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

suspended sediment and salinity from FLOW to WAQ?

ZW
Zhanxian Wang, modified 1 Year ago.

suspended sediment and salinity from FLOW to WAQ?

Padawan Posts: 35 Join Date: 4/11/12 Recent Posts
Hi, all,

I am a beginner on DELWAQ. I want to know that when doing the coupling between FLOW and WAQ, can the suspended sediment (cohesive) and salinity be imported directly from FLOW results to WAQ? From the user manual and some discussions here, it looks like temperature can be imported directly. Has anyone tried salinity and/or suspended sediments?

Thanks,
Jonathan
Ben Williams, modified 1 Year ago.

RE: suspended sediment and salinity from FLOW to WAQ?

Jedi Knight Posts: 114 Join Date: 3/23/11 Recent Posts
Hi Johnathon (or Zhanxian?),

I'm pretty certain WAQ imports salinity and temperature from FLOW, perhaps just as density field, as ambient water density is needed in order to simulate outfalls in WAQ. However I am not aware of any capability to import sediment quantities from MOR (via FLOW) to WAQ.

WAQ does have a sediment transport module, albeit much simpler than MOR in terms of physics and numbers of sediment fractions considered.

Are you interested in using suspended sediment concentration to estimate light extinction?

Best regards,

Ben
AM
Arjen Markus, modified 1 Year ago.

RE: suspended sediment and salinity from FLOW to WAQ? (Answer)

Jedi Knight Posts: 222 Join Date: 1/26/11 Recent Posts
Ben is quite right, although there is no particular reason why the sediment results should not be transported to WAQ. It has simply never been considered, although that is for good reasons emoticon. The point is that MOR is about morphological changes and WAQ considers sediment as a vehicle for the transport of pollutants and as one of the compoments that determine the light climate (via extinction). That is, WAQ mostly considers the fine fraction - anything smaller than "sand".
As for salinity: if the hydrodynamic calculation includes salinity, then this will be exported by the builtin coupling (or by the external coupling program) as a file with the extension ".sal". Likewise: the temperature is in a file with extension ".tem", the vertical diffusion coefficient in ".vdf" and the shear stress in a file ".tau". These quantities can be imported as so-called segment functions. (It would be possible to do this for the sediment concentrations as well, but as I stated above, the need has never arisen.)
ZW
Zhanxian Wang, modified 1 Year ago.

RE: suspended sediment and salinity from FLOW to WAQ?

Padawan Posts: 35 Join Date: 4/11/12 Recent Posts
Hi, Ben and Arjen:

Thanks for the quick response. The study I have includes cohesive sediment related channel morphological change and cohesive sediment related water quality. I definitely will run FLOW model with salinity and cohesive sediment; however, for the water quality model, I want to avoid to calculate cohesive sediment again if I can transfer it from the FLOW model. Will I get the same cohesive sediment concentration in the water column from DELWAQ as the FLOW model if I use the same model grid and sediment characteristics?

From the coupling WAQ output from FLOW model, there are several files that look like related to sediment as shown in the attached figure: *.sed01, *.resflx01, *.sedflx01. What are these files? If they are related to sediment, can they be used directly in DELWAQ as inputs similar to salinity and temperature?

Thanks,
Jonathan
GS
Gholamreza Shiravani, modified 6 Months ago.

RE: suspended sediment and salinity from FLOW to WAQ?

Padawan Posts: 57 Join Date: 6/25/16 Recent Posts

Hi Wang,

did you find finally the solution to Import Sediment concentration from D-FLOW to WAQ? After coupling I have the corresponding file for all Parameters except of Sediment? How did you couple the Sediment files to use in WAQ? I will be appreciate if you answer my question.

GS
Gholamreza Shiravani, modified 5 Months ago.

RE: suspended sediment and salinity from FLOW to WAQ?

Padawan Posts: 57 Join Date: 6/25/16 Recent Posts

Hi Markus, could you tell me then how will Delwaq realize a segment, which is already filled with sediment in Morph, should excluded from computations in Delwaq? I mean, Delwaq without Morph and sediment modules from FLOW can not practically  provide right results!

AM
Arjen Markus, modified 5 Months ago.

RE: suspended sediment and salinity from FLOW to WAQ?

Jedi Knight Posts: 222 Join Date: 1/26/11 Recent Posts

I think you misunderstand something here: MOR is about the transport of sand (and other non-cohesive sediment), whereas DELWAQ is about cohesive sediment, so silt, mud, clay particles, also fine particulate organic material. The transport phenomena involved are quite different.