• Re: Problem with Fluid-flux BC (unsaturated model)

    Hello Carlos,

    Thank you it's clear and it's work, so perfect !  ;)

    Thanks again and sorry for the late response

  • Problem with Fluid-flux BC (unsaturated model)

    Hello everyone,

    I have some troubles with my unsaturated model but I can not figure where is my mistake.

    I'm modeling a simple 2D ground column (1*0.3 m) with only 2 boundary conditions : a fluid-flux BC on the top (very low, 1mm/y) and a hydraulic head below (0 m).
    I correctly enter the different parameters for Van Genuchten's law and run it for 10 days.

    [b]But when I look the Period budget it seems that my fluid-flux BC is not correctly met and to much water is entering on it. [/b]
    The problem is really link to unsaturated because if I swicht to satured the same condition is fulfilled.

    Have you an idea of what to do to be sure that my fluid-flux BC is correctly enter and met ?

    Thanks a lot  ;)

    Ps : I'm using FeFlow 7.0
  • Re: Which slice for hydraulic head BC ? (Multilayer model)

    [quote author=Peter Schätzl link=topic=21856.msg28804#msg28804 date=1582122270]
    Indeed the way of thinking is a bit different in between MODFLOW and FEFLOW... There's no unique answer to your question, but in a general system of aquifers and aquitards I'd put the aquifer head bcs to both top and bottom of the aquifer. If there's no clear separation, but rather a system of layers of slightly differing hydraulic conductivities, I'd typically tend to use the condition of the higher conductive layer a slice belongs to. And - yes - I'd also put a BC to the bottom layer.
    In all cases you should keep in mind where your BC data come from to judge where to best put them. In an ideal world, vertical discretization would be fine enough to render the influence of the slices separating the geological units negligible - but the world (or the model) is never ideal as we all know.

    Okay I understand better now, and yes always keep in mind where the data come from...
    Thank you very much for this clear and quick answer, it is very useful to me !
  • Which slice for hydraulic head BC ? (Multilayer model)

    Hi everybody,

    I've some questions and I would be very grateful for some explanations !

    I’m modeling a multilayer fully confined model (for each layer, different porosity, conductivity, etc) and I need to input the hydraulic-head boundary conditions (also different for each layer).
    So my question is simple: on which slice should I implement the hydraulic-head boundary conditions : Top of the layer, bottom of the layer, both ? And for the final slice, should I put boundary conditions to ?

    I think that’s a begginner's question but (unfortunatly ?) I was a ModFlow user before so for the moment I can not figure out the slice’s phylosophy of FeFlow !

    Thanks a lot  ;)

    Ps : I'm using FeFlow 7.0