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Everything posted by Michal

  1. Hi, I would like to see a functionality in GMS, that would make working with pumping data more easy. Let me make an example to explain what I mean. Consider we would like to import pumping schedule for a single well into a transient model with three periods with a length of 30 days each. The well Q for first period was -100, for second the well was off and for third it was -200. The pumping schedule extracted from a database has this format: well_name time Q well1 1 -100 well1 61 -200 I would like GMS to ask me during import, how do I want to treat the stress periods without any pumping data, in this case the second period. I would like to have an option to choose, that when there are no data for a given period GMS would add 0 for that period automaticaly, e. g. the well is off for that period. This would be realy useful, because otherwise one easily forgets to add the zeroes manualy and ends up with incorrect schedule.
  2. SFR2 not working with MODFLOW 2005

    Hi Niklas, I have encountered similar problem with MODFLOW-NWT. After an update MF-NWT started to report head below cell bottom error and a model that run ok with previous version was terminated due to this. I solved it by increasing the head slightly as it was only a very small difference. My point is that MF developers added a check module that was not in the old version and you are probably strugling with something similar. MF2K5 being smarter in finding the errors then MF2K (or the SFR2 module). As the best option of fixing the errors is not feasible, you could try looking into MF2K5 change log and maybe try to use older version of MF2K5 that may not contain the check. Or you could disable the check module in the SFR2 source code and recompile MF2K5 yourself. It is a matter of compiling MF2K5 with ICHKSTRBOT_MODULE located in gwf2sfr7.f modified accordingly. Just be aware that you may get incorrect solution as the check has its purpose.
  3. Remove Drains from Exported Transient Observations?

    Hi Carrie, you can uncheck the Enable saving of computed flows for all source/sink objects in the Output control.
  4. Problem with Null-space Monte Carlo

    Hi speedy, I have also struggled with krigging setting not saved properly. But this was solved in GMS 10.3.4. I have recently succesfuly solved inverse problem with Aquaveo MODFLOW model using PEST. There was pp kriging set up for several parameters. Although it worked ok for me , I would still prefer GMS to use native PEST tools for pp interpolation and PEST structure files for storing interpolation setting as it would allow us to use native USGS modflow for calibration with pilot points very easily. Anyway, thank you for sharing your experience on the forum. It is always very helpful. Best Michal
  5. MT3DMS THKSAT error

    Hi, mt3d is trying to read the saturated thickness array from the flow-transport link file (.hff) on unit 10. I suggest you to check that the .hff file is written correctly by modflow. It must be allowed in the GMS output control dialog.
  6. Determing boundary condition

    Hi, I think the flow could be calculated as a difference between the head in the model cell and corresponding head at the boundary. Conductance is the proportionality constant. Therefore Q = C (h1 - h2). If you know the head at the boundary (in the neighboring aquifer) and in the model cell, conductance could be easily calculated from the above formula for each model cell and the flow through the boundary would be as specified for each cell.
  7. Transient spatially distributed recharge

    Thank you for sharing the solution. Nice one Have you used some sort of interpolation to obtain modflow compatible dataset from the raster data? Or is the grid and rasters identical in number of rows and columns?
  8. Hi, try preparing the transient dataset so, that for each polygon in GMS coverage, there is a corresponding timeserie with the polygon id assigned at each row of the dataset. It will be a large dataset, but GMS should handle it unless you run out of memory.
  9. I agree with Hisham on this. There is no such concept as multipart polygon in GMS, as far as I know.
  10. Hello, this is interesting. Maybe there are 553 multipart polygons in the shapefile and when converting to feature object GMS performs multipart -> singlepart conversion. http://desktop.arcgis.com/en/arcmap/10.3/tools/data-management-toolbox/multipart-to-singlepart.htm
  11. PEST Observation Groups

    Hi Bruce, that would be very nice GMS feature. It could be even so, that head observations for different coverages would fall into different observation groups in the PEST control file. Also parameter grouping with custom naming would make thinks a lot easier. I can imagine, you could specify PEST parameter group in the Parameter dialog for each entry.
  12. Transient spatially distributed recharge

    Hi, I think it could be possible by interpolating transient TIN data (or maybe even rasters) into Recharge package using Interpolate to Modflow layers command. But I have not done it before. Let us know how you manage to handle it.
  13. Modflow 2000-transient model result

