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NEGATIVE DEPTH WARNING

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Hi,

When a “NEGATIVE DEPTH WARNING: For entire mesh” appears, I have to move the Marsh porosity parameters? someone in particular?

I`m using the following parameters: AC1=1.8, AC2=1.2, AC3=0.02 and AC4=-0.9,

My highest topographic elevation is 1.2 m, and my tidal range 1.2 m.

Thank you.

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RMA2 requires that all nodes in a mesh start wet. This is unfortunate particularly in flooding situations.

In a steady state situation, generally you can use the steering module to get to the boundary condition you are interested in. In a dynamic situation, you can pad the start of your simulation with a curve that starts with an abnormally high downstream water surface elevation and gradually lowers until it meets where you want your simulation to begin. Then you morph the curve into your tidal boundary condition. Remember to include some extra tidal information to give the model time to settle into the tidal regime. The starting water surface elevation in the model parameters section should match the initial value of the boundary condition curve.

Unfortunately, RMA2 may prove somewhat finicky in this situation. If it is an option, you may want to consider using one of our more stable models such as TUFLOW or SRH (through the generic model interface). These models do not require meshes to start all dry and are much more stable when elements wet or dry.

Hi,

When a “NEGATIVE DEPTH WARNING: For entire mesh” appears, I have to move the Marsh porosity parameters? someone in particular?

I`m using the following parameters: AC1=1.8, AC2=1.2, AC3=0.02 and AC4=-0.9,

My highest topographic elevation is 1.2 m, and my tidal range 1.2 m.

Thank you.

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Hi Rusty

I encountered the same problem with him as well. I keep on getting this message NEGATIVE DEPTH WARNING : For entire mesh=552 For active nodes=552. STOP depth convergence exceeds 50.0.

My max Z value is 103.5 and my target head is 99.8. I have already gradually lower the head from 103.5 until 99.8m by 0.1m difference from each time step and yet I still getting the same error message and the model is not able to be run.

I tried the steering module as well, by putting the Inital condition (%of target) =104 (103.5/99.8) and Min Step (%of target) = 0.1 (0.1/99.8). When i clicked RUN RMA2, it didnt move at all and it stops. Saying error.

I believe you could help me on this and explaining what on earth happened in my model.

Thank you so much.

Regards

Vera Kurniawan

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Hi everybody!

I'm having the same problem....

Has anyone of you got a solution with RMA2??

 

I'm trying to use the Rma2 spindown tool in sms to solve the convergence problems for my stream model.

The stream has two boundary conditions:

-upstream: constant flow of 0.05cms

-downstream: a transient tidal level with a peak of 1.64m

The highest point of the mesh is 5.61m

As I have read in a previous post in the forum and your recomendación I should use rma2 spindown tool to aid rma2 to converge with hotstart boundary condition.

I have a question: as  I have a transient boundary condition in the water level I cant figure out if the spindown tool is suitable for my problem because the data needed for the steering process to begin is a % of the desired final water level in the boundary condition (in my case it's 5.61m/1.64m = 342.07%) but my BC is a tidal function....

Is that correct?

I also tried to run the model with a constant level (in stationary condition) and tried to run the spindown and I set my 342% in the spindown data entry and nothing happens. The program opens two charts and it stays in iteration 0 of 50 and never ends. A steering file is created and also a steering status file  where it says 

running Gfgen 1...

Run began at time 15:32:0-18

After 40 minutes nothing changes.

I think the tool doesnt work properly.

Can you help me??

 

Thanks

 

Debra

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