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

Nesting wave/roller model

JH
Jeff Hansen, modified 8 Years ago.

Nesting wave/roller model

Padawan Posts: 29 Join Date: 7/12/11 Recent Posts
Hi,

I was wondering if anyone has ever nested SWAN much like you would a flow model (with a lot of boundary segments). In my case am looking at a beach with a submarine canyon just offshore that leads to a strongly 2-D variable wave field. Ideally I would like to run my regional SWAN model for an entire month and then extract the BCs for a much smaller domain (of the same size as my surf zone flow model) which I can then run for shorter time periods along with a high resolution flow model. Problem is that SWAN will only let you have a limited number of boundary segments (50-60 I believe), given the variability in my waves I would like to have a boundary segment for ~every grid cell along the boundary of my small model. Is anyone aware of a way in which to do this? An even more ideal scenario would be to not have to run SWAN at all again and use the built in roller model with the direction/frequency saved from an earlier SWAN run.

Any ideas.

Regards,

Jeff Hansen
Renan Ribeiro, modified 8 Years ago.

RE: Nesting wave/roller model

Padawan Posts: 55 Join Date: 3/23/11 Recent Posts
Hi Jeff Hansen

You can try to force DELFT3D-WAVE with a space-varying spectral file produced by SWAN.
Take a look at this question

Regards,
Renan Ribeiro
JH
Jeff Hansen, modified 8 Years ago.

RE: Nesting wave/roller model

Padawan Posts: 29 Join Date: 7/12/11 Recent Posts
Renan,

Thanks, I think this will work.

I just have to figure out how to get swan to save and append the 2D spec file for each stationary swan simulation into a single bnd file, in my case this is just the nes003 file (I have three domains and want to run the first two independently) for each run. Looks like either POINTS or NESTout commands from SWAN manual. This will probably take some use of sed/tr to intercept the swan input file made by delft3d-wave.

Unfortunately I suspect the 2d spec file may get so large as to slow things down.

Thanks again

Jeff
Renan Ribeiro, modified 8 Years ago.

RE: Nesting wave/roller model

Padawan Posts: 55 Join Date: 3/23/11 Recent Posts
Hi Jeff,

I'm not very familiar with swan setup, but i think is something like this. In Swan on DELFT3D-WAVE you need to check the box "Output for specific location" at "Output parameters" tab and load a xy file with the points of the grid.

To append the 2D spec file for each stationary run, you can use a matlab script (swan_io_mergesp2.m) from OpenEarth.

Regards,
Renan