Boundary condition setup

Hi,

PFA the bathymetry and the MIKE 21 result file.

I have created this bathymetry using DEM data.

I have time varying .dfs0 files of discharge and water level at all open boundaries.

I am using the program detected boundary points. I have also attached the .m21 log file, to follow the simulation settings.

The final result that I get is with depth value as 0 at all points. I guess its the boundary editor setup where i have messed up, and need an advice on that.

Hi,

please make sure, that your inflow boundary is wetted at the beginning of the simulation.
MIKE21 needs wetted inflow boundaries.

You can do that by setting appropriate initial conditions.

Bests Christian

Hi Christian,

Wetted initial boundary condition means??

The water depth in all boundary points should be >0 at all times, including in the initial condition.

Best regards,
Poul Kronborg

Thanks for the reply Paul, but am guessing that, being a first time user, am unable to understand the setup procedure.

Steps Followed are-

1. Convert Dem to .dfs2 format.
2. Open the file in grid viewer, edit items, change the type to Bathymetry.
Doubt -1 : What should be land value?? the elevation values vary from 700 to 12m
3. Anyhow, I gave a value of 30, as per my understanding, all the values above 30 will be considered as land values.
4. In the MIKE21 set up file, at the boundary conditions options, the coordinates of boundary box is detected. , Now I have point source discharge values at upstream, downstream and at the tributary, if you can follow the figure in post 1.
5. The setup runs without error, but the result is empty :(

Hi again,

It's difficult to see what's happening in your model, but I would give you the following advice:

1. You have to have a close look at that bathymetry to see if it actually comes out with values that are correct after your interpolation/manipulation. It seems that you get no results because there is no water in the model and that is probably because your boundary values don't fit with the bathymetry.

2. You should also have a look at the boundaries. The automatice detection finds 8 boundaries, that is probably not the easiest solution for this case, my guess is you should reduce that to 2-4.

3. Land value should be a level that you evaluate will not get flooded.

Best regards,

Poul Kronborg