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iMOD User Manual version 4.4 (html)


7.4Solid Tool

WHY?
The Solid Tool is an instrument that can be used to create a 3-D representation of the subsurface in which interfaces with different lithology and/or sediments can be distinguished.

WHAT?
A solid is a collection of IDF-files that describes the different geohydrological interfaces of the subsurface. Each interfaces represents a top or bottom elevation of a model layer eventually, these are saved as IDF-files (INT_L{i}.IDF and INT_L{i+1}.IDF) in the folder {IMOD_USER}\SOLIDS \{SOLIDNAME}. The IDF-files are created or updated with the Solid Tool by interpolation of the individual interfaces derived from cross-sections, points and effected by polygons and/or masks (extent) and/or individual lines (faults) and/or points.

HOW?
Select the option Toolbox from the main menu and then choose the option Solid Tool to start the Solid Tool window.

Solid Tool window, Solids tab:

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List

The Solid Tool window shows the solids saved in the folder {IMOD_USER}\SOLIDS. Click one of them to read the corresponding SOL file (see Section 9.21) and activate the different tabs.


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New
Click this button to create a new solid (see Section 7.4). A solid is a collection of IDF-files that describe the different interfaces that can serve as top and bottom elevations of a geohydrological groundwater flow model. A new solid starts by specifying the maximal amount of interfaces on the Create New Solid window.

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Select *.IDF files to be used in the SOLID
Select this option to specify IDF files from the list that need to be used as individual interfaces in the SOLID. iMOD copies or clips the selected IDF files and save them in the specified folder in which all SOLIDS are saved (i.e. {USER}\{SOLIDS}\*.IDF.

Enter single TOP and BOTTOM of SOLID
Select this option to specify a constant value (e.g. 10.0) and/or IDF file for the definition of a TOP- and BOTTOM level of the SOLID. iMOD copies or creates these files (in case of constant values) to the SOLID folder and rename them to INT_L{i}.IDF and INT_L{n}.IDF, identical to the order of the selected files. The actual number of interfaces can be entered after the OK button has been selected.

Give the name for the Solid
Enter the name of the solid, e.g. ISLAND. iMOD will create a folder called {user}\solids\ISLAND and saves the SOL file: ISLAND.SOL for more detailed information about SOL files.

Clip SOLID for the current window (all in meters)
Check the checkbox in case you want to enter an extent different from the area of the selected IDFs. Enter the coordinates for the lower left and upper right corner of the solid. Make sure that these coordinates are within the extent of the selected IDFs.

X Lower Left, Y Lower Left, X Upper RightY Upper Right
Specify the dimensions of the IDFs that will be created initially. At a later stage these dimensions can be re-specified whenever the actual interpolation of the interfaces are carried out.

CellSize:
Enter the cell size of the IDF files for the interfaces. Bear in mind that those cell sizes can be modified easily in the Compute Interfaces window. This item is compulsory whenever no IDF files are entered whenever the option Enter single TOP and BOTTOM of SOLID is selected, otherwise the IDF dimensions are use of the specified IDF files.

OK
Click this button to create the solid. Whenever the option Enter single TOP and BOTTOM of SOLID has been selected the following menu appears:

Define the number of interfaces window

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Number of interfaces
Select the number of interfaces a separate IDF file is generated. iMOD will divide the distance between the entered TOP and BOTTOM values into equal distances in the solid folder {IMOD_USER}\{SOLIDS}\{SOLIDNAME}. The SOL files describes the necessary characteristics of the solid, initial this SOL file likes like:

NINT=5
INT_L1=“INT_L1.IDF”,255,169,184,1,1,100.00
INT_L2=“INT_L2.IDF”,78,67,255,1,1,100.00
INT_L3=“INT_L3.IDF”,255,140,162,1,1,100.00
INT_L4=“INT_L4.IDF”,126,255,120,1,1,100.00
INT_L5=“INT_L5.IDF”,136,49,255,1,1,100.00

NCROSS=0

RANGE_1=5000.00
SILL_1=30.00
NUGGET_1=0.10
MINP_1=20
KTYPE_1=-2
PNTSEARCH_1=0
COINCIDENT_1=0
COINCIDENTDIST_1=10.00
IQUADRANT_1=0

After a successful completion of the creation process the following message appears

Information window.

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Help …
Click this button to start the Help functionality.

Close
Click this button to close the Create New Solid window and return to the Solid Tool window.


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Info
Click this button to open the SOL file for the selected solid in a regular text editor. It is sustained to edit the file manually, e.g. turn off some cross-section temporarily, see section Section 9.21 for more detailed information about a SOL file.


