This tutorial gives a brief introduction to a more advanced Pumping Tool which serves to simulate new features within an existing model configuration. It is advised to get familiar with section 11.7 that handles the most regular model simulation. See for more detailed references regarding the Pumping Tool section 7.11.
This is what you will do:
• Take the minimum number of necessary steps to start the Pumping Tool;
• Constructing a dewatering system of vertical extraction wells;
• Include observation wells;
• Start a model simulation and analyse the results;
• Saving your configuration.
For this tutorial you need the following iMOD Data Files/folders:
• The entire folder (and subfolders) in {tutorialfolder} \TUT_MODEL_SIMULATION (see section 11.7 for more information about these folders/files)
• The entire folder (and subfolders) in {tutorialfolder} \TUT_PUMPING_TOOL, containing:
– ADD_TO_IMOD_INIT.PRF – supplies an additional KEYWORD for the preference file for iMOD;
– PUMPINGTOOL.INI – an initialization file for the Pumping Tool;
– MODEL.PRJ – configuration project file that describe an autumn situation;
– Files in the folder {tutorialfolder}\TUT_PUMPING_TOOL\TOPBOTTOM for the top- (TOP{i}.IDF) and bottom (BOT{i}.IDF) of model layers. It also contains the initial phreatic head in HEAD_STEADY-STATE_L1.IDF.
– Files EXTRACTIONRATES.CSV, FILTERPOSITIONS.CSV, MEASUREMENT representing the rates of the extraction of the entire dewatering system, the horizontal and vertical layout of the individual filters and the observations of phreatic heads (synthetic), respectively.
Note: {installfolder} refers to the full path of the directory you installed iMOD in (e.g. D:\iMOD).
1. Launch iMOD, and start with “Create a new iMOD Project”.
2. Go to View in the menu bar and select the iMOD Manager (or use the short-key Ctrl+M).
Quite often it is necessary to display a map for orientation. In this example we use the initial computed phreatic groundwater head located in the folder {tutorialfolder}\TUT_PUMPING_TOOL\TOPBOTTOM \HEAD_STEADY-STATE_L1.IDF.
3. Click the Open IDF button (
) from the Maps tabs on the iMOD Manager. Select {tutorialfolder}\TUT_PUMPING_TOOL\TOPBOTTOM \HEAD_STEADY-STATE_L1.IDF file in the Open IDF File window and click the Open button.
4. Click the Zoom Full button (
) to set the zoom extent to the full extent of the selected IDF-files.
5. Go to Toolbox in the main menu bar and select the Pumping Tool.
Figure 11.173: Start of the Pumping Tool.
Note: As long as the Pumping Tool window is active it is possible to use most of the general functionalities of iMOD. Be aware that entering e.g. the Cross-section Tool, the 3-D Tool closes the Pumping Tool.
Let us construct a simple dewatering system that consists of 5 extraction wells along a single strip.
6. Click the Add Well System button (
) on the Well Systems (0) tab. The ‘(0)’ means that there are no well systems defined yet, which is indeed the case.
In the Well Systems window, you can define how the dewatering system (or some equivalent, e.g. Aquifer Recovery System (ARS), Aquifer Thermal Storage (ATS)) is configured. You can specify for each date an extraction rate; alternatively, you can read a comma-separated-values file with that information. Let’s do that.
7. Click the Open File button (
) and select the file EXTRACTIONRATES.CSV from the folder {tutorialfolder}\TUT_PUMPING_TOOL.
The EXTRACTIONRATES.CSV file itself contains one descriptive header and two columns; column one stores the date (yyyymmdd) and column two the extraction rate (m\({}^{3}\)/hr), see below the content of the file:
date[yyyymmdd],q[m/hr]
20110918, -10.0000000
20110923, -25.0000000
20110928, -50.0000000
20111008,-125.0000000
20111023, -60.0000000
20111028, -10.0000000
20111102, 0.0000000
20111107,-999.0000000
iMOD will read the data and put it in the table adding 2 more columns; Duration and Julian date. Be ware that the last entry of -999.0 is irrelevant, iMOD is ignoring the Q-entry or the last record. Let’s make a graph of the extraction rate.
