intro story Coast / Estuary

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. 
 

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

 

 

Message Boards

Flooding, Drying, Threshold depth

NB
Nophi Biton, modified 5 Years ago.

Flooding, Drying, Threshold depth

Padawan Posts: 38 Join Date: 8/1/13 Recent Posts
Hello everyone,

I'm a bit confuse of what will be the basis of wet and dry grid cell at the start of the simulation (t=0)? Will it be the threshold depth?

Please help.

I have attached the MDF and screen shot.

Dryflp= #YES#
Dpsopt= #MAX#
Dpuopt= #MEAN#
Dryflc= 1.0000000e-01

the depth values I have pointed in the screen shot shows that its greater than threshold depth (0.1m) but its not wet? how does this happen?
Qinghua Ye, modified 5 Years ago.

RE: Flooding, Drying, Threshold depth

Jedi Council Member Posts: 612 Join Date: 3/2/11 Recent Posts
Dear Nophi,

I don't know how Muppet interprets the dry and wet. But if you put an observation point in the specific point, and run one step, you can see exactly the water depth, water level etc.

By the way, I noticed that in the bathymetry figure you showd, more grid has negetative bathymetry. You might know that the bathymetry in Delft3D is always positive down. For example, a point with 100 is deeper than a point with 10. Just a reminding.

Regards,

Qinghua
NB
Nophi Biton, modified 5 Years ago.

RE: Flooding, Drying, Threshold depth

Padawan Posts: 38 Join Date: 8/1/13 Recent Posts
Dear Mr. Qinghua Ye,

Thanks for the reply.

Thanks for the idea of checking the actual water level. I have used QuickPlot to see if its indeed wet or dry and base on the time series plot it is indeed dry even if the bathymetry (depth) is below MSL (dpeth = 0.330 m).

The negative values represents the topography (above mean sea level). I am trying to model the extent of inundation for the storm surge event. The polyline represents the shoreline of my study area thus the left side is land and in the right its sea.

I'm still finding what is causing the problem.

I have run several simulations:
(1) using flood scheme (instead of cyclic) - still the same at first time step
(2) use different threshold depth 0.05m, 0.01m (default is 0.1m) - still the same at first time step
(3) unchecked Tides in processes - still the same at first time step
(4) use Depth at Grid Cell Centres = DP & Depth Grid Cell Faces = MIN instead of Max and Mean.

Any advise on how to trouble shoot this problem will be very helpful.

Thanks again for the reply.

Regards,

Nophi
Qinghua Ye, modified 5 Years ago.

RE: Flooding, Drying, Threshold depth

Jedi Council Member Posts: 612 Join Date: 3/2/11 Recent Posts
Hi Nophi,

It should not happen for sure. I don't understand. Can you give me your depth file, grid file and landboundary file?

Regards,

Qinghua
NB
Nophi Biton, modified 5 Years ago.

RE: Flooding, Drying, Threshold depth

Padawan Posts: 38 Join Date: 8/1/13 Recent Posts
Hello Mr. Qinghua Ye,

Thanks for taking time to take a look into my problem. I am also been bothered for quite a while of this problem. I can only think two points that can cause this : (1) could it be a bug on the code (2) could it bug on Quickplot (possibly couldn't identify 'wet' cells when its depth is too small?) NOTE: this are just my inference about the matter

Here are the attribute files. Please note that this is a nested model.


Thanks very much for your time.

Regards,

Nophi Ian Biton
Qinghua Ye, modified 5 Years ago.

RE: Flooding, Drying, Threshold depth

Jedi Council Member Posts: 612 Join Date: 3/2/11 Recent Posts
Dear Nophi,

I would say both of them have no problem.

I used the input you provided and specified a simple set of boundaries got the following results, which looks quite ok to me. In the figure Waterdepth.png, the interval of color is 2cm. So if the initial water depth is less than 10cm, it would be in white.

I also attached the model for you to check.

Regards,

Qinghua
NB
Nophi Biton, modified 5 Years ago.

RE: Flooding, Drying, Threshold depth

Padawan Posts: 38 Join Date: 8/1/13 Recent Posts
Thanks Mr. Ye for the suggestion. I have resolved my problem.
Qinghua Ye, modified 5 Years ago.

RE: Flooding, Drying, Threshold depth

Jedi Council Member Posts: 612 Join Date: 3/2/11 Recent Posts
Dear Nophi,

Can you share with other colleagues who are reading the forum? How did you solve that? Is there sth wrong or sth specific needed to be set?

Thanks in advance!

Qinghua