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

Simulation error due to bathymetry

SC
Simon Colman, modified 1 Year ago.

Simulation error due to bathymetry

Youngling Posts: 5 Join Date: 10/2/18 Recent Posts

Dear, 

For my thesis I am modelling a simplified version of the Scheldt Estuary. I have been working with a laterally uniform depth (rectangular cross-section) that follows a curve in the longitudinal direction and have had no problems with the results. When I introduce a new bathymetry, changing laterally as well, the simulation seems to run but the time is halved (which is weird) and only "NaN" results are produced (for every output parameter). I have done many checks and conclude that the problem lies with the new bathymetry, but I do not know why or how to fix it. The hydrodynamic grid and bathymetry are read and can be outputted by QUICKPLOT but no other hydrodynamic or transport parameters. Please help, I have put my input files in attachment. A test FLOW-file is included to show that for the simplest simulations, no results are shown.

Richard Measures, modified 1 Year ago.

RE: Simulation error due to bathymetry

Jedi Knight Posts: 178 Join Date: 3/23/11 Recent Posts

Hi,

I had a very brief look at your *.dep file and I think you may have the sign convention wrong. Bed level in Delft3D is specified positive downwards i.e. -3m is above datum (generally dry land in a coastal model) and +3m is below datum (wet). InQUICKINit is easy to multiply the depth file by -1 to reverse the signs.

Cheers, Richard

SC
Simon Colman, modified 1 Year ago.

RE: Simulation error due to bathymetry

Youngling Posts: 5 Join Date: 10/2/18 Recent Posts

Hi Richard, 

 

thank you so much for your reply! I had noticed it as soon as I posted this thread, but it comforts me to know that you are still active and replying quickly on this forum. 

Anyways, thank you! I felt like such an idiot!

 

Kind regards

 

Simon