8. Click the Graph button (
) to display a graph of the evolution of the extraction rates in time.
9. Try the different functionalities that are on the Graph window, e.g. zooming functionalities, see section 6.6.1 for further reference to this window.
Figure 11.174: Example of the entered well strength.
Each extraction rate is defined by its starting date, therefore a bar is drawn from that moment until another rate is specified. Let’s define the filter positions.
10. Click the Close button on the Graph window to close this window.
11. Select the Positions of Filter tab on the Well Systems window.
12. Instead of entering all positions manually or graphically, we’re going to read those positions from a predefined file, called FILTERPOSITIONS.CSV. Click the Open File button (
) and select that file from the folder {tutorialfolder}\TUT_PUMPING_TOOL. As a result, 5 extraction wells are displayed in the main graphical window of iMOD.
13. Zoom in to the location of the wells to inspect the layout. Just use the regular zoom functionalities on the main toolbar of iMOD.
Figure 11.175: Example of the entered well filter screens.
The FILTERPOSITIONS.CSV file contains for each extraction filter, its label (e.g. Well 1), vertical position (top and bottom of the screen) and its horizontal position (x,y coordinates), see below for the content of the file.
label,z1,z2,x,y
‘Well 1’, 0.00, -2.50,145732.28,448621.03
‘Well 2’, 0.00, -2.50,145667.50,448673.47
‘Well 3’, -5.00,-10.00,145608.89,448725.91
‘Well 4’, -5.00,-10.00,145550.28,448778.34
‘Well 5’,-15.00,-20.00,145491.69,448821.53
iMOD assigns the well to the appropriate model layers automatically. Moreover, as this well system consists out of multiple wells, the strength that we just assigned is distributed over the different wells (1 up to 5) according their sum of transmissivity along the individual well screens.
14. Click the Close .. button to leave the Well Systems window.
15. Click the Yes button to save your adjustments.
16. Experiment with the options by Plot Information on the Well Systems(1) tab. See, how these change the visualization of the well systems and their attributes.
17. Click the Save As button (
) on top of the Pumping Tool window (section Scenario Project) to save the configuration on disk. Place your configuration in a folder to be created (IMOD_USER\PUMPINGTOOL) and name it DEWATERING.ISF.
18. Click the OK button to confirm.
The file is editable by e.g. NotePad, although it is not advisable to change the file outside iMOD.
Not much else is needed to start a model simulation.
Figure 11.176: Example of the Results tab.
The Compute Result(s) window shows the most important settings that can be changed before a simulation starts. These are very limited, compared to the settings that can be changed in the Model Tool (see section 7.9). In this tutorial we experiment with a model configuration for an Autumn Situation.
21. Select the Model Situation configuration and click the Check PRJ file Configuration button (
) to examine whether all files are available.
There will be a window opened that contains the following information.
Check-result for:
{installfolder}\TUTORIALS\TUT_PUMPING_TOOL\MODEL.PRJ
Non-existing files:
Line No. Filename
————————————————–
All files exist !!!
So, this means everything is okay, we’re ready to go.
22. Close the text-window via the option File and than the option Exit from the main menu bar on the text editor window.
23. Select the options Phreatic Heads (this one is compulsory!) and Drawdown (computes draw down in each model layer for each stress period) from the Simulation Results menu list.
Figure 11.177: Example of the Compute Results window.
The current model simulation consists of one initial steady-state simulation and 9 intermediate stress periods. The distribution of stress periods is defined automatically by the occurrences of extraction rates. The cell size of the model is 25 meter and around the maximal extent of the set of wells, a buffer is included of 1500 meter.
24. Click the Start button.
25. Confirm the simulation by clicking the OK button.
iMOD will create a PRJ file in the same (results) folder where you saved the file dewatering.isf earlier. In this case it will be {IMOD_USER} \PUMPINGTOOL \DEWATERING \
V1_MODELSITUATION \MODEL.PRJ (i.e. the actual and modified model configuration) that consists of the extraction wells of the dewatering system as well. iMOD computes the strength for each of the individual wells and assigns them to the appropriate model layer based upon their screen depths. These will be saved in a separate IPF files {IMOD_USER} \PUMPINGTOOL \DEWATERING \V1_MODELSITUATION \WELLS \WELL*.IPF. Afterwards you can (re) uses those files for visualization and/or direct use in another PRJ of RUN file. Finally, iMOD creates a MF2005 structure and runs the model(s).
