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

Dwaq error

carlos` g zapata, modified 2 Years ago.

Dwaq error

Youngling Posts: 1 Join Date: 12/23/18 Recent Posts

I am working with Dissolved Oxygen model in a big estuary. After running Delwaq2 afther the first step I got ERROR in GMRES           1
 Stopped with error code :           1. I' ve changed the time step from 30 seg to 20 , 10 ,1. The problem still go on. I have attached the in, lst and lst file.


Could you help me to fix this problem.

Arjen Markus, modified 2 Years ago.

RE: Dwaq error

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

This is not the best time of year to expect answers fast, given the holiday season. One thing you can try is to set the constants Tolerance or MaxIter to different values:

CONSTANTS Tolerance DATA 1.0e-6


You can set them independently of each other. The first is the tolerance for stopping the iteration process - a larger value means the iteration will finish sooner with a possibly larger residual error, but there ought to be no significant effect on the concentrations. The second is the number of iterations that can be taken before the iteration process is terminated (and the whole calculation is terminated as well, because of lack of convergence).