heads above the water table in phreatic mode

Some questions:
- How to interpret heads calculated above water table level in Feflow/Phreatic mode ? What is the best way to plot the water table contours ?
- How is simulated the unsaturated zone above the water table in Phreatic mode, and how is the in/out flow transmit from the ground to the water table ?
Thanks !
Didier

Hi Didier,  FEFLOW maintains a minimum saturated thickness (0.01 meters?) in all elements because there is no such thing as a no-flow cell like in MODFLOW.  The in/out flow on top is applied the top layer of the model no matter what mode is used.  This can cause problems in the simulation if the layers vary in elevation much more than the observed water table.  If you have to model such elevational changes, such as in a mountainous region, I recommend using 3D variably-saturated mode instead of phreatic.  If you chose to use this mode, you will have to specify unsaturated properties that are compatible with your model setup.

Pete

Thanks Pete
So if the Top/bottom flow is applied to the top layer, even if this one is dried, does Feflow apply a delay function to transfer the flow from the ground to the water table surface ?

FEFLOW does not apply a delay function, but as in Phreatic mode the conductivities in the dry layers are reduced by a factor of residual water depth/layer thickness, there will be a delay resulting from the low conductivity.