26. After the simulation ends, select the option V1_MODELSITUATION from the Available Results list and click the Contour button (
) to start the Quick Open window, see section 6.2.
27. Select the item [DRAWDOWN] from the Topic list.
28. Select the time [20111102] from the Time list.
29. Select model layers [1] up to [8] from the Layer list.
30. Select the option Display.
31. Click the Open button.
Figure 11.178: Example of the Drawdown results for the entered pumping regime at 2\(^{\rm nd}\) of November 2011.
iMOD will open the selected IDF-file in the iMOD Manager (see section 5.4). It is advisable to check the extent of the drawdown for each model layer to see whether the applied buffersize is appropriate. In other words, the drawdown may not reach the boundary of the model area significantly.
32. Select all IDF-files (DRAWDOWN*.IDF) from the iMOD Manager and use the Map Value Inspector (
) from the iMOD Manager to inspect the drawdown throughout the model. The maximum drawdown at the boundary of the model is acceptable for the entire modelling domain.
33. Use the TimeSeries Tool (see section 7.2 and section 11.4) to observe the time variant behavior of the drawdown throughout the model.
Let us add an observation wells that was measured during the dewatering.
34. Select the Observation Well (0) tab and click the Add Observation (
) button.
35. Change the Observation Name into [Observation 1].
36. Click the Open CSV button (
) and select the file MEASUREMENT.CSV from the
TUT_Pumping_TOOL folder.
37. Click the Graph button (
) to display the time series of the measurement.
38. Click the Close button to close the Graph window.
Let us define the horizontal and vertical position of the current observation.
39. Click the Position of Filters tab.
40. Click the Add Filter button (
).
41. Move your mouse on the graphical canvas and position the observation as close as you can near the coordinates: [x=145650; y=448725]. Read the current coordinates of your mouse position on the lower left corner of the graphical canvas.
42. Press the left mouse button when you are satisfied. You can always change the coordinates manually in the Position of Filters tab.
43. Change the vertical position of the observation screen in [top=2.5; bottom=1.5].
Figure 11.179: Example of the Time series of the added observation.
Read section 7.11.3 for more detailed information about adding and changing observation wells. Now we have added an observation wells that we can use to evaluate our model performance.
45. Select the Results(1) tab from the Pumping Tool window.
46. Select one or any simulation results from the list.
If you select more simulation results, you will be able to analyse the behaviour of different variants of your dewatering systems.
47. Click the Graph button (
). It was greyed-out before, since there were no observations defined.
iMOD will generate a time series for all observations which can be inspected separately in the next steps. The entered top- and bottom elevation for the observation determining what model layer need to be used to generate the time series.
Figure 11.180: Example of the Time series of the added observation and the simulated groundwater levels.
48. Click the dropdown menu on the top-right of the Graph window to switch between the observations [Observation A] and [Observation B].
The entire project is saved in a ISF file which is easy to read and/or modify outside iMOD. Below is the example of the ISF file that we just created.
1
“Well Field 1”
7,1,20110918
5,-10.00
5,-25.00
10,-50.00
15,-125.00
5,-60.00
5,-10.00
5,0.00
5,1,28,255
“Well 1”,0.000,-2.500,145732.280,448621.030
“Well 2”,0.000,-2.500,145667.500,448673.470
“Well 3”,-5.000,-10.000,145608.890,448725.910
“Well 4”,-5.000,-10.000,145550.280,448778.340
“Well 5”,-15.000,-20.000,145491.690,448821.530
1
“Observation 1”
8
20110913,1.790
20110918,1.686
20110923,1.662
20110928,1.488
20111008,1.433
20111023,1.416
20111028,1.460
20111102,1.584
1,1,7,255
“1”,2.500,1.500,145650.000,448725.000
