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

Possible bug with PCLT

Zhenlin Zhang, modified 3 Years ago.

Possible bug with PCLT

Youngling Posts: 1 Join Date: 12/23/16 Recent Posts
I am using Delft3d HMWQ 4.02.03, which I think is the latest version.
When I used PCLT to construct a simple substances file and saved it, I found that sometimes I had trouble opening the substances.0 file again in PLCT. It gave an error 'PCLT stops working'.
And then I found the problem was with certain process abbreviations not recognized by PCLT and these abbreviations are: DEBGRZ_G3, DEBGRZ_G4, and DEBGRZ_G5.
For instance, I chose just one substance: oxygen, but without activating any processes, and then I save the substances file.
When I tried to open that file in PCLT, it failed with the error 'PCLT stops working'.
But when I removed the lines about the processes DEBGRZ_G3, DEBGRZ_G4, and DEBGRZ_G5 from the *.0 file, I could open the file correctly.

So to work around this issue, I could manually remove these problematic processes each time I wish to modify the substances file, but it would be great if this problem could be fixed. Or please also let me know if there is anything I have not done correctly that is possibly causing the error as well.

Thanks a lot for your help!
Michel Jeuken, modified 3 Years ago.

RE: Possible bug with PCLT (Answer)

Jedi Knight Posts: 154 Join Date: 1/21/13 Recent Posts
Thank you for your post. Wealso experienced this problem, and only last week found out why this was a problem. It has been fixed by an upgrade of the process library with revision 7072 of the open source code of Delft3D:

Issue DELFT3D-35104 PLCT crashes when PO4 is added to the list of substances, even when there are no processes. The .0 file from the PLCT uses the keyword 'active', but also reads the description of the processes word by word. The new grazing process contains the word active in it's description which lead to a crash. Because the reading is case sensitive, capitalisation of active is a quick workaround. The PLCT will be fixed later.

When you use our open source version, please update your code, and rebuild.