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Cross-Section Tool
Click this button to start the Cross-Section Tool (see Section 7.1) in combination with the selected Solid to create and/or edit Solid Cross-Section Files (SPF) for more detailed information about SPF files see Section 9.22.

Example of the Draw Cross-Section window, Cross-Section tab.

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List of Available Cross-sections
The cross-sections defined for the selected solid are shown here.


pictures/h5/image732.png New
Click this button to create a new cross-section. Make sure that you draw a new cross-section first using the Draw button on the Draw Cross-Section window. If not, a copy will be made of the selected cross-section in the list. The Fit Interfaces window will be started directly after, to define the name of the cross-section and enter initial settings to fit the interfaces.


pictures/h5/image733.png Delete
Click this button to delete the selected cross-section. The cross-section will be deleted from the list in the Cross-Section window. The cross-section will be deleted from the solid once you close the Cross-Section window and confirms the Question to save the (adjusted/added) cross-sections. However the cross-section SPF-file is not removed and remains available for later use.


pictures/h5/image734.png Fit Interfaces
Click this button to open the Fit Interfaces window. This window offers the possibility to start an initial guess for the interfaces in the cross-section by fitting the interfaces along the cross-section on the values read from the corresponding IDFs as mentioned and assigned to in the selected SOL-file.

Example of the Fit Interfaces window:

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Name of the Cross-Section
Specify the name of the selected cross-section; the name can not be modified once cross-sections have been defined.

Define
Check the box to define an interface line that can be modified. If this is unchecked for a particular interface, there will be no line to be edited. For a computation, the corresponding interface will not receive additional point from this cross-section.

Fit
Check the box to allow fitting of the interface of the IDF. It uses the Urs-Douglas-Peucker algorithm to fit the interface to the data of the underlying IDF files (IDF). If no IDF is present or the option is unchecked, the line will be a horizontal line with a single start- and end point.

Reset
Check the box to reset an interface line before adding additional point due to the fitting (Fit is checked). If the box is unchecked, any point due to the fitting will be added to the existing line.

IDF
Select the IDF for each an interface from the dropdown list. If no IDF is availabel the line will be a horizontal line. Each of the selected IDF files from the iMOD Manager will be present here. Note It is possible to fit on IDF files which are not direct part of the solid.

Tolerance
Enter the accuracy in meters for which an interface is fitted. A small value for the Tolerance results in an accurate representation of the selected IDF file and contains more points than whenever the Tolerance is set at a larger value.

Example of a cross-section fitted on the underlying IDF files

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Exclude
Enter the value for the IDF file which should be ignored/excluded in the fitting; this is usually (by default) the NoDataValue of the IDF files.

Apply
Click this button to start to fit each interface line to the corresponding IDF-files.

Help ...
Click this button to start the Help functionality.

Close
Click this button to close the Fit Cross-Section window and return to the Solid Tool window.


pictures/h5/image736.png Create interfaces from borehole logs
Click this button to create interfaces based on the interfaces defined in the borehole logs (IPF file) which are selected on the iMOD Manager and/or part of the solid definition, seeSection 9.21. iMOD connects each interface to the corresponding levels from the associated TXT files of the IPF file, as described below for a solid with 5 interfaces. If the boreholes has a shortage of levels, the last solid interfaces will correspond to the last level. Note iMOD does not take into account any other information from the TXT files, such as lithology.

4
2,2
z,-999
lithology,-999
0.0,S \(\leftarrow \) interface 1
-10.0,G \(\leftarrow \) interface 2
-15.0,S \(\leftarrow \) interface 3
-20.0,- \(\leftarrow \) interface 4, interface 5


Example of a cross-section fitted on the boreholes files

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pictures/h5/image737.png Lock
Click this button to lock the behaviour of each interfaces in between upper- and lower interfaces. Whenever they might cross due to a movement, they will be locked in order to avoid that they cross. Whenever two nodes are exactly on each other (which is allowed), this can prevent a movement of the node. Uncheck this button in that case to allow full editing of the interfaces.


pictures/h4/image296.png View Editable Area
Click this button to view the editable area (white) based on the extent of the entered polygons as specified on the Solid Tool window, Polygons tab. Though, interfaces can be changed outside the editable areas (these are the displayed grey areas), they will not be used in the interpolation of new interfaces. In the example below a polygon has been created for which no interpolation need to be carried out for the inside area of the polygon, those are grey coloured in the cross-section.

