Fabrice,

I would suggest that you look at MODFLOW-SURFACT. SURFACT is a MODFLOW-based
Flow and Transport code that successfully overcomes several of the
limitations of MODFLOW and its current transport counterparts. Examples
include rewetting of drained cells, handling of pumping wells, solute mass
balance problems, numerical dispersion and oscillations, and the implicit
assumption of the negligible impact of transient flow storage effects on
transport.

SURFACT solves the fully 3-D saturated/unsaturated subsurface flow equations
or alternatively solves enhanced equations for performing unconfined
simulations to rigorously model desaturation/resaturation of aquifers.

http://www.hglsoftware.com/ResourcesLibrary/modflow-surfact.pdf

For more information, you can call Software Sales at 1-(703) 478-5186 or
info@...

Thanks,
Prashanth Khambhammettu
Water Resources Engineer
HGL


On Wed, Aug 6, 2008 at 5:38 AM, fabrice.compere <
fabrice.compere@...> wrote:

> Hi to the members of this group.
> That's my first post ever here !
>
> I'm performing a preliminary research concerning the possibility to
> modelize a chalk aquifer unconfined in its west part, then becoming
> confined in its East part.
>
> At this day, I have not found any serious reference describing such a
> problem. Obviously, I would tend to a simplistic (?) approach
> involving strong contrast in storage coefficient between the two
> areas.
>
> How to treat this type of configuration with ModFLow ?
> Does anybody knows a reference (article, book,...) dealing with this
> problem ?
>
> Thanks a lot to answer.
>
> Best regards
>
> Fabrice