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DELWAQ

DELWAQ is the engine of the D-Water Quality and D-Ecology programmes of the Delft3D suite. It is based on a rich library from which relevant substances and processes can be selected to quickly put water and sediment quality models together.

The processes library covers many aspects of water quality and ecology, from basic tracers, dissolved oxygen, nutrients, organic matter, inorganic suspended matter, heavy metals, bacteria and organic micro-pollutants, to complex algae and macrophyte dynamics. High performance solvers enable the simulation of long periods, often required to capture the full cycles of the processes being modelled.

The finite volume approach underlying DELWAQ allows it to be coupled to both the structured grid hydrodynamics of the current Delft3D-FLOW engine and the upcoming D-Flow Flexible Mesh engine (1D-2D-3D) of the Delft3D Flexible Mesh Suite (or even other models such as TELEMAC).

'DELWAQ in open source' is our invitation to all leading experts to collaborate in further development and research in the field of water quality, ecology and morphology using Delft3D. Feel free to post your DELWAQ related questions or comments in this dedicated forum space. If you are new to DELWAQ, the tutorial (in the user manual) is a good place to start. A list of DELWAQ related publications is available here.

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Sub groups
D-Flow Flexible Mesh
DELWAQ

Cohesive sediments & muddy systems

 


Message Boards

Using DELWAQ with a single-column hydrodynamics time series (U/V/density)

SB
Sebastien Blaise, modified 2 Years ago.

Using DELWAQ with a single-column hydrodynamics time series (U/V/density)

Youngling Posts: 2 Join Date: 1/27/17 Recent Posts

Hi,

 

I have been provided a time series of horizontal velocity and density at a single location along the water column, to be used in a pollutant dispersion study. It is a relatively flat area with little spatial variability of the hydrodynamics. 

 

Can such data be used in a Delwaq simulation? Should I generate a .hyd file from it?

 

Thanks

AM
Arjen Markus, modified 2 Years ago.

RE: Using DELWAQ with a single-column hydrodynamics time series (U/V/densit

Jedi Knight Posts: 223 Join Date: 1/26/11 Recent Posts

When I first read your message, I thought it was the wrong kind of question, but reading it more carefully, I realise what it is all about. Yes, as a matter of fact, you can use such data to construct a hydrodynamic database of sorts. Depending on what kind of resolution in the horizontal you want it could actually be easy. If you want one column, then the thing to do is: set up a one-column model with Delft3D-FLOW or D-FLOW-FM - use the number of layers you want and the layer thicknesses you want (the latter is not strictly necessary though). Then run it for a short period. This gives you the hyd-file and the grid files you need, as well as several others. You will then need to replace the volumes and the flows files: the volumes file contains the volumes per segment, per time. The flows file contains the flow rate through every exchange area  - flow velocity time surface area for both the horizontal and vertical exchanges.

The actual contents of these file is described in the manuals, but for a simple flow field as you indicate it is not hard to construct a proper set of such files.

SB
Sebastien Blaise, modified 2 Years ago.

RE: Using DELWAQ with a single-column hydrodynamics time series (U/V/densit

Youngling Posts: 2 Join Date: 1/27/17 Recent Posts

Thanks. It seems like a very pragmatic and efficient solution.

 

A follow-up question (I am a new user, still waiting for the GUI): can we model in DELWAQ a buoyant tracer that will sink/rise according to its density and concentration, despite the fact there is no feedback from the tracer distribution to the hydrodynamics? In other works: can DELWAQ include buoyancy effects due to a different effluent density compared to the ambient waters? 

AM
Arjen Markus, modified 2 Years ago.

RE: Using DELWAQ with a single-column hydrodynamics time series (U/V/densit

Jedi Knight Posts: 223 Join Date: 1/26/11 Recent Posts

Well, inorganic matter (IM1, IM2, IM3) are the substances we use to model suspended solids, but there is no reason why the settling velocity should be positive only. In fact I have used a _negative_ settling velocity to model microplastics lighter than water. Consult the manual to see if the current implementation wrt the settling velocity as function of salinity and the concentration suits your requirements. Otherwise it is possible to define your own processes vai "Open PLCT".