "commandments" from the previous episode. Good discussion!

Cool presentation. Quick comment - most of the screenshares were in low-resolution/pixelated. Your walkthroughs were detailed enough for me to follow but just fyi

Sean lied, he stole Chris' book from me

Hi, thank you for doing this video! You mentioned that you've done encroachment analyses where the water surface will go up when you encroach on the channel because of where you are in terms of the critical flow regime. Would you mind explaining that?

Great tips! A note on large HDF files- when working with bigger data on disk as HDF/NetCDF, it's crucial to benchmark your chunking and compression settings to optimize for low computation time or lower file sizes. I've noticed, depending on the computation you're doing, a simple chunksize change can speed up computation 100x, or a little compression can cut file size in half. RAS actually exposes these options in the GUI under Output Options/HDF5 Write Parameters/Advanced HDF Options. However, if you're working in RAS and hitting limitations from data size, IMO you just have too many cells and could probably simplify the model

Ras mapper doesn't want open in my computer any solution please

Is it possible to integrate sea water levels into the model for flood simulation? As I would like to investigate its impact on flood simulation of coastal urban areas

Hello, I am facing a difficulty that I cannot overcome with RAS Mapper. When displaying the results of a 2D simulation, I am looking for a way to display in each of the cells of the mesh only the value corresponding to the calculation point of the cell (a constante value for all the cell). I want to see only the calculated value and not projected on the terrain or interpolated between cells. Is there anyone who knows how to do this? Thanks in advance

?can would an animal drink salty sea water?

If I could thumbs up this video twice I would, it's such a great video and a real in depth video on lateral structures. I clicked on this video to see if It could answer my one question and ended up sitting through the entire thing just to continue learning about any tips. Using the measuring tool to create the xy coordinates for the lateral structures was genius. Again great video guys!

My commandment is using the "description" boxes within HEC-RAS (project one for overall model description, plan file specific run scenarios, bridge/dam for reference drawings/parameters, etc.) Makes it much easier to review a model or revisit one a few years down the line. Similar some of Ben's (like the notes/comments in the Python code). Good discussion on the .hdf files! Never used it with RAS, so I learned something new. Thanks for the shout out! Not sure about "prolific", maybe more infamous lol!

thank you so much. I was wondering how to design a lake bathemetry terrain within Hec-Ras. You made it so simple and smart. Create a detention basin just like creating a river, very inspiring.

Thanks for sharing!

That's more force multiplication than F1 driver legs on F1 brakes. LOOOOL

What are the Full Momentum ten commandments of HEC-RAS modeling? I'll start the list... 1.) Thou shall check the Courant number. 2.) Thou shall place proper ineffective areas. 3.) Thou shall use multiple opening analysis. 4.) Thou shall have sufficient htab parameters. 5.) Thou shall calibrate Manning's values. 6.) Thou shall perform stochastic modeling of breach parameters.

Wooow that was very good my leader

Nicely done!

Great!

Love you videos Kray. You have magic fingers.

This was so fun to watch!!

I've been using RAS for 10 years now. Heard about full momentum over the years through web searches trying to figure out issues and how to do thing in RAS. I'm a river restoration and fish passage engineer. Still always learning.

Thank you

Can this culvert be used to design underground penstock pipe from intake to powerhouse??

Awesome as always

0.04 at the large river scale and scale up to 0.1 at tiny intermittent tributaries. It would be neat to compile n values for a variety of different stream types- we work in the redwoods which are way different than urban/agrarian environments.

It was like watching your favorite movie!!!! So informative video. Thank you very much!!!!!!!!!