    Helo, try using MODFLOW-NWT instead of MODFLOW-2000. Its excelent in handling problems with cell drying/rewetting. In the LPF package set all layers to convertible. If insist on using MF-2000, maybe try different timestepping scheme to avoid overshoots.
  14. Hello, I am currently in the middle of parameter estimation process of transient MODFLOW model. The model has 21 stress periods. To obtain a good differentiability of model outputs with respect to parameter change convergence criteria had to be set quite strict in the NWT solver settings. This resulted in run time ranging form 30 to 75 minutes per run depending on the actual parameter set. Each stress period consists of a single time step. I was thinking, what the effect of different time stepping would be on the model run time? Would increasing the number of time steps per stress period make the model run faster or slower? Any experiences or advice on optimum time stepping with respect to model performance are welcome.
  15. Export native modflow files with Pilot Points

    Yes, this is my a workflow too. There are useful utility programs in PEST to use with pilot points, like PPKREG1 and VERTREG. The native PEST approach to pilot points is necessary to use with these programs.
  16. Hello, I have encountered a problem with exporting native modflow files from GMS. Some of the model parameters are defined using Pilot points. Lets say that I would like to use different version of MODFLOW to calibrate the model. I have succesfully exported the MODFLOW native files and I was able to start USGS version of modflow. The input data are read correctly, first stress period is solved, however during the second period MODFLOW stops. Here is the end of the output file: PERCENT DISCREPANCY = -0.03 PERCENT DISCREPANCY = -0.03 TIME SUMMARY AT END OF TIME STEP 1 IN STRESS PERIOD 1 SECONDS MINUTES HOURS DAYS YEARS ----------------------------------------------------------- TIME STEP LENGTH 2.67840E+06 44640. 744.00 31.000 8.48734E-02 STRESS PERIOD TIME 2.67840E+06 44640. 744.00 31.000 8.48734E-02 TOTAL TIME 2.67840E+06 44640. 744.00 31.000 8.48734E-02 1 1 STRESS PERIOD NO. 2, LENGTH = 29.00000 ----------------------------------------------- NUMBER OF TIME STEPS = 1 MULTIPLIER FOR DELT = 1.000 INITIAL TIME STEP SIZE = 29.00000 PARAMETER "sc1v1 " IN PARAMETER INPUT FILE HAS NOT BEEN DEFINED -- STOP EXECUTION PARAMETER "sc1v2 " IN PARAMETER INPUT FILE HAS NOT BEEN DEFINED -- STOP EXECUTION PARAMETER "sc1v3 " IN PARAMETER INPUT FILE HAS NOT BEEN DEFINED -- STOP EXECUTION PARAMETER "sc1v4 " IN PARAMETER INPUT FILE HAS NOT BEEN DEFINED -- STOP EXECUTION .... PARAMETER "GHB_3405 " IN PARAMETER INPUT FILE HAS NOT BEEN DEFINED -- STOP EXECUTION PARAMETER "GHB_3409 " IN PARAMETER INPUT FILE HAS NOT BEEN DEFINED -- STOP EXECUTION PARAMETER "GHB_3406 " IN PARAMETER INPUT FILE HAS NOT BEEN DEFINED -- STOP EXECUTION When modflow starts no interpolation is performed for the pilot points. I assume there is some custom routine in the GMS version that handles the interpolation from PP to the MF grid array. Please advice how this is supposed to be handled or what am I doing wrong.
  17. Export native modflow files with Pilot Points

    Thank you for your answer. Unfortunately this is not a solution to the problem, because you lose model parameterization. In my opinion it would be best if, when exporting native modflow files with parameters defined using pilot points, GMS writes also PEST "pilot point file" and "structure file". It could then write model BAT file with appropriate PEST utility programs involved prior modflow run, like PPK2FAC, FAC2REAL and REPARRAY. Such approach would allow parameter estimation using PEST.
  18. Fixed pilot points in PEST NSMC

    Just run from command line: pest case with case being the name of the modified PEST control file.
  19. Fixed pilot points in PEST NSMC

    Hi, no problem, you are welcome. In GMS it should be automatic, based on whether you check either Prefered homogeneous regularization or Prefered value regularization. However according to the recent experiences I strongly recommend not to do it this way. Be aware of the bug mentioned earlier regarding the usage of natural logarithm instead of decadic in GMS. I have no idea how this impacts the inversion process, but I would avoid it. If you have no log-transformed parameters, it should not be a problem, though. You can add prefered value regularization to the control file very easily by using the command line utlity from the PEST suite called ADDREG1. See the documentation to PEST (newpestman2.pdf, p. 21). It should make all the changes to the Control file necessary to run regularized inversion.
  20. Fixed pilot points in PEST NSMC

