intro story Coast / Estuary

Coast / Estuary

Coastal systems are among the most dynamic physical systems on earth and are subject to a large variety of forces. The morphodynamic changes occurring to coastlines worldwide are of great interest and importance. These changes occur as a result of the erosion of sediments, its subsequent transport as bed load or suspended load, and eventual deposition. 
Estuaries are partly enclosed water bodies that have an open connection to the coast. Estuaries generally have one or more branching channels, intertidal mudflats and/or salt marshes. Intertidal areas are of high ecological importance and trap sediments (sands, silts, clays and organic matter).
Within the Delft3D modelling package a large variation of coastal and estuarine physical and chemical processes can be simulated. These include waves, tidal propagation, wind- or wave-induced water level setup, flow induced by salinity or temperature gradients, sand and mud transport, water quality and changing bathymetry (morphology). Delft3D can also be used operationally e.g. storm, surge and algal bloom forecasting. 
On this discussion page you can post questions, research discussions or just share your experience about modelling coastal and/or estuarine systems with Delft3D FM. 




Sub groups
D-Flow Flexible Mesh
Cohesive sediments & muddy systems



Message Boards

Delft Flow-WAQ coupling error

Narayanage Nirmal, modified 3 Years ago.

Delft Flow-WAQ coupling error

Youngling Posts: 1 Join Date: 4/5/17 Recent Posts
need help!!!
I am trying to couple flow and waq modules.

The flow model ran successfully and generated the com- file for the coupling. But, When I try to run the coupling program, I get the following error message. Can anyone suggest what might be wrong in my flow or coupling set up? Thanks

Delft3D-FLOW - Water Quality
Deltares, COUP203 Version, Jan 18 2013, 09:42:45

PC/Windows/Linux version

ERROR: integer expected, but not found ??
are you using the correct input file ??
for input files of => v2.4 use header:

Exit from Delft3D-Coupling

child process exited abnormally
Michelle Jeuken, modified 3 Years ago.

RE: Delft Flow-WAQ coupling error

Jedi Knight Posts: 154 Join Date: 1/21/13 Recent Posts

From your message I could only suggest what the message already says: are you using the correct input file ??

Besides that I could strongly advise you to use the online couling program in your flow runs. Switch on Export WAQ input, and use the edit WAQ input button to go to the next screen, and make the correct settings.

Michelle Loozen, modified 2 Years ago.

RE: Delft Flow-WAQ coupling error

Youngling Posts: 2 Join Date: 6/27/18 Recent Posts

Hi all,

Im having the same problem. 

I would like to couple the results from FLOW in the PART tracking module.

However the flow model does not create a 'COM' file and output of Delft3D flow I could not select the 'online coupling' bottom.

What could i do? 


Michelle Jeuken, modified 2 Years ago.

RE: Delft Flow-WAQ coupling error

Jedi Knight Posts: 154 Join Date: 1/21/13 Recent Posts

Hi Michelle,

If you couldn't see the 'Export WAQ input' option, or in older FLOW GUI versions, the 'online coupling' at the bottom of the output section, that could only be if you have a very old version of the FLOW GUI (>5 years). Email to for a newer version of the (oss) GUI.

If you also don't see a com-file, things you could check are the start and stop timers and the interval. When the interval is zero, the com-file will not be produced. The same goes for the preferred 'Export WAQ input' option, that will only produce a hyd-file (that is directly usable by PART) when the timings are correct.




HARRISON an, modified 7 Months ago.

RE: Delft Flow-WAQ coupling error

Youngling Posts: 1 Join Date: 7/17/20 Recent Posts
The Delft flow project is most competent and successful run flow model. But sometime you might face error in running this model. To solve this error you should make some changes in setting for proper working. The is one of the competent forum for reviewing your articles.