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Define Properties


At this step, you can assign, edit, and copy the flow (and transport) properties for the model. You can also adjust the view/style settings of properties or export the properties.


You can assign properties while viewing either by Layer, Row, or Column; however you cannot edit properties when the 3D subview is active.

Under the Toolbox, use the combo box to select from the available property groups:

Flow Parameters

oConductivity: includes horizontal conductivity in the X direction (Kx), in the Y-direction (Ky), and vertical conductivity (Kz)

oStorage: includes Specific Storage (Ss), Specific Yield (Sy), Total Porosity (Tp), and Effective Porosity (Ep)

oInitial Heads

oVadose Zone: only available/required if using MODFLOW-SURFACT or MODFLOW-2005/MODFLOW-NWT with the UZF package


When transport is included with your model, the following additional property groups may be included:

Transport Parameters

oInitial Concentration Group - one node for each Species

oSpecies Parameters Group(s) - one or more node for each Species

oModel Parameters Group(s)

oDispersion: includes longitudinal dispersion (used by all transport engines) and other terms in the dispersion tensor (ALV, ATH1, ATH2, and ATV) that are only used for MOFLOW-6 GWT models


Please Note: the number of Species Parameters and Model Parameters (if any) will depend on what Sorption and Reaction options you have defined in the Define Modeling Objectives step. Please also refer to the Theory section.


For each parameter group, you can choose to render by Zones or by a selected attribute. Based on your selection, the color rendering in the views will change.

The display tools will allow you to switch from discrete cells rendering to color shading/contours (note, this is available only when you do attribute rendering, and not when you are rendering by ZoneID)

Show/hide grid lines

Show as cells

Show as Surface


At the bottom of the display, you will see in the status bar the position of your mouse cursor in the current view (XY) grid position (Layer, Row, Column), and the Zone ID or attribute value for the selected cell.

For more details on the required flow and transport parameters for each category, please see section: Background on Flow and Transport Properties



Property zone values can be assigned directly to selected numerical cells using the Assign options from the toolbox.

Single: Select one or more cells with the left mouse button; a small red point will appear over the selected cell

Polyline: Draw one or more polylines to select the desired cells

Polygon: Draw one or more polygons to select the desired cells

Entire Layer/Row/Column: Selects the currently selected layer/row/column (all active cells)

Using Data Object: Use data object (points, polylines, or polygons) to select the desired cells


When you use either the Assign/Polygon or Assign/Entire Layer option, the property zone will be assigned to the numerical grid and a corresponding conceptual property zone representation will be created; this is useful when you re-run the Conceptual to Numerical Conversion option for the current (or new) numerical grid.

However, when you use the Assign/Single or Assign/Polyline options, no conceptual property zone is created; please be aware of this limitation should you choose to create a new numerical model from the conceptual model; the property values in this new model run may need to be adjusted.

After you have done the desired cell selections, right click with the mouse to close the shape and select "Finish".

The New Property Zone window will appear as shown below.



In the top left, select which zone the selected cells should be assigned to (from the combo box).  If you choose an existing zone, the parameter values cannot be adjusted from within this GUI (instead, select the Edit option described above, to adjust parameter values for existing zones.)

Or, click the [New] button to create a new property zone. After doing this, a new zone number will be incremented. Next, select in which layers the new property zone should be generated, by default, your current layer will be selected, however you can include other layers or select all layers.

Lastly, define the "Zone Attributes" for this new property zone in the main grid.  There are several "Methods" for defining the attributes, and these include Constant Value and Use Surface (Use 3DGridded Data and Use Shape Data are not applicable for this scenario).


Constant Value

The Constant Value method is selected by default for each parameter in the data input grid and allows you to specify a spatially constant value for the parameter. Replace the default value with a new value.


Use Surface

The Use Surface method allows you use an existing surface data object to define spatially-variable attribute values. This is ideal if you have a  Surfer .GRD or ESRI ASCII GRD file containing parameter values.  Follow the steps below:

Select "Surface" as the method from the combo box. You should then see the  button become beside the "Value" column

From the Data Explorer, select the desired surface data object

Click the  button to insert this data object into the Object field.


Once you are finished, click OK and the new property zone will be created.  (note, when you view the Database values for this new property zone, it will show "Distributed Values" since it contains a range of values for this zone, not just a single value).


Use 3D Gridded Data

You may want to define initial concentrations from a .UCN file from a previous transport run. In order to use this option, you must need to import the .UCN file to the project, as a "3D Gridded Data" set.  Follow these steps in the section "Import 3D Gridded Data". Once the file is imported, you select this object when defining the properties.

Use assign polygon or entire layer, to select the desired group of cells

Click the [New] button to create a new zone.

Select "Use 3D Gridded Data" as the method from the combo box.

You should then see the  button become activated beside the "Value" column

From the Data Explorer, select the desired 3D Gridded Data (which contains the imported .UCN file)

Click the  button to insert this data object into the Object field.

By default, Concentration should be selected in the "Mapping" column (you may need to re-select this from the combo box).

Once you are finished, click OK and the new property zone will be created.

You can view the Initial Concentration rendering for the full 3D grid, by changing the rendering type from "Zone" to "Initial Concentration"


Please Note: when you view the Database values for this new property zone, it will show "Distributed Values" since it contains a range of values for this zone, not just a single value)



Select the Edit button to edit Property zone values after they have been assigned and the Edit property dialog is launched. Here you can select the zone and then you will have the ability to edit any of the cells that are part of the zone.


The following buttons are available to assist with your edits:

Expression Builder

Assign to current cell

Assign to column

Apply to selected cells


The Expression Builder, which can be accessed by clicking the button, helps you to construct expressions that can include variables and mathematical functions to update property values.

Also available is the Script tab. If preferred, you can make your edits by using the Script option. On this tab you will find the script for any edits you make on the Edit Cells tab allowing you to learn the script language. You can then use the script to "replay" the same edits again.



Property zone values can be copied from the current view to selected numerical cells using the Copy options from the toolbox:

Entire Layer/Row/Column: copy the properties from the active layer, row, or column view to selected layer(s), row(s), or column(s) based on the active view

Copy zones to another property: copies the property zones for the entire model domain from the current property zone to another selected property type


Copy Entire Layer/Row/Column

Select the Copy button and the Entire Layer/Row/Column option to copy property values from the current Layer, Row, or Column based on the active view (i.e. the active view is highlighted in blue) to other layer(s), row(s), or column(s).  Note that you can click in a view to make it the active view. Also note that the currently active layer, row, or column will be filtered from the list.



Copy zones to another property

Select the Copy button and the copy zones to another property option to copy the entire set of property zones from the current property type to a different property type.  Note that only the zones will be updated, you will need to update the other attributes accordingly.



Adjusting Style Settings

Each group of flow properties exists as a separate item in the model tree, as shown below.

Right click on each node, and select Settings. This will allow you to modify the appearance of each group of flow properties.


In addition, each property group can be added to a stand-alone 3D view; to do this, right click and select 3D-Viewer.

The 2D Colors and Contour line settings can be adjusted. For more details, see Color and Contour settings


Export Properties

Any of the model properties can be exported to a shapefile; see Export for more details.



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