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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

RE: Wave & wind input reduction - how to implement in input files?

Gabriel Lim, modified 27 Days ago.

Wave & wind input reduction - how to implement in input files?

Padawan Posts: 32 Join Date: 5/5/18 Recent Posts

I am modelling medium- to long-term morphological changes of a beach. I have implemented wave and wind reduction techniques to produce a set of representative wave and wind conditions by seasons. I am running a 2DH simulation with online coupling between FLOW and WAVE modules. See example of representative conditions below:

These are the representative sets of wave and wind conditions for Autumn 2011:
Bin           Rep. Hs (m)    Probabilty    Tp (s)     Dir (deg)    Rep.Wind Spd (m/s)     Wind Dir (deg)
0-0.5              0.37                0.021         15.55         280                    3.21                              170
0.5-1              0.77                0.164           9.94         275                    3.98                              195
1-1.5              1.27                0.219         10.60         279                    7.77                              206
1.5-2              1.75                0.230         11.21         280                    8.16                              208
2-2.5              2.22                0.186         12.82         283                    8.21                              255
2.5-3              2.81                0.098         11.60         282                  11.65                              244
3-3.5              3.19                0.076         11.40         286                  12.13                              245

I want to input the representative wave and wind values with their respective weighting (probability of occurrence per year) into input files, but I cannot see anywhere in the manuals that indicates how this is done. Lesser (2009) who helped develop the Delft3D suite specifies that he used such techniques to implement input reduction techniques and thereby considerably reduced computational costs. If anyone has any idea on how to do this, please advise! Any help would be very much appreciated.

Many thanks in advance for your help and time!

Dmitry Kushnir, modified 26 Days ago.

RE: Wave & wind input reduction - how to implement in input files?

Padawan Posts: 85 Join Date: 11/9/12 Recent Posts
Hi Gabriel,
Have you made a progress in time reduction for Delft3D morphology simulation? I'm not an expert on this, but I think you're probably looking for Morfac technique. See this Msc thesis for more details: https://www.utwente.nl/en/et/wem/education/msc-thesis/2015/wilmink.pdf
Please, post about you findings here, so other could  learn how to do this.
Gabriel Lim, modified 26 Days ago.

RE: Wave & wind input reduction - how to implement in input files?

Padawan Posts: 32 Join Date: 5/5/18 Recent Posts
Hello Dmitry,

Thank you for your reply and for sharing the MSc thesis. Yes, I am aware of the morfac technique, and I intend to use it in conjunction with the aforementioned input reduction techniques. As briefly mentioned in my previous post, Lesser (2009) used a representative set of wave and wind data, as well as a morphological tide (representative tide condition) on top of the morfac - further reducing the computational times. Examples of such combinations of input reduction and morfac can also be found in literature (e.g. Luijendijk et al., 2019).

If I found out how to implement these representative conditions into the input files for D3D, I will be sure to share them here also. If anyone has any idea or information, please let me know! Many thanks.

P.s. in case anyone is interested, the references for the publications I cited are as follows:
-Lesser, G. (2009). An approach to medium-term coastal morphological modelling. PhD thesis. UNESCO-IHE, Netherlands.
-Luijendijk, A.P.; de Schipper, M.A.; Ranasinghe, R. (2019). Morphodynamic Acceleration Techniques for Multi-Timescale Predictions of Complex Sandy Interventions. Journal of Marine Science and Engineering, 7, 78.
Adri Mourits, modified 14 Days ago.

RE: Wave & wind input reduction - how to implement in input files?

Yoda Posts: 1224 Join Date: 1/3/11 Recent Posts
Hi Gabriel,That's a so called "wavecon.<runid>" file. This functionality is outdated, not supported and not described in the manual. But it still works. Attached is a set of input files containing a wavecon file. You are free to use it, but support is not guaranteed.Regards,Adri
Gabriel Lim, modified 13 Days ago.

RE: Wave & wind input reduction - how to implement in input files?

Padawan Posts: 32 Join Date: 5/5/18 Recent Posts
Hi Adri

Thank you for your reply and help! I wonder, can this option be used in the online-coupling with FLOW-WAVE? Is there anywhere I can find more information regarding this process and how to carry it out? Ideally I want to include representative values for waves and wind for an online coupled simulation. Do I include the representative wind values in the wavecon file as well instead of the "physical parameters" tab of the FLOW GUI? Or do the values need to be put into the FLOW-GUI separately as well as the wavecon file? The WAVE user manual says in Appendix A.2.8.1, it says:

"To use this Wavecon option, just simply add the <wavecon.rid> file to the working directory and the system will use the file automatically. A WAVE computation is always performed on a certain time point (based on the reference date). If a <wavecon.rid> file exists in the working directory, it will get its wave boundary
conditions (including wind and water level) from that file. The boundary condition values in the default <rid.mdw> file will not be used then. When the time point of the wave computation lies between two prescribed time points in the <wavecon.rid> file, it will interpolate the wave, wind and water level conditions between these two time points."

So I assume any boundary, wind, water level values input into the WAVE-GUI in standalone runs would be replaced by the values in the wavecon file, but what happens in the FLOW-WAVE coupling? Please advise. Thank you!

Kind regards,