Jump to content
GMS, SMS, and WMS User Forum


  • Content count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About speedy

  • Rank
    Senior Member

Recent Profile Visitors

1,045 profile views
  1. Problem with Null-space Monte Carlo

    Well, it seems my questions are so difficult to answer. Anyway, I have noticed many problems in kriging within GMS when using pilot points. 1) when building a variogram with data (model variogram using experimental one) these information are not saved anywhere. Every time I need to calibrate/re-calibrate I need to build the variogram again 2) when there is more than one parameter to be calibrated, the cut off values of kriging search takes always the range of the first parameter. 3) There is no way to see fitting error of experimental and model variogram to get the best fit. 4) As variogram information are not saved, after calibration you need to re-build the variogram for each paramter, which may result in a higher error than the calibration resu
  2. Problem with Null-space Monte Carlo

    Thanks for no responses I figured out the reason for these error messages. However, I found many problems in kriging in GMS, especially with calibration. I calibrated my model initially using inverse-distance method without any issue. But I had to use kriging to be able to use NSM and here all the problems appear. I defined the theoretical variogram based on experimental data but the error is huge. The other thing I was unable to click on the data truncation in the kriging menu, which is strange as this option is available when I interpolate the scatter data from scatter points menu. Moreover, PEST stops despite the error is huge when using kriging. All in all, kriging with PEST in GMS is a big headache. Anyone has any experience with this issue?
  3. Problem with Null-space Monte Carlo

    Hi again I figured out the reason behind this problem, which is the interpolation of pilot points data. I noted Null-space Monte Carlo works only with kriging! but I faced a problem with kriging. I have pilot points and selected kriging but when I try to run the calibration I have error messages shown below
  4. Hi everybody I have a model which I calibrated using PEST and SVD-Assist. The calibration was very good. When I try to run stochastic model with null space Monte Carlo then PEST runs only for one iteration and stops! I followed the exact steps in the tutorial and nothing is different. I am not sure why I got this problem. I appreciate your help. Attached is a capture of the stochastic run window Thanks
  5. Determing boundary condition

    Hi As Michal said, the best way in this case is to use General Head Boundary (GHB) but you need to know the conductance. This enable adjusting the flow during transient calculation based on the head difference. If you are looking at a steady state, you can alternatively use well boundary (injection) with the flow value you have at the boundary, so no need to know conductance. I hope this helps.
  6. Hi Mina I did change the name of the project as you advised to no avail. It seems it is a bug in GMS!
  7. Hi Fahad I did not alter pilot points. Also when I take the model files and run GMS on a different computer I do not have this problem!
  8. Hello everybody I encounter this problem from time to time with the latest version of GMS (10.3). When I run PEST parameter estimation, the runs are not shown in the MODFLOW/PEST window, despite pest is running and I can see the PEST files being updated. I am not sure why this problem occur? Any help is appreciated. Thanks
  9. Porosity in MODFLOW and MT3D

    This is true. In my case the porosity values were not editable in MODFLOW, but values were different than the one I entered in MT3D. This made all results wrong. SO I had to change the porosity values in MODFLOW. I selected all cells >right click- properties> then changed porosity values in MODFLOW. Only then the model produced correct results.
  10. Porosity in MODFLOW and MT3D

    Hi Michal After around a month of confusion (it turned me crazy) and not getting good match of the SEWAT model and analytical solution I accidentally discovered this problem. What happened is I entered the correct values of porosity using the MT3D menu not aware of the fact that the MODFLOW model assigns default value of porosity that are different from the values I entered in MT3D. While I am not sure what value the model uses in the end, but what I know for sure is the results were wrong. After I entered the correct porosity values in MODFLOW model then I got meaningful output. I hope GMS developer take into consideration this problem for future update.
  11. Porosity in MODFLOW and MT3D

    You did not answer the above-question
  12. Porosity in MODFLOW and MT3D

    Ok, then why GMS allows dupplication of entry for porosity? Why not to have it in one place (i.e. MODFLOW options) and not again in MT3D since it is essential to have MODFLOW model in all cases? Why also does GMS allows two different values to be entered for the same paramter?
  13. Porosity in MODFLOW and MT3D

    Hello everybody I noted GMS has values for porosity in both MODFLOW and MT3D. In MODFLOW menu (MODFLOW options) one can enter values for porosity, although porosity is not used in flow computations as far as I know. Also in MT3D menu it is essential to enter porosity value. In the model I have (which is a SEAWAT model) I entered values for porosity in the MT3D options, but I noticed there are different values -by default- in the MODFLOW options. Which values does the model consider in this case? and why is there an option for porosity in MODFLOW? Thanks
  14. A bug in GMS version 10.3.3

    Dear developer When viewing model result value as a table and trying to export the result to dataset.txt file, GMS crashes if the old dataset file is open in excel. It should not crash but prompt a message or something like that.
  15. Hello everybody I have a SEAWAT problem with MODFLOW/MT3DMS. Flow model works fine but MT3DMS prompts error message requiring to use sink/source term. I have no wells in the problem and the only BC are constant concentrations at both sides of the boundary. Why I need to specify sink/source terms? In this case do I need to specify negative values of ICBUND array at constant concentration cells? Thanks for help Speedy