    Jonas, I have noticed, you were not running PEST in Regularization mode. That is probably the source for your error.
  21. Fixed pilot points in PEST NSMC

    Ok, thats definately a progress, PEST does not crash anymore . This is realy a weird bug, it should not crash so violently. To your new problem. Try turning SVD-Assist and Regularization off and set NOPTMAX to 0. Lets see if it works. Also try running PESTCHEK and examine the output.
  22. Fixed pilot points in PEST NSMC

    Hi, I have encountered the same error with my model. The reason why PEST and PESTCHEK crashed has something to do with the Regularization option. With Prefered homogeneous regularization option checked several empty regularization observation groups were created in the PEST control file. I believe there is something wrong with the Prior information data section in the PEST control file. After turning Regularization off or changing to it Prefered value everything runs just fine. There are three scatter point sets in my model with many parameters for different model layers. There are Totaly 18 parameters defined with PP for multiple model layers. It looks to me like some bug in writing the Prior information with such setup. Edit1: There were no fixed PP in my formulation. Edit2: There seems to be more errors. Here are some of the parameters and corresponding PI written by GMS: sc1v1 log factor 22.321 1.00000E-08 1000.0 general 1.0000 0.0000 1 sc1v2 log factor 16.947 1.00000E-08 1000.0 general 1.0000 0.0000 1 sc1v3 log factor 4.1647 1.00000E-08 1000.0 general 1.0000 0.0000 1 sc1v4 log factor 4.4251 1.00000E-08 1000.0 general 1.0000 0.0000 1 sc1v5 log factor 33.072 1.00000E-08 1000.0 general 1.0000 0.0000 1 * prior information pi0 1.0 * log(sc1v1) = 3.1055498123169 1.0 regul_1 pi1 1.0 * log(sc1v2) = 2.830082654953 1.0 regul_1 pi2 1.0 * log(sc1v3) = 1.4266545772552 1.0 regul_1 pi3 1.0 * log(sc1v4) = 1.4872899055481 1.0 regul_1 pi4 1.0 * log(sc1v5) = 3.4986937046051 1.0 regul_1 Log10(22.321) = 1.349, not 3.106 as supplied by GMS. Its the natural logarithm. However according to the PEST manual, it must be decadic:
  23. Porosity in MODFLOW and MT3D

    Hi Khaled, you are right about this. However please note, that this has nothing to do with the MODFLOW model results. There is no porosity variable involved in the governing equation of the MODFLOW mathematical model. So the values of porosity entered via the Cell Properties are used either for dataset postprocessing to calculate true flow velocity or for writing inputs for MODPATH as mentioned earlier. Now the question here is if it is also transalted from the Cell Properties to MT3DMS BTN file or not. Speedy, if this is so then it should be considered a serious bug in GMS. You can try changing the porosity in the Cell Properties dialog, save the model and look into the MT3DMS\case.btn file. Change it into something obvious like 0.666666. You should see if the array is written to the .btn file instead of the correct values specified in the MT3DMS dialog in GMS. If not sure check MT3DMS manual chapter 6.4 (Zheng and Wang 1999) for the BTN file format specs to help you locate the porosity array A11 in your file.
  24. Porosity in MODFLOW and MT3D

    This indeed looks like some GMS bug that is probably specific to certain usage. I suggest you contact the support and make sure they can replicate your problem. When you look into the Salt Lake example from GMS tutorials, you will find out that in MODFLOW>Global>Porosity dialog is not editable and correct values of porosity are entered in MT3DMS>Basic Transport Package>Porosity. In the Coastal Aquifer example the situation is different. The material properties for this example are enter using GMS Materials option in the LPF Package. The MT3DMS>Basic Transport Package>Porosity button is not present in the dialog at all. MODFLOW>Global>Porosity dialog is not editable and GMS notifies the user that materials are used in stead of arrays. Porosity is therefore specified only in the Materials dialog from which it is written to the pertinent file (BTN in this case).
  25. Porosity in MODFLOW and MT3D

    Hey Speedy, this is a good question. From Seawat User Guide (Guo, Langenvin 2002) it seems that value specified in the MT3DMS BTN Package file is the one used by Seawat.