Example of a cross-section displaying editable areas

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pictures/h5/image525b.png Snap
Select this option to snap the selected node on the interface \(i\) to the nearest interface \(i-1\) and \(i+1\). Whenever the snap does not work, it is probably caused by the fact that the interface to be snapped at, is not directly above- of beneath the interface considered.


pictures/h5/image739.png View
Click this button to show the name of the cross-section and the name of the interfaces that crosses the current cross-section as shown on the Cross-Section CHILD window. It gives the name of the cross-section (e.g. LINE_1 and LINE_2) that intersects the current cross-section and the interface number (e.g. Interface: 1, Interface: 2, ..., Interface: 5).

Example of a cross-section displaying crossing interfaces

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The iMOD Cross-Section CHILD window shows all the interfaces. The iMOD Cross-Section CHILD window provides the opportunity to edit the interfaces manually. When the cursor of the mouse is moved in the neighbourhood of an interface, it changes in a red arrow and the left mouse button can be clicked to drag the line to another position. When the cursor becomes a black arrow the existing node of the line can be modified. This editing mode is similar to modifying polygons, see Section 4.3. In the interpolation of the interfaces, the points will be included, the more points are defined, the more accurate the resulting interface matches the cross-section. Note Be aware that there is no possibility to undo move actions.

Example of adding a new node to the cross-section

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If the cursor shows a red-arrow, it is possible to click the right-mouse button to display the following floating menu:

Example of the floating menu to edit an interface

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Delete Current Node
Select this option to delete the current selected node

Change Current Line Colour …
Click this option to change the current colour of the selected interface.

Change Current Line Thickness
Select this option to select a line thickness. Choose between Thin(1), Normal(2) and Thick(3).

Example of the different line thicknesses for interfaces

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Activate Selected Lines
Select this option to activate all lines that belong to the selected nodes.

Deactivate Selected Lines
Select this option to deactivate all lines that belong to the selected nodes.

Draw Lines as Splines
Select this option to display all interfaces as splines.

Example of spline interfaces.

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Whenever the right-mouse button is clicked on the graphical canvas of the Cross-Section window, the following floating menu appears.

Example of the floating menu

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Change Label[name]
Select this option to specify a label name for the selected interface. This option is only valid whenever the mouse is selecting one of the interfaces, mouse symbol need to turn into a black or red arrow.

Example of the setlabel name window

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Add Knickpoint
Select this option to include a knickpoint on the selected cross-section. The knickpoint will be added to the cross-sectional line and displayed as a vertical dashed line. The actual position in 2-D can be modified on the Cross-Section window. It is possible to assign a labelname to the knickpoint, which can be modified via the Cross-Section Properties window on the Coordinates tab.

Example of the window to add a label to a knickpoint

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Select Nodes
Select this option to modify nodes which are selected by drawing a polygon. After drawing this polygon the following window appears.

Example of the window to modify the selected nodes.

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Activate Selected Lines
Select this option to activate all lines that belong to the selected nodes

Deactivate Selected Lines
Select this option to deactivate all lines that belong to the selected nodes

Delete Selected Nodes on Selected Lines
Select this option to remove all selected nodes for the selected lines in the list menu on the right (in the example these are the interfaces 1,2,3,4, and 5).

Merge Selected Interface(s) on the line of the selected Nodes
Select this option to merge (snap) all selected nodes from the selected interfaces (in the example these are the interfaces 1,2,3,4, and 5) on the selected interface on the rightmost list (in the example this is interface 2).

Split Selected Nodes on Selected Lines, use offset of (meter):
Select this option to split (un-snap) all selected nodes on the selected interfaces (in the example these are the interfaces 1,2,3,4, and 5) and set them on a internal distance of 1.0 meter.

Apply
Select this option to perform the selected action and closes the Adjust Selected Nodes window. There is no undo option build in.

Help …
Click this option to start the Help functionality.

Close …
Click this option to close the Adjust Selected Nodes window without any modification.

Activate Current Interface
Select this option to activate the selected interface.

Deactivate Current Interface
Select this option to activate the selected interface. An interface that is deactivated, it (i.e. all nodes on the interface) will not be used in the interpolation. An interface that is deactivated will appear as a dashed line.

Example of a deactivated interface.

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Draw Interfaces as Splines
Select this option to display all interfaces as splines.

Open Background Image …
Click this option to select a BMP, PCX, JPG, PNG-file to be shown as background map, it has the same functionality as described at Add a bitmap as background for the Cross-Section Tool, see Section 7.1. The important difference is that the image is “attached” to the current cross-section and will therefore be part of the SPF file. Its definition (position and file name) is saved at the bottom of the SPF file, e.g.

-550.6,13.7,3721.9,-33.5,“D:\IMOD-MODELS\CROSS-SECTION_RESIZED.PNG”


Example of a bitmap combined with the cross-section.

