Coast / Estuary

Coastal systems are among the most dynamic physical systems on earth and are subject to a large variety of forces. The morphodynamic changes occurring to coastlines worldwide are of great interest and importance. These changes occur as a result of the erosion of sediments, its subsequent transport as bed load or suspended load, and eventual deposition. 
 
Estuaries are partly enclosed water bodies that have an open connection to the coast. Estuaries generally have one or more branching channels, intertidal mudflats and/or salt marshes. Intertidal areas are of high ecological importance and trap sediments (sands, silts, clays and organic matter).
Within the Delft3D modelling package a large variation of coastal and estuarine physical and chemical processes can be simulated. These include waves, tidal propagation, wind- or wave-induced water level setup, flow induced by salinity or temperature gradients, sand and mud transport, water quality and changing bathymetry (morphology). Delft3D can also be used operationally e.g. storm, surge and algal bloom forecasting. 
 
On this discussion page you can post questions, research discussions or just share your experience about modelling coastal and/or estuarine systems with Delft3D FM. 
 

** PLEASE TAG YOUR POST! **

 

 

Sub groups
D-Flow Flexible Mesh
DELWAQ
Cohesive sediments & muddy systems

 


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RE: Restart from Map

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Restart from Map
restart map
Answer (Unmark)
10/21/13 3:42 PM
Hi All,

I'm having some trouble restarting from map files in my current model. I'm not sure what's going on, I haven't had this problem in the past, but now when I restart from a map, the system reinterpolates the surface, and changes some of the topography. You can see this in the attached image. The bottom figure is the map that I am starting from, and the top figure is the start of the new run. Since the dates are the same, the topography should be identical, but you can see that the channels in the start o the new run are much wider than they had been.

Do you know what's going on here?

I'm also attaching my run files, in case that helps.

-Chris
Attachment

Attachments: ChannelInterp.png (265.8k), postA.zip (35.1k)
RE: Restart from Map
Answer (Unmark)
10/28/13 5:19 PMas a reply to Christopher Esposito.
Bump!

Anybody have any ideas on this? It's actually becoming a major problem for me, because it means that if a long term simulation crashes then I have to restart from the beginning with a smaller timestep andhope for the best.

The problem may not be entirely clear until you open the .png file. The preview shown in the post doesn't give an idea for the severity of the issue.


-Chris
RE: Restart from Map
Answer (Unmark)
11/1/13 11:36 AMas a reply to Christopher Esposito.
Hi Christopher,

First I thought it has to do with drying/flooding. But according to your description that is not the case here. It really has to do with the bed level being changed when restarting, right?

I'll have to discuss it with my colleagues.

Regards,

Adri
RE: Restart from Map
Answer (Unmark)
11/1/13 4:52 PMas a reply to Adri Mourits.
Thanks Adri,

It is actually changing the bed level on restarting from the map file. I thought at first that I was tracking too many underlayers, but I still had the problem when I reduced them. I've also gotten a suggestion that running the model with "Depth Specified at Grid Cell Centers" might alleviate the problem, but I haven't been able to try that yet.

If you have a speedy internet connection, you can see the problem in action by downloading one of my model runs from this dropbox link:

https://www.dropbox.com/s/c8miw14zcwzu2nw/postD_forAdri.zip

It's about 350MB, zipped. If you try to start postD02 from the last map of postD01, you might be able to see what's going on more clearly.

Thanks for your help.

-Chris
RE: Restart from Map
Answer (Unmark)
11/8/13 8:46 PMas a reply to Christopher Esposito.
Adri,

Running the models with Depth Specified at Cell Centers seems to be solving the problem. I'm surprised, becasue I've never noticed this issue before, and i think that most of my models have been run with Depth Specified at Cell Corners, but at least this seems to be a workaround for the moment.

-Chris
RE: Restart from Map
Answer (Unmark)
11/12/13 8:08 PMas a reply to Christopher Esposito.
Hi Chris,

The morphology module updates the bed levels in the cell centres. The trim-file also contains the time series of bed levels at cell centres. Upon restart from a trim-file, the dpsopt flag is automatically switched to DP. The tri-diag.postD02-001 file contains a line

*** WARNING DPSOPT value reset to DP because of restart

to indicate that. So, why doesn't it work?

It seems that this feature doesn't work with parallel computing. Although the flag is changed for the first partition, the other three tri-diag files don't include such line. These partitions assume that the bed level has been specified at the corner points and use MAX to "interpolate" the data to cell centre. You may observe that in 1/4 of the domain the restart is done correctly. By manually switching the dpsopt in the mdf file to DP, you make sure that all partitions use the correct flag.

Now we know what caused the problem, we'll fix it.

Cheers,

Bert
RE: Restart from Map
Answer (Unmark)
7/26/17 4:04 AMas a reply to Christopher Esposito.
I am a new user delft 3d. I have beeing try to set up a river model. I really need your help. Could you tell me how to restart model from map files?
Thank you very much!!
Best regards.
Chunping ren
RE: Restart from Map
Answer (Unmark)
8/2/17 6:12 PMas a reply to Chunping Ren.
Hi Chunping,

The GUI will help you to set up a model including restarting. See the Delft3D-FLOW User Manual, section 4.5.5 Initial conditions.

Regards,

Adri
RE: Restart from Map
Answer (Unmark)
8/9/17 11:35 AMas a reply to Adri Mourits.
Hi Adri,
I got it! Thank you very much!
Chunping