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. 
 

** PLEASE TAG YOUR POST! **

 

 

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

 

 

Message Boards

Using non uniform values of currents along the grid in the D3D-Wave module

MT
Manuel Taborga, modified 7 Years ago.

Using non uniform values of currents along the grid in the D3D-Wave module

Youngling Posts: 7 Join Date: 11/30/12 Recent Posts
Hi guys,

I have to incorporate currents to my D3D-Wave model, but the only way to introduce them into the Wave-GUI is with an uniform value of them all along the grid, defining it with an "u" and "v" uniform values for the velocities of the currents. But I have several different current values along an uniform grid generated with the SWAN and now I would like to add them to my Wave model but I can't do it with the GUI and I would like to know if there is a way of working with them in an offline way and modyfing my .mdw file. Is it possible?


Thanks in advance


Manuel
Qinghua Ye, modified 7 Years ago.

RE: Using non uniform values of currents along the grid in the D3D-Wave mod

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

Sorry I didn't reply your question at link: http://oss.deltares.nl/web/delft3d/coast-/-estuary/-/message_boards/view_message/240874/maximized.

There are 2 ways to solve this:
1. you can apply the trick mentioned by Adri, "Write a script." You can do the same trick here to update the swn or mdw files.
2. you can probably use the new function we developed for Time-varying and space-varying wave boundary conditions using BCW files. Refer to the section in wave manual (after Version: 3.05.25238):
A.2.8.2 Time-varying and space-varying wave boundary conditions using BCW files

In the mdw file, you can split the boundaries into segments and specify different velocities and wind, wave inputs.

Regards,

Qinghua
MT
Manuel Taborga, modified 7 Years ago.

RE: Using non uniform values of currents along the grid in the D3D-Wave mod

Youngling Posts: 7 Join Date: 11/30/12 Recent Posts
Hi Qinghua,

I have been reading carefully the new manual (v. 3.05.25238) of the WAVE module and, specially, the A. 2.8.2. section but, after all, the only way to incorporate my current values are only at the boundaries but not inside of them. I mean, I have a grid of current values (x and y velocities) and I want to incorporate all of them to the model not only at the boundaries but also in the rest of the computacional grid. I think it is possible with SWAN but I don't know if it is enabled in the WAVE module (in the offline mode). On the other hand, I have incorporated wind fields in my model on a equistant grid as appears in the wave manual(pages 176-180) and I believe it would be the easiest way to introduce my current values in the model if it was possible in the offline mode because you only have to define a new grid and just put the values inside a new file you have created. It would be great!

Thanks in advance!

Regards,

Manuel
Qinghua Ye, modified 7 Years ago.

RE: Using non uniform values of currents along the grid in the D3D-Wave mod

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

Indeed, the new feature of wave boundary only allows you to specify the time/space varying current.

If you want to set a new current info at every grid point, other than the current info from FLOW, you can either modify the com file or insert your new info to wave by scripts. You don't need a new grid, I suppose.

Hope this helps a bit,

Qinghua
MT
Manuel Taborga, modified 7 Years ago.

RE: Using non uniform values of currents along the grid in the D3D-Wave mod

Youngling Posts: 7 Join Date: 11/30/12 Recent Posts
Hi Qinghua,


Firstly, I would like to thank you your help and suggestions.

Secondly, I have to comment you that I am using the WAVE in the standalone mode (without using FLOW). I am using the WAVE only to calculate my Hs and Tm (mainly) in front of the port of Barcelona, because with this info I can feed other model (IH-MSP) based on the elliptic mild slope equations to study with more detail the interior of the port (mainly, resonance). Besides of waves and the wind (set offline on a equistant grid different to the computational mesh which it is made with RGFGRID) I would like to include a field of currents into the model. I have several current values on another equistant grid (different to the wind-grid and, also, the computational grid, sorry for the mistake in the previous message). These values are constant in the time because I am studying for a stationary scene (for only 1 hour). These currents are parallels to the coast line, mainly from NNE to SSW. Also, the mean sea level remains uniform for this period of time.

I. Using FLOW and WAVE modules:

According to your response I guess that, somehow, it is possible to take into account these currents only using the FLOW(I have never worked with it, only with the WAVE). I have an overview of the FLOW manual and I think that these values are only possible to set by the GUI or by ".bct" files, but only at the boundaries not inside of them(grid). So, we find the same problem as we had in the WAVE: only it is possible at the boundaries. a) Is it possible to include them (all my current-field, not only at the boundaries)? Besides, you suggest to modify the com-file, but b) I don't know how exactly because I have never seen the info which contains inside of them (it doesn't appears in the manual, even, in the appendices: A. Files of Delft3D-FLOW.) And c) if I could include them with the FLOW, what it would be the best way to work with the FLOW: running togheter by reading the flow file ".mdf" from the WAVE-GUI or by using only the FLOW-GUI (defining my Flow and Wave inputs) in this case (waves + wind + currents)?


II. Using only WAVE module:

And, finally, you suggest me to insert my new info (currents?) to wave by scripts, d) but how exactly? I don't understand how to do that, although it seems to be the easiest way to include my field of currents into my WAVE-model.

e) Is it worth using this method using only WAVE instead of coupling WAVE+FLOW? in terms of accuracy, adjustment to reality, ...


Thanks a lot!! Because sometimes I feel a bit lost, sorry...


Regards,


Manu