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RE: Water Level Spikes in delft3dFM results

Abdulla Mohamed, modified 8 Years ago.

Water Level Spikes in delft3dFM results

Youngling Posts: 6 Join Date: 5/24/16 Recent Posts
hello.
I have been recently trying to calibrate a delft3d FM flow model with delta shell, and doing so did a comparison between the model predicted water levels and actual measured water levels.
It seem like model does predict the water levels relatively accurately but I keep seeing these water level spikes all through the time interval I modeled.
I have attached a picture showing this. The blue line is the FM Model, and the red line is the observations from NOAA. As seen from the figure the phase and the general agreement is good between the two, but with lots spikes for the modeled water levels.
I am wondering if anyone else encountered this while doing a flow run in delta shell.
If anyone could give me some pointers on what I could check to debug this, it will be very much appreciated.

Thanks in advance for all the help.
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Erik de Goede, modified 8 Years ago.

RE: Water Level Spikes in delft3dFM results

Youngling Posts: 16 Join Date: 1/7/11 Recent Posts
Dear Abdulla Mohamed,

The spikes in water levels are very strange. The spikes are in the order of 1 m and are sometimes even 3 m! Hereby my remarks on this:
*) Do spikes also occur at other monitoring stations?
If not, what is special to this location? A discharge nearby? Close to an open boundary? Is there a structure nearby? Etc.
*) Did you check the water levels at the times these spikes happen via map plots? For example, in case of the spike of 3 m how do the water levels look in the surrounding?
*) It is striking that the spikes seem to happen at the same phase: they occur about one hour after high water. Is this a coincidence? (I don't think so.)

With kind regards,

Erik de Goede
Deltares