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

 

 

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Water level time series at open sea boundary

JK
Jonathan King, modified 5 Years ago.

Water level time series at open sea boundary

Youngling Posts: 16 Join Date: 9/8/15 Recent Posts
Hi,

I am trying to input a time series containing water levels along an open sea boundary into my model. The model ran successfully when set up using a simplified sea boundary time series defined in the GUI so I am happy the rest of the model is working.

At each cell along the sea boundary I have a month long time series of water levels obtained from a MIKE Global model. Because of the length of the boundary the tidal oscillations are not uniform and depend on location. In the GUI I have defined the boundary from [M1,N1] = [1,185] to [M2,N2] = [1,364] which covers 178 cells.

My questions are:
1) What is the correct format of the time series file
2) What is the reference point from which the water elevation is taken? In the original data format this is given from MSL

I have attached a sample .bct file in what I think is the correct format but cannot find any advice elsewhere in the forum or user manuals. The headers on the .bct file are shown below with some comments:

table-name 'Boundary Section : 1'
contents 'Uniform '
location 'C2C_RibbleModel '
time-function 'non-equidistant'
reference-time 20120801
time-unit 'minutes'
interpolation 'linear'
parameter 'time ' unit '[min]' ! First column, time (the original data format is in days from the model start time, I haven't yet changed it to minutes)
parameter 'water elevation (z) end ?' unit '[m]' ! Second column, position in sea boundary; [M1,N1] = [1,185]
parameter 'water elevation (z) end ?' unit '[m]' ! Second column, position in sea boundary; [M1,N1] = [1,186]
...
...
...
parameter 'water elevation (z) end ?' unit '[m]' ! Last column, position in sea boundary; [M2,N2] = [1,364]
records-in-table 178

! The following columns correspond to each parameter above
! Col1 - time Col 2 - Water Level at [1,185] Col 2 - Water Level at [1,186] ... Col 2 - Water Level at [1,364]
0.000 WL @ [1,185] @ 0.000 ... ... ...
0.021 WL @ [1,185] @ 0.021 ... ... ...
0.042 WL @ [1,185] @ 0.042 ... ... ...
...
...
...
... ! To last record in time series


Many thanks
Jon
JK
Jonathan King, modified 5 Years ago.

RE: Water level time series at open sea boundary

Youngling Posts: 16 Join Date: 9/8/15 Recent Posts
Hi All,

I've worked out the correct format of the time series input file and associated boundary definition file. I imagine others may have a similar problem and as I couldn't find any existing threads in the forum I have attached the .bnd and .bct files for future reference.

Jon
Dmitry Kushnir, modified 5 Years ago.

RE: Water level time series at open sea boundary

Jedi Knight Posts: 107 Join Date: 11/9/12 Recent Posts
Hi Jonathan,

The correct format of the bct-file can be obtained via using the GUI. A simple (blank) time-series boundary conditions file with needed initial dates could be generated and then edited by the text-editor. You can also have a look at the examples folder, I believe it should contain .bct and .bnd example files.

Regards,

Dmitry
Dmitry Kushnir, modified 5 Years ago.

RE: Water level time series at open sea boundary

Jedi Knight Posts: 107 Join Date: 11/9/12 Recent Posts
Regarding your second question - Water level error

Regards,

Dmitry
U
Jack Teo, modified 5 Years ago.

RE: Water level time series at open sea boundary

Hi Jonathan,

I just started using Delft and can I ask you a very simple question about boundary in FLOW?

I am running a test simulation with my own generated .dep but the results do not show any effects from the boundary. However, when I tested with a uniform depth i see the effects from the boundary.

Do you face similar problem before when you setup your model? Do i have to define the boundary in RGFGRID or QUICKIN before I select them in FLOW?
I am sorry but I am a bit desperate and no one is replying my thread before.

Thanks a lot. emoticon




Jack
U
Jack Teo, modified 5 Years ago.

RE: Water level time series at open sea boundary

I found what was wrong with my input. I was using negative values in Delft instead of positive. I was using another model before and it was the other way around. My bad.
U
Jack Teo, modified 5 Years ago.

RE: Water level time series at open sea boundary

I found what was wrong with my input. I was using negative values in Delft instead of positive. I was using another model before and it was the other way around. My bad.
JK
Jonathan King, modified 5 Years ago.

RE: Water level time series at open sea boundary

Youngling Posts: 16 Join Date: 9/8/15 Recent Posts
Hi Jack,

Sorry for not replying, I haven't checked the forum in a while! Yes that's a problem I had as the other model I was using (EFDC) required bathymetry data in the -ve depth format. As you said all you need to do is reverse the bathymetry values