• Re: I cannot email "support@dhi-wasy.de"

    Hi Morgan,

    Since already a year ago, DHI-WASY has moved its official FEFLOW support address to mikebydhi.de@dhigroup.com. Please try using this email address. If the problem persists, let us know.

    Best regards,
  • Re: Particle movement in unsaturated zone

    Dear Dan,

    I would not say that there is not water... Although the first five layers are above the phreatic level, you have imposed a residual water in the Problem Settings dialog. Particle tracking is calculated based on Darcy velocities, therefore only if the lateral velocity is negligible the flow as well.
    It seems to me (without knowing layer thickness) that you may have a considerable unsaturated zone. You may try the Richards approach for a better approximation of the fluxes in the vadose zone.

    Best regards,
  • Re: Problem: FePest do not optimize more than one parameter groups simultaneously

    Dear Sven,

    Did you check if the parameter definitions are set as either [color=red][b]none [/b][/color] or [color=red][b]log[/b][/color] (in Default section)? The definition "none" refers that parameter will be adjusted by using its default units (not transformation at all). If a parameter group is set as [color=red][b]"fixed"[/b][/color], this will not be adjusted during the optimization.

    There are parameters (e.g. conductivity, transmissivity, etc.) which are easily adjusted by using a log-transformation. [color=blue][i]"Often a proper choice of whether and what parameters should be logarithmically transformed has a pronounced effect on optimisation efficiency; the transformation of some parameters may turn a highly nonlinear problem into a reasonably linear one"[/i] [/color](PEST Manual, 1-8). If we are talking about a coupled process (flow-heat), a high degree of non-linearity is inherent in the problem.

    In general, the "standard" (or default) settings need to be reviewed by the modeller. Several of these settings have been taken from the PEST manual, however there may be cases where they are not applicable for all the models.

    Best regards,
  • Re: Null space Monte Carlo with FePest?

    Dear Sara,

    Coincidentally, this was one of our topics last week in the FePEST Training course in Vancouver :-).

    Indeed, you could carry out the task of Null Space Monte Carlo with FePEST. However, we need few steps in the command line still.
    I could suggest the following workflow:

    1) Set-up your project in FePEST and include all the slaves definitions already. Notice that PEST documentation recommends to avoid regularization settings for the Null Space Monte Carlo.

    2) Go to Estimation - Open work folder in console window.

    3) Run PEST utilities named [b]RANDPAR[/b] and [b]PNULPAR[/b]. They are very easy to use, you could take a look on the PEST documentation about this. The results from this utilities will be a set of parameter files (*.PAR). The total number of files depends on the number of realizations indicated. RANDPAR creates random parameter distributions and PNULPAR sub-divides the random realizations in calibration space and null space. So what you get here is a set of "almost calibrated" parameters.

    4) Now the difficult task is to run each parameter realization. Since these PNULPAR-generated parameters are [i]"almost calibrated"[/i], you may need to one or two PEST iteration cycles.

    5) Sometimes even a more simplified way, it would be to run one single model run per realization. If this is the case, FePEST can help you directly from the graphical interface to launch all the mode runs together with BeoPEST. This is only possible if you use the new PEST version 13.2, which contains a special /f-switch. This PEST version is not still distributed with PEST Utilities package from our website, but you could look on the pest homepage website.

    If additional details are needed, I will try to post a most extensive description.


  • Re: Implementation of local groundwater infiltration

    Dear Mandy,

    If you are using a material property to provide the infiltration, FEFLOW will take as temperature the reference value imposed in the Problem Settings.
    Instead, you could combine a Fluid-Flux BC for the flow part and Temperature BC for the heat part. In a confined aquifer, the Fluid-Flux BC is expressed in m2/d.


  • Re: Ttime-series and current expression boundary condition

    Dear all,

    Here I have couple of ideas/comments:

    @ Lucien,
    If the answer is not constraint, you would need to write a short plug-in to control the BCs depending on specific variables.

