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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RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

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Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
delft3d-wave boundary conditions
Answer (Unmark)
6/12/13 5:10 PM
I'm running a standalone WAVE model on a rectangular grid with domain boundaries as essentially: 1) the shoreline; 2) the offshore boundary (roughly shore parallel); 3) side boundaries are roughly perpendicular to the shoreline. I wish to specify time-varying (half-hourly) boundary conditions on the offshore boundary and at this stage am happy to apply a uniform condition.

Two approaches are apparent from the Delft3D-WAVE manual: the use of a wavecon.rid file (A.2.8.1) and the use of a .BCW file (A2.8.2).

Question: What is the distinction between the two approaches? The .BCW file appears to be the more versatile approach.

The manual indicates certain consequences of using the wavecon approach (e.g. the period value is assumed to be a peak period by default) and previous posts have suggested that the BCs in the wavecon file are applied to ALL domain boundaries. I have also observed the following runtime warning "Warning: ... degrees modified to power" which I presume refers to the directional spread parameter which is specified as provided in degrees in the *.mdw file and in the wavecon file.

Question: If the power representation of the directional spread is used, is the degree data provided in the wavecon converted to the equivalent power data?

Any thoughts on the above?

Ruairi
RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
Answer (Unmark)
6/21/13 2:40 PMas a reply to Ruairi MacIver.
Hi Ruairi,

Question: What is the distinction between the two approaches? The .BCW file appears to be the more versatile approach.

My answer: Yes. BCW file approach is a newer approach in Delft3D-WAVE.

Question: If the power representation of the directional spread is used, is the degree data provided in the wavecon converted to the equivalent power data?

My answer: Yes. It is converted to the power data.


Regards,

Qinghua
RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
bcw wave input file
Answer (Unmark)
1/2/14 7:42 PMas a reply to Qinghua Ye.
Hello Dear.Qinghua Ye

Special thank you ,Therefore According to your description the only way to simulate time varying wave parameters with space varying boundary conditions is Using BCW file. I would be appreciated if you tel me , which versions of Delft3D can support BCW file.

Best Regards

Mohammad
RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
Answer (Unmark)
1/3/14 10:42 AMas a reply to mohammad rahmanian.
dear Mohammad,

The feature of BCW is included in 2012. I am sure in all the versions from 2013, you can use the BCW files.

Otherwise let me know.

Regards,

Qinghua
RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
Answer (Unmark)
11/27/14 7:50 AMas a reply to Qinghua Ye.
Hi Qinghua,

Can you explain me more about "choice for degrees modified into power"?
If I understand well your answer, then the directional spreading input (in degree) on wavecon file will be converted to cosine power. But why is this happen? I did changed the directional spreading on spectral space to degrees (standard deviation).
However, the result shows different directional spreading between the one I put on the wavecon file with the directional spreading on the wavm file.
I attach csv file from wavm to make my question clear, including my input data. I hope you can help me to put this right. Thanks.

Regards,
Fajar
Attachments: directional spreading.csv (15.1k)
RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
boundary condition wavecon d3d-wave
Answer (Unmark)
12/4/14 11:32 AMas a reply to Fajar Khaedir.
Hi Fajar,

Certainly in the supported release 3.04.01.757of Delft3D, and in the open source tagged release 3426, the directional spreading values in a wavecon file are simply interpreted as an ‘s’ value regardless of what is selected in the GUI [or specified in the boundary section of the MDW file]. There was no conversion from one representation to the other.

This may have been modified in later releases, however I haven't used the wavecon approach recently so can't comment.

Regards
Ruairi
RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
bcw wave input file
Answer (Unmark)
7/15/17 3:26 PMas a reply to Qinghua Ye.
Hello Dear.Qinghua Ye
In wavecon we use "Mean wave direction", in TPAR file we use "Peak direction". The manual is not clear what direction we should use in .bcw file: peak or mean wave direction. I have the same doubt about the directional spread.
Thanks,
Kyssyanne
RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW
Answer (Unmark)
7/17/17 12:44 PMas a reply to Kyssyanne Oliveira.
Hi Kyssyanne,

If I remember correctly, the direction in BCW is the same as the definition of wavecon, i.e. mean wave direction. But I need more time to confirm it. After confirm it, I would update the Wave Manual as well.

Direction spreading is not relavant with this.

Greetings,

Qinghua