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RE: D-Flow tracer time series inside grid

Sebastian Martijena, modified 14 Days ago.

D-Flow tracer time series inside grid

Youngling Posts: 7 Join Date: 11/18/15 Recent Posts
It is possible in D-FLOW to set up a tracer time series discharge within the domain?
I want to simulate and instantaneous release of a tracer (like a plume, a patch/cloud of pulluted water that cover a number cells). This is the case when a sensor located in an estuary registers an abrupt increase/decrease of water quality parameter. The idea is to forecast the transport of the plume as it moves downstream, with a 2D simulation.One way is using many "point source" and assinging a low salinity value (at this point is a fresh water estuary and dont want to affect density). However I also want to "realease" several peaks of different tracer at certain interval time in order to know how the transport time (from this point to another place) is changing with de meteorological condition.
Hope to be clear. Thanks.
Dmitry Kushnir, modified 12 Days ago.

RE: D-Flow tracer time series inside grid

Youngling Posts: 9 Join Date: 11/9/12 Recent Posts
Hi Sebastian, 

If I understand you correctly, you want to put instantaneous sources of tracer to the model area?  

This is best simulated via space-varying initial conditions or edited restart files.  

In the (older) Delft3D-FLOW model a few matlab functions were available for this, which made possible to create space-varying initial conditions and restart files, namely delft3d_io_ini and trirst.  

You can create your own initial conditions, which contain i.e. a tracer cloud at the specific part of the domain, using Delta Shell spatial editor (see appendices D and H of D-Flow FM User Manual). Then you just have to start your simulation from those initial conditions and investigate the behavior of the tracer.  

Hope that helps,  


Sebastian Martijena, modified 11 Days ago.

RE: D-Flow tracer time series inside grid

Youngling Posts: 7 Join Date: 11/18/15 Recent Posts
Hi Dmitry,
Thank you very much for your help.
You understood me very well. That's what I want! Apologies for my rough English.
I had already tried using a restart file (to get the hydrodynamic conditions at the "spill" instant) and at the same time space-varying initial conditions for tracer concentration. However, it seems that restart file "prevails" over space-varying initial conditions and I don't get tracer cloud at the specific part of the domain.
I will try editing tracer concentrations in restart file (using a netcdf4 Python module) prior launching the simulation.
By the way, do you know how many tracers are supported? I used both GUI: the version as well as the Beta Suite
Any other suggestion is welcome.
Thanks for your time and for the contribution to the forum.