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Remove Background Image …
Click this option to remove the bitmap as background map, the image will be removed from memory but not from the disk. It will also be removed from the SPF file in the case the solid is saved.

Hide Background Image
Click this option to hide the bitmap as background map temporarily. After this option has been selected the menu string changes to Unlock Background Image which can be selected again to undo the locking.

Lock Background Image
Click this option to prevent the bitmap for modifications, such as size and position. The mouse will not respond to the appearance of the bitmap. After this option has been selected the menu string changes to Unhide Background Image which can be selected again to show the bitmap again.

Flip Horizontally, Flip Vertically
Click this option to flip the bitmap horizontally or vertically. Note If agreed, the flipped image will overwrite the original file.

Question window to overwrite the original bitmap file.

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3D Tool
Click this button to start the 3D Tool (see Section 7.3) in combination with the selected Solid. The Fence Diagrams tab contains all existing cross-sections which can be displayed all together or separately in different configurations, more detailed information is given in the section Section 7.3.7.

Example of the 3-D representation of the cross-sections.

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Example of the 3-D representation of the cross-sections.

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Compute
Click this button to compute 2-D elevation of all interfaces in the selected solid based on the cross-sections described in the SPF files (see section Section 9.22), individual boreholes, fault lines and/or masks/polygons, all mentioned and configured in the SOL file. iMOD facilitates the Kriging interpolation method to convert the data into a 3-D representation of the subsoil. Basically, iMOD performs a Kriging interpolation using only the knick points in the interfaces, yielding a smooth interpolation.

Example of the Compute Interfaces window.

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Calc
Check this option to select the interfaces to be computed, if not selected, those will remain unchanged, unless the option Check is activated. In that case they might be adjusted due to the consistency checking performed after the simulation.

Check
Check this option to perform a consistency check upon the interfaces. iMOD uses the rule that interface \(i\) must be \(<=\) interface \(i-1\), if not the interface \(i\) becomes at least equal to the value of interface \(i-1\). It is not necessary to actually calculate the interfaces (Calcis checked) to be part of the consistency check.

Resolution
Enter a resolution for the individual interfaces saved as individual IDF files. It has the advantage to start at a coarse scale (e.g. 100 meter) to have a quick results of the interpolation and whenever the SOLID improves, the final interpolation can be carried out on a finer scale. Bear in mind, that the resolution need to be at least as fine as the detail of the cross-sections in order to capture it. If multiply knickpoint are within a single cell, the average value will be applied. At the end, the specified cell size in the model can be modified by iMOD and/or iMODFLOW and causes the interfaces to be up- or downscaled automatically.

IDF
List of the used and written IDF file names for the interfaces. The SOLID tool always uses those IDF files at {IMOD_USER}\SOLIDS\{SOLIDNAME}, results might be written in a different version folder, see Output settings.

Compute SOLID for Extent (x1,y1,x2,y2)
Check this option and enter the extent for which the SOLID need to be computed. In this manner the existing output interface files (e.g. INT_L1.IDF, INT_L2.IDF, etc.) can be enlarged or reduced.

Define Kriging Settings for Interface (0=all)
Select the appropriate interface for which Kriging settings need to be adjusted. It is possible to use different settings per interface. Whenever 0 is given in the integer field to the left, the Kriging settings apply for all interfaces. Alternatively, whenever a value of e.g. 4 is entered, the specific Kriging settings apply for interface 4 solely.

Kriging Proporties ...
Click this button to show the settings of the Kriging interpolation, see Section 4.1 for more detailed information. Bear in mind, that the most important parameter for Kriging is the type of Kriging (Ordinary and Simple) and the range over which the semivariogram (correlation) extends. Changing that parameter does probably have the largest impact on the results of the interpolation.

Get Semivariogram ...
Click this button to compute the semivariogram for the selected layers at Calc in the table. For each of the interfaces the semivariogram will be displayed in a graph. By clicking the Cancel button the next interface will be computed. Before the semivariogram will be computed, it is necessary to confirm this action since, it might can take some while to compute.

Example of a computed Semivariogram

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Export Interpolation Points to
Select the option *.IPF or *.GEO (Geometry File for the M-Series of Deltares) to export the knickpoints on each interface to an IPF or GEO file. A separate IPF or GEO file will be created and stored in {IMOD_USER}\SOLIDS\{SOLIDNAME}\{VERSION}\EXPORT. In this manner those IPF files can be manipulated such that they can be used in another software program. Use the Export … option to start the export.

