Deph-dependant evaporation in 3D models

Hi all,

I've seen the video on how to set depth-dependant EVT in Feflow. I understand that for 3D model the same procedure must be used but in the "In/out flow on top/bottom" parameter.

With understanding purposes I've constructed a very simple square-box, homogeneus, multi-layer model where all the inflow is entering at bottom layer. outflows can occur at top layer by depth-dependent evaporation or surface seepage depending on relative BC magnitude.

Everything works fine as long as seepage occurs. As soon as I raise potential evaporation to that value where all outflow should be caused by evap (so water table should fall below ground surface) the model becomes highly unstable and heads raise to non-logical values (1.0 e+11).

Does this correspond to a highly demanding numerical simulation or there should be an easy solution and something is set wrong??

Thanks in advance!
Javier.

At the moment I would not see why this should be numerically demanding. Would it be possible to send the model for testing to support@dhi-wasy.de? My colleagues then would have a look into it, trying to find the reason for the instabilities.

I Will do it Peter. Thanks

Dear Peter,

is it possible to publicate the results of your testing in the forum, because it is extremely intersting how to simulate water level dependent evaporation in FeFlow.

Best Regards