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

Instability with Neumann Boundary

AL
Angang Li, modified 7 Years ago.

Instability with Neumann Boundary

Youngling Posts: 5 Join Date: 5/23/12 Recent Posts
Dear Deltares Community,

In my coastal simulation within Bocas del Toro, Panama, the run with Neumann boundary condition crashes almost immediately after "start", with error message as follows:

ERROR Water level change too high > 25.00 m (per 0.5 DT) after 2 timesteps in the following points:

However, when I switch to Water Level boundary condition keeping other parameters the same, it runs smoothly. The data of both boundary conditions were obtained from Delft Dashboard. Could someone suggest what might be the reason?

I have also attached my simulation files (with Neumann boundary condition) here, and I would be more than grateful if any comments / suggestions are given.

Best regards,
Angang
Qinghua Ye, modified 7 Years ago.

RE: Instability with Neumann Boundary (Answer)

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

I am not sure if the Neumann boundary condition provided in the zip file is correct or not. You might have to check how the Delft Dashboard generate the boundary. Furthermore, I suggest you can start with simple cases, like Neumann time series instead of astronomic.

Good luck,

Qinghua YE