Example of an exported IPF file

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Overwrite Initial Elevations as …
Overwrite the original interfaces in the folder {IMOD_USER}\SOLIDS\{SOLIDNAME}. This is the default option.

Save in a Separate Folder …
Save the result of the interpolation as a new version with the specified version number e.g. {IMOD_USER}\SOLIDS\{SOLIDNAME}\{VERSION}. The number denotes the actual {VERSION} folder.

Compute …
Start the interpolation for each interface. iMOD needs a confirmation in order to start the interpolation.

Example of the Question window

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iMOD generates a consistent 3-D image of the interfaces as defined by the cross-sections and other data if applicable.

Example of the yielding 3-D Interpolation

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iMOD also generates the standard deviation due to the interpolation. Those IDF files are called INT_L1_STDEV.IDF, INT_L2_STDEV.IDF and so on. Those images can be used for different realisation of the subsoil in a later stage as they represent the additional uncertainty to the interpolated interfaces.

Example of the yielding uncertainty for an individual interface

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Export
Start the export of the knickpoints for each interface. iMOD needs a confirmation in order to start the export.

Example of the Question window

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Help
Click this button to start the Help functionality

Close
Click this button to close the Compute Interfaces window and return to the Solid Tool window.


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Delete
Click this button to delete the selected solid, iMOD will remove the folder {USER}\{SOLIDS} and its content.

Plot SPF name

Select this option to display the name of each SPF in the 2-D plot.

Example of plotting each SPF with their associated names

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2.00

Enter the text size at which the SPF names are plotted.

Feed Selected SOL-file to the iMOD Manager

Click this item to let iMOD read automatically the solid properties and to add the solid IDF-files to the iMOD Manager when clicking the name of the solid in the list. iMOD creates an MDF files for all INT_L{i}.IDF files. Make sure the appropriate solid has been selected priorly from the list.

Help ...

Click this button to start the Help functionality.

Close

Click this button to close the Solid Tool window.

Solid Tool window, Polygons tab:

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The interpolation of the interfaces of the solid may be executed within the limits of one or more defined polygons solely. In this manner it is possible to adjust any geological model locally. Each polygon will act similar for to modellayers. If different areas need to be applied for different model layers, the use of the Masks window (see AquitardsMasks tab on the Solid Tool is more appropriate. The polygons are defined in the Solid Tool window, Polygons tab and the functions of those buttons are described in detail in section Section 4.2.

Example of a polygon (SHAPE1) that defines the area for which interfaces of the solid will be adjusted by the two drawn cross-sections.

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The defined polygon is saved to the solid when tabbing towards to the Solids tab of the Solid Tool window. The defined polygon is not saved to the solid when clicking the Close button on the Solid Tool window.

Solid Tool window, AquitardsMasks tab:

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The extent of the aquitards located between the bottom and top interfaces of subsequent layers can be defined using masks. In this manner the extent can be formed by values in the mask files. Those mask files are IDF files that can be created using the New button (see below) and/or created differently as long as the dimensions of the Mask-IDF is identical to the IDF files listed in the SOL-file. Eventually, any Mask IDF file will be saved in the selected SOL file whenever the tab Solids on the Solid Tool window is selected. The values in the Mask IDF behave as follows:

\(-2\)

iMOD applies a value of \(-2\) internally to fixate locations that are effected by cross-sections.

\(-1\)

Use this value to specify areas that do not need to be computed. iMOD will use the original values instead.

\(0\)

Use this value to specify areas that are excluded.

\(1\)

Use this value to specify areas that need to be compute.

\(2\)

Use this value to specify areas that need to be equal to the values of the upper layer. It will act as if its value is \(-1\) but uses the results from the upper layer as fixated value. The value 2 is recommended to extent aquitards, specify a value of \(+2\) outside the extent of an existing aquitard or equivalent in order to define the boundaries of these aquitard.


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New
Click this button to create new masks for all aquitards. iMOD will compute a Mask Value of \(1\) for the bottom elevation of modellayer \(i\) where there is a positive difference with the underlying top of modellayer \(i+1\). Outside those area, the Mask Value is \(1\) and for the top of the underlying modellayer \(2\). An information window appears specifying the created masks.

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Open Map
Click this button to open an IDF-file to be used as mask file.


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Properties
Click this button to open the properties of the mask.


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Delete
Click this button to remove the mask file from the list.

Solid Tool window, Faults tab:

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The interpolation can be obstructed by the shape of faults, or breaklines. Those need to be entered as GEN-files (see section Section 9.11).

Interface

Enter the number of the interface for which the faults or breaklines need to be applied.

GEN-file

Enter the name of the GEN file which contains the breaklines. More than one breakline may be present in each GEN file.