• Import elevation data in .asc


    I have elevation data given in a .asc file, and I would like to import it to use it to apply elevation on my model.
    Is it possible to import directly a .asc file in Feflow ?

    thank you for response
  • Re: Storage compressibility parameter in unsaturated flow ???


    I thought it would be that. But I am wondering about the strong influence of this storage compressibility parameter on the results. I did parametrical tests and this parameter seems to be very important. Now, how should I manage to calibrate my model ?. Modifiying the storage compressibility results in a change of the global behavior ( more little it is set more nervious is the system)... I can also reproduce it with the porosity. So should I consider this parameter, or simulate this unsaturated system with the default values ?
    Now the default values are 10-4, much to small for an unsaturated system !!!

  • Storage compressibility parameter in unsaturated flow ???


    I have a question concerning simulations in unsaturated media.

    In the parameters it can be seen that in the unsaturated  type of problem it is still possible to enter a storage compressibility value. I am wondering about the effects of this parameter ? as I thought that in unsaturated runs it is only the porosity that should play  this role. So what is the meaning of this storage compressibility parameter in unsaturated models. How does it interact with the porosity ?

    Thanks for all

  • Phreatic surface for unconfined aquifer


    I have some questions concerning the unconfined properties.

    In which case do we use the free&movable or the phreatic options ?

    As the phreatic option is considering, depending on the hydraulic heads, a unsaturated zone, can we use this option instead the unsaturated one ?
    In other words, if we know that the aquifer water table is 10m deep for instance, and that we ignore everything about the unsaturated zone, can we use the unconfined phreatic option.

    What are the limits (hydrogeologic cases) that we should not use it ?

    I would like to simulate heat transport, with surface temperature boundaries and top infiltrations, is this option (phreatic) usable ?

    Thanks for the responses

  • Re: Unsaturated flow - flow boundaries (flux)

    Hello Volker,

    Effectively I was thinking about this ... It is an eleven layers model. With a thickness of one or two meter on the border where the conditions are imposed. Maybe should I think to get larger elements. Also my influx are time varying. The variation is quite huge.

  • Re: Unsaturated flow - flow boundaries (flux)

    Thank you Peter for your fast reply.

    I have checked the model, and when switching it in the saturated confined form, the boundaries conditions are respected and the solution very stable. Now, my model is an highly low-permeability heterogeneous one. K-field parameters are distribuated between 1E-5 and 1E-8 m/s.
    The porosity (unsaturated parameter) is also set as heterogeneous, and very low [0.05 and 0.09].
    The initial pressures are ranged between : - 0.1 PSI and  + 1.0
    The saturations from 0.06 to 1 --- the model is highly unsaturated (~ 1/3 )

    Should I used instead the default Neumann Conditions the Gradient-type conditions ?
    Maybe Can I perfom changes in the unsaturated settings using the Mixed head-saturation form or variable substitution form ?

    Thanks for reply

  • Unsaturated flow - flow boundaries (flux)


    I have a question related to the flux boundaries conditions in unsaturated flow. I have performed a 3D unsaturated model, with lateral flux boundary ( inflow ). After simulation when I am checking the budget analyser, I notify that water is also going out of these boundaries ?!? ... The simulation results are not respecting the boundary restrictions ? why does water coming out, when inflow boundaries are imposed ? How can I manage it ?

    I used the default parameters for calculation : Richard Head-based standart form, and so on ...

    Thank you for your help.