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

incoming flow : zero concentration gradient of incoming flow.

hani ramadhan, modified 2 Years ago.

incoming flow : zero concentration gradient of incoming flow.

Youngling Posts: 6 Join Date: 3/31/13 Recent Posts

Dear all,

Is that possible to define zero gradient of concentration at open boundary so that the concentration of active substances will have the same number with ambient concentration? I need this because I don't have data about incoming flow concentration for some active substances. I really need advice about this.

Thanks and best regards

Hani Ramadhan

Arjen Markus, modified 2 Years ago.

RE: incoming flow : zero concentration gradient of incoming flow.

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

Unfortunately, no, that is not possible (a limitation of the implementation, not of the mathematics, although I can see some peculiarities in that respect ...). There are two ways I can see you can solve this:

* Do a calculation with the boundary concentrations set to zero and see what "overall" concentrations develop for these substances (that will work only if you have processes that form them or waste loads that introduced them, of course. Otherwise the concentrations will remain zero).

* Use the characteristics of these substances and measurements from similar water bodies to estimate the concentrations on the boundaries.


Note: even if a zero-gradient boundary condition would have been possible, it would only have worked if the conditions for the first solution are fulfilled.