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-WAQ in parallel version

Ashok Khadka, modified 7 Years ago.

Delft-WAQ in parallel version

Youngling Posts: 3 Join Date: 6/19/13 Recent Posts
Can we compile and run the Delft-WAQ in parallel version ??
Michel Jeuken, modified 7 Years ago.

RE: Delft-WAQ in parallel version

Jedi Knight Posts: 154 Join Date: 1/21/13 Recent Posts
Yes, you can compile and run the Delft-WAQ in parallel version:

The multiprocessing is quite a new development which is generally
switched 'off', and can't be turned on using the GUI. You will
have to make an edit to the inp file used by the delwaq engine.
Please be aware that the GUI doesn't read the inp file, and
overwrites changes if you save from the GUI again.

A description of the inp-file can be found in
( There you will find
that you have to add an extra line to block 7 of the input
(before #7, but after #6), to specify the maximum number of
processors to be used. From the manual:

/Parallel computing

D-Water Quality supports parallel computing on multi core PCs.
This feature is generally switched ’off’. If you are confident
with your model, you may switch it ’on’ by giving:

CONSTANTS nothreads DATA 0.0 ; OMP-parallelism ’on’

With a value of 0.0 D-Water Quality will itself determine how
many threads can be used. With a positive value you determine the
number of threads. The default is -1.0 which means ’off’.
Implicit solvers need a Krilov space for each thread. This can
become large
for e.g. 6 core PCs with hyper-threading featuring 12 threads.
Then you better use a smaller positive number for the number of
threads than the allowed number of 12 that you will get with a
value of zero.

So use it, but with care,

Ashok Khadka, modified 7 Years ago.

RE: Delft-WAQ in parallel version

Youngling Posts: 3 Join Date: 6/19/13 Recent Posts
Thank you Michel !!