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intro story DELWAQ

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.

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D-Flow Flexible Mesh
DELWAQ

Cohesive sediments & muddy systems

 


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PROBLEM: water level results with double peaks. Results aren't smooth

EE
Esther Espinoza, modified 1 Year ago.

PROBLEM: water level results with double peaks. Results aren't smooth

Padawan Posts: 25 Join Date: 4/6/17 Recent Posts
Hi, I'm simulating water level for a month period in an estuary and the results in the three monitoring stations have double peaks on almost all the data set, it is not smooth compared to the observed data even though the statistical indicators are fine. I have just one open boundary at the mouth of the estuary, I have used manning values between 0.012 and 0.030 and the eddy viscosity between 10-100. Also, I've done simulations with a reflection parameter alpha of 0 and 100 but it haven't solved the problem.

I'm just simulating water level and I'm just considering what I've mentioned before, the open boundary input data is in a time series format from tide gauge measurements of an institute, I plot that data and it is not a perfect smooth sinusoidal curve but it does not show double peaks (just in two peaks I think but it was small).

I read in another post a recommendation to smooth the bathymetry, which I did once and the results were not better. I will attach the graphics and I hope you can help me with this.

Thanks!

Note: The graphics don't show the complete month just a few days so the peaks can be seen but the whole month shows double peaks.



grid bathymetry and obs points


double peaks


open boundary data plot

Erin King, modified 1 Year ago.

RE: PROBLEM: water level results with double peaks. Results aren't smooth

Youngling Posts: 12 Join Date: 10/5/16 Recent Posts
I had a similar issue which I had to use the reflection parameter alfa at the open boundaries to fix. Have you tried experimenting with different values of this parameter? (It is set in the boundary definition file). Setting it very high may result in a phase offset in your simulated water levels though.
EE
Esther Espinoza, modified 1 Year ago.

RE: PROBLEM: water level results with double peaks. Results aren't smooth

Padawan Posts: 25 Join Date: 4/6/17 Recent Posts
Thanks for your answer. I did try different values for the reflection parameter but there was no difference in the results, I don't know why, but the curves were exactly the same for different values. However, I solved the problem interpolating the hourly data input for the open boundary to a 10 min interval. The peaks were gone, the curve was smooth and the statistical parameters were a little bit better.
Erin King, modified 1 Year ago.

RE: PROBLEM: water level results with double peaks. Results aren't smooth

Youngling Posts: 12 Join Date: 10/5/16 Recent Posts
Thanks for sharing how you solved it.