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

Relation between grid cell size in Nesting

Angela T P, modified 4 Years ago.

Relation between grid cell size in Nesting

Hello everybody,

I am working with 2 nested grids and I am wondering if is there any restriction about grid cell size between both grids?. I mean, cell grid size (in finer one) should be between 1/3- 1/5 of cell grid size in coarser one?
I use this relation when I work with ddboundaries, but I dont know if I have similar restrictions with Nesting.

Thank you!
Angela T P, modified 4 Years ago.

RE: Relation between grid cell size in Nesting (Answer)

I obtained this response from Deltares. In the hope that it could be helpful for someone:

It is not necessary to use the same ratio each time when nesting, but a 500 m to 30 m nesting ratio may a bit too much. You could include for example a 100 meter intermediate grid. But then again, if the results from the 500-30 simulation are the same as the results from the 500-166-55-30 simulation, then there may not be a problem. It depends a bit on how large the 30 meter grid is. On the offshore boundary, the 500 to 30 nesting may go just fine, but on your lateral boundaries near the coast, some issues may arise.

Thank you very much!