Hi to all FeFlow users !
As I'm a new Feflow user, I need to discuss about the way to build a model with FeFlow, allowing to simulate a particular case : a chalk aquifer unconfined in one area, then becoming confined under a impermable formation.
I join an attached image to correctly describe the geometry of my problem. My main questions are :
- what's the best way to represent under FeFlow the red impermeable formation, existing only in one part of the total domain ? In the area where the chalk aquifer is unconfined, should I specify a very low thickness for this red layer, and give it the same caracteristics of the underlaying chalk layer ?
- in the free+surfaces editor, what option should I select for the confined part of the chalk aquifer ? And in the unconfined part ? Another constraint for the model is that in the confined part, some pumping wells induce drawdown of piezomteric surface, making the groundwater locally "unconfined" (water level locally lower than the bottom of the red recovering impermeable formation)
Note that the above questions are also relevant for the sandy aquifer (green on the drawing), unconfined in a very narrow area, then also becoming confined...
Any help will be appreciated !
Fabrice