intro story 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.




Sub groups
D-Flow Flexible Mesh

Cohesive sediments & muddy systems


Message Boards

Passing FLOW output to WAQ for coliform model

Moritz Lehmann, modified 3 Years ago.

Passing FLOW output to WAQ for coliform model

Youngling Posts: 8 Join Date: 1/16/15 Recent Posts
I am working on a shallow lake model with one vertical layer. I am confused why the coliform model coli04 appears to require separate time series for solar irradiance, water temperature and day length.

How can the model be configured to take these quantities from the FLOW model?

Also, how can I specify a time series of suspended particles (IM1), rather than modelling IM1 dynamically?

Thank you for your help!
Rudy Schueder, modified 3 Years ago.

RE: Passing FLOW output to WAQ for coliform model

Hi Moritz,

Of the 3 parameters you wish to send to DELWAQ, only temperature can be provided by FLOW. This is done by specifying something akin to the following in Block 7:

BINARY_FILE 'hydrodyn.tem'

Where the .tem file is a binary file produced by FLOW/WAQ coupling

Solar radiation can be supplied as follows:

INCLUDE '../coefficients and forcing/SWRad.txt';

where the format of the text file is:

2014/04/01-09:00:00 47.70081981
2014/04/01-10:00:00 53.58165705
2014/04/01-11:00:00 56.47385066

DayLength is a process in DELWAQ, so you can activate it to compute the day length.

To specify a time series of IM1, you simply need to:
1) remove it from the list of substances, so that it is no longer a state variable
2) create a FUNCTION as specified for RadSurf' above. This will make the parameter IM1 a time dependent and spatially uniform function.

I hope this helps,

Arjen Markus, modified 3 Years ago.

RE: Passing FLOW output to WAQ for coliform model

Jedi Knight Posts: 223 Join Date: 1/26/11 Recent Posts
As a further explanation of the requirement that solar irradiation, daylength, water temperature, etc. are to be specified as separate time series: within DELWAQ each process parameter can be specified as a constant, a time series that is uniform over the model, a value that is spatially varying but constant in time and a value that is both spatially and temporally varying. It is even possible to specify water quality parameters like salinity or the concentration of suspended solids via the input (in any of the above ways) instead of being calculated.

If you use the (old) Delft3D 4 user-interface you can control the type of data for the process parameter via the Edit window and its menu, if you use the (new) DeltaShell interface, you can specify its character in the tab window showing the values of the process parameters. In the more recent version you can specify the "segment function" type directly, no need to edit the input file as Rudy indicated.