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  1. Today
  2. Observations in MODFLOW-USG

    Boy, you want us to actually read the documentation? Thanks - I was actually hoping that you could point me to something like that!
  3. Observations in MODFLOW-USG

    They work differently in USG because there is no OBS package. See this tutorial for more info: http://gmstutorials-10.3.aquaveo.com/MODFLOW-USG-Calibration.pdf
  4. Yesterday
  5. Problems With Pressure BC

    SRH-2D pressure flow structures are different than the other SRH-2D structures. For weirs, culverts, and gates it used to be recommended that you leave the materials for area between the structure arcs "unassigned", that is something that has recently changed. SRH-2D now will inactivate these areas when it runs the model, which is one less thing we have to try and remember to do now. Pressure flow structures actually need a material assigned to them because the area between the structure arcs (bridge deck) never gets unassigned. The 2D simulation results are computed in that area and represent the flow beneath the bridge deck. Try assigning a channel roughness to the polygon beneath the bridge and everything should run correctly. -Cody
  6. Observations in MODFLOW-USG

    At one point during my current project (a transient MODFLOW-USG simulation), I was attempting to create observation points to make some plots. It didn't seem to be working. I know that I've had some minor issues in the past getting the observations to work correctly, so I didn't think too much of it and got the info I needed in another way. However, I found myself with a little time today and figured that I would look into it a bit more. I pulled up an old model where I had a transient simulation to see if I had done anything different (I did not). I then ran my model using MODFLOW-2005 (after removing USG-specific stuff) and even though I didn't converge, the observations points appear to have worked. Are observations not set up to work in MODFLOW-USG?
  7. Problems With Pressure BC

    Hi everyone, I am having problems with my pressure Boundary Conditions (BC), for some reason the water will not flow through the BC that I have made. Though everything is set up for it, the materials are not assigned in the mesh areas of the bridge, the BCs are on the proper ends and are resting on the mesh netting edges, and I have checked the elevations for the area many times in both the mesh and the BC settings. Does anyone have a clue why it is not functioning properly. If so please let me know. Thanks!
  8. transient recharge

    This looks like a bug. Can you contact support@aquaveo.com so we can look at your project and fix the issue.
  9. Fixed pilot points in PEST NSMC

    Do you know what the error condition is that prevents PAR2SEN from working?
  10. Last week
  11. transient recharge

    Hi, when converting a steady state model to transient I initialize the stress periods and import transient boundary conditions via MAP to MODFLOW. This seems to work. But for Recharge the following error occurs when looking at RCH or RCH rate: Within the properties of RCH rate all stress periods seem to be in the right format (identical to what has been defined under "Global options - stress periods" and same as for other boundary conditions like transient pumping rates e.g.). Can you help? Am using version 10.3 Mark
  12. Fixed pilot points in PEST NSMC

    I just tested the model again without parallel PEST and got the same error message: "pest has stopped working". I get this when I make a parameter estimation run with noptmax = -2. I also got this error message when from this run: The whole process before seems to work fine
  13. Diverting a Drainage Path

    By the way - a couple other important points to this topic that others might find useful: 1. When we were running WMS on a 10 metre pixel DEM there were NONE of these issues. Culverts, flow patterns and drainages all came out exactly as expected. It wasn't until we tried to refine the data by tightening up the resolution that the problems appeared. 2. When I used the ArcGIS Hydrology toolset to derive the Flow Direction and Accumulation surfaces there were no problems with the result at either 2m or 10m. The flow went through at culverts just the way you would expect... and originally, when running the data at 10m, I had used this approach rather than using TOPAZ to calculate Direction/Accumulation within WMS. No real reason why I chose that - it was just due to my familiarity as a GIS Tech with the ESRI dialog. However, when I switch up to 2m resolution, and ran the Direction and Accumulation in ArcGIS, they wouldn't import correctly into WMS. No matter what dataset I was working on - if it was 2m resolution - the WMS result from import was incomplete. The drainage patterns would look fine for about 1/2 of the area in question and then would just stop. Almost as if it was processing from top-down and hit a maximum number of values, or was tanking out on memory or computations... Below is a screen cap of the stopping line. You can see the hanging flow lines left when the import seems to have just 'stopped'. Hope it's useful, Mike
  14. Diverting a Drainage Path

    Hi, Just reporting back on my flow pattern issue. Editing the DEM as described worked perfectly, transferring the water across the road, but in the end I had to come at the problem a different way. Cody's method was convenient and straightforward but in my dataset I just had too many 'misdirections' to make it feasible. Instead I experimented with widening the gap in my roads. Initially the culvert location was a single pixel hole in the road's berm. I created a depression around this gap (trying various diameters up to 22 metres wide) to pull the water toward the culvert, it just wouldn't go through when TOPAZ ran. However, when I widened the gap in the road to be 10m (5 pixels) and kept the surrounding collection zone to 10m, then TOPAZ was able to send the water through without issue. This approach will make it easy to repeat the calculation in a consistent fashion should I ever have to go back and adjust values for climate change, etc. Below is a screen cap of the widened gap and 10 metre depression. Thanks again Gentlemen.
  15. Multilayer model calibration

    Thank you so much Alan! Today i've completed the pilot points tutorial and think i found a way. I'll try also this tutorial. At this moment my biggest problem is my model convergence. I cant make it converge using field data for HK and RCH... Nonetheless i'll keep trying Thank you again
  16. Fixed pilot points in PEST NSMC

    So the tutorial seems to work fine with fixed points. I just tried it again this morning. Does PEST report any errors? Perhaps it is a bug in parallel PEST.
  17. Multilayer model calibration

    Try this tutorial: http://gmstutorials-10.3.aquaveo.com/MODFLOW-TransientCalibrationPumpTest.pdf Multi-layer and transient.
  18. Multilayer model calibration

    Hello everyone! I'm building a multilayer model with GMS (MODFLOW-USG) for a region in Portugal and i start the calibration fase. Can anyone tell me the best way to calibrate my model? I'm thinking about to using the pilot point method, but i cant find a tutorial on how to proceed for calibration of multilayer models... Can anyone help me? Thanks in advance
  19. Fixed pilot points in PEST NSMC

    I tried both the nightly build and the latest update (10.3.4) but received this error message: The model works fine in NSMC with the NWT solver without fixed PP. Any ideas on how to solve the issue? Kind regards, Jonas
  20. Earlier
  21. 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.
  22. Porosity in MODFLOW and MT3D

    I'm sorry, my last sentence was not correct . the truth is that small values of porosity result in large values of Velocity vectors magnitude.The equation for calculating ground water velocity is: V= KI/n. (Darcy’s law). V stands for "groundwater velocity," K equals the "horizontal hydraulic conductivity," I is the "horizontal hydraulic gradient," and n is the "effective porosity."
  23. 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.
  24. PEST Observation Groups

    Hi -- Wanted to see if there was a way to designate PEST observation groups directly in GMS. I have tried editing the *.pst file after it's created by GMS but with about 92,000 head observations (from multiple map coverages representing multiple model layers) it quickly becomes problematic.
  25. 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).
  26. 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.
  27. 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.
  28. Porosity in MODFLOW and MT3D

    You did not answer the above-question
  29. 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?
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