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

RE: delwaq ebullition from sediment

MI
Mayra Ishikawa, modified 26 Days ago.

delwaq ebullition from sediment

Youngling Posts: 1 Join Date: 3/26/15 Recent Posts
I am studying its hydrodynamics and water quality with Delft3D FLOW and WAQ, and colleague studies the emissions of GHG and has ebullition data from bubble traps that were deployed in the reservoir.
We would like to compare measurements and simulations, but we are struggling in figure out how to export the simulations ebullition results from the sediment for a comparison. The –bal.his file only gives the option to extract fluxes from the water column, which then only have null ebullition.
The report “Modelling of the Nam Theun 2 Reservoir: Water quality and greenhouse gases emissions” (2009) was being used as a guide for us, and we saw that CH4 concentrations from pore water of the sediment was exported from the model.
At the moment only the layer S1 in sediment is being used.
Hope that someone can give us an insight of how to obtain this data if possible.
Attached there is the .sub file.

Thanks in advance!
AM
Arjen Markus, modified 20 Days ago.

RE: delwaq ebullition from sediment

Jedi Knight Posts: 224 Join Date: 1/26/11 Recent Posts
The ebullition process is part of a collection of processes that mainly take place in the sediment. You need to use the so-called "layered-sediment" approach for it to work properly in the water and the sediment. (Note: we are working on an alternative, as the "layered-sediment" approach turned out to be incompatible with other developments.) If you want to avoid that, then perhaps the best short-term solution is to mimick the process yourself via the Open PLCT approach. 
LB
Lora Buckman, modified 12 Days ago.

RE: delwaq ebullition from sediment

Youngling Posts: 4 Join Date: 2/4/21 Recent Posts
It's strange to me that the process flux would not be incldued in the balance file, even using the S1 approach, if the process is activated. Unless the processes cannot be or is not used with the S1 approach. You could check in the lsp file whether the process is activated. I agree with Arjen that it would be better to use the layered sediment approach instead of the S1 approach when you are spcifically interested in processes within the sediment. The fact that pore water concentrations were used in the referenced report indicates that there the layered sediment approach was also used. There is an "old style" and "new style" (c.a. 2020) layered sediment approach which works with different versions of Delft3D-WAQ. Advice on how to implement this would depend on which version you intend to use.