    @ Marc,
    - The Head BC should be always available during the model run. I think the answer is not an expression, you need an interpolation between two nodes with an assigned time-series. You can easily carry out this task by using the 1D Linear Interpolation interactive tool. You need to impose strategically time-series in important locations, and then interpolate in between.
    - The Mass BC could be assigned already at the beginning of the simulation. The mass BC should be active if there is inflow from the sea to the aquifer. Otherwise, the mass concentration at the boundary nodes is not anymore imposed and it is the computed. You can control this behavior easily by means of a constraint (e.g. minimum hydraulic head).
    - The most important point is not to forget the conversion from saltwater heads to equivalent freshwater heads. Such transformation is based on the density ratio in FEFLOW.

    Good luck!

  • Re: Add or remove servers / slaves during a pest run

    Hi Jarrah,

    Indeed, you can edit the slave set up during the PEST run. In the server you just need to go to the folder, where the slaves have been deployed. By default, they are placed on a temporal folder under \fepest_data\. You can find the temporal folder if you type %temp% in Windows Explorer.

    [u][b]Include new slaves in the FePEST parallel run:[/b][/u]
    - Make a copy of the slave folder. Typically they are named as "[color=red]FePEST ProjectName[/color] [b]@[/b] [color=purple]ServerName[/color] [b]~[/b] [color=green]SlaveNumber[/color]" (everything together).
    - Edit the folder name and increase the slave number.
    - Go inside the new created folder and execute file [color=red]run_slave.bat[/color].
    - A command window is opened and model starts running.

    [u][b]You can also attach new servers not described before FePEST run was initiated:[/b][/u]
    - Copy the slave folder from any server (or even from a local slave in the FePEST Master).
    - Edit batch file [color=red]run_model.bat[/color].
          a) Define (if needed) the location of the fepest62.exe (Typically C:\Program Files\WASY\FEFLOW 6.2\bin64).
          b) Define the location of the FPS file.

    - Edit batch file [color=red]run_slave.bat[/color].
          a) Define (if needed) PEST path. Typically "C:\Program Files\PEST Utilities\pest\"
          b) Define location of BeoPEST and PST file.
              "C:\Program Files\PEST Utilities\pest\beopest64.exe" "MyProjectName.pst"
          c) Define FePEST Master name (or IP address) and the port defined previously for connection (This was already set in the FPS file).
              /H MyIPnumber:MyPortNumber

    [u][b]Reduce the number of slaves in the FePEST parallel run:[/b][/u]
    - Go to the slave folder in the server.
    - Execute file [color=red]stop_pest.bat[/color].
    - A command window is opened and it will requires to confirm the action.



  • Re: Correlation length?

    Dear Joachim,

    Indeed there are many changes in the FePEST version 6.2, especially the regularization settings and interpolation techniques (e.g. Kriging) are different. This is because [i][b]they need to be adapted to specific case studies[/b][/i]. For example, a "typical" misunderstanding is that variogram parameters are applicable for all the models and all parameter types. You may take a look on Geostatistical books to review the different methods for empirical variogram fitting, you will notice that these parameters depends a lot on sampling design, parameter types (conductivity, transmissivity, porosity, etc.). Therefore, FePEST cannot suggest values on which the modeller has the responsibility.

    You may take a look in the following settings in FePEST version 6.2:

    1) Kriging configuration (variogram type, range, nugget, etc.).

    2) Tikhonov regularization settings (Objective function, weight factor and weight adjustment). These options were not available in FePEST Beta version. Especially, objective function values can control strongly the balance between observation over-fitting and/or adequate (or geologically-realistic) parameter distributions.

    3) SVD regularization: Adjust number super parameters (Default value is zero).


  • Re: Ttime-series and current expression boundary condition

    Dear Lucien,

    What you need to use is a boundary condition constraint (BCC). These can swtich on/off the BC depending on certain criteria (e.g. min/max hydraulic head and min/max flow-rate). Constraints are applicable for flow, mass, heat and age problem classes in FEFLOW 6.2. You can also have time series of constraint.
    You may take a look in the Help System or in the White Papers Vol. I.


  • Re: Correlation length?

    Dear Joachim,

    Please notice that FePEST 6.1 was a quasi beta version compared to FePEST 6.2, which is fully developed. I strongly recommend you to use 6.2 version.
    What exactly would you like to do? Could you be more especific in what kind of regularization setings you need to chance?