6.0 Nodes and Elements
======================
6.1 Selecting Elements
----------------------
The **MINEDW** software provides tools for selecting nodes and
elements to perform the following tasks:
1. Assign and edit properties that are defined on elements, such as
hydraulic conductivity and storage zones, recharge zones, and
evaporation zones;
2. Assign and edit the boundary conditions related to nodes, such as
constant heads, pumping wells, and variable-flux boundary conditions;
3. Move nodes within the finite-element mesh;
4. Add pinch-outs for increased vertical model discretization; and
5. Refine and extend the mesh.
The tool buttons that are used to select nodes and elements are listed
in Table 6.1, below.
Table 6.1 The Nodes and Elements Tool Buttons
.. raw:: html
|
Select Elements or Nodes |
|
Select with Polygon |
|
Select with Overlay |
|
Move Nodes |
|
Search Node/Element |
|
View Mode |
When modifying the element- or node-related properties, it is important
that the plot item being modified (node or element) is the first active
plot item in the “\ *Plot Items*\ ” pane. When selecting elements and
assigning new hydrogeologic zones, for example, the “\ *Element*\ ” plot
item should be the first active plot item in the “\ *Plot Items*\ ”
pane. Conversely, when selecting nodes and assigning a ground-surface
elevation, the “\ *Node*\ ” plot item should be the first active plot
item in the “\ *Plot Items*\ ” pane. To select elements, use the
“\ *Select*\ ” tool when element-related plots are displayed in the View
Pane. Element-related plots include “\ *2-D Plane”* and “\ *3D Element”*
plots, which can be found in the “\ *Control Panel*\ ” under the
“\ *List*\ ” menu. In the “\ *Control Panel*\ ” Pane, under either the
2-D or 3-D plot attributes, the user can specify the elemental data
(e.g., hydraulic zones using the “\ *3D Element*\ ” plot item or
evaporation and recharge using *“2-D Plane”* plot items) to view,
select, and edit.
6.1.1 Selecting Elements in 2-D
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If an element-related plot is displayed, then the elements can be
selected using the following approaches:
- Click the “\ *Select*\ ” tool and then click individual elements in
the View Pane. To deselect individual elements, right-click on the
selected element. To deselect all selected elements, press the [Esc]
key.
- Click the “\ *Select*\ ” tool and then click and drag the cursor to
select the elements in a rectangle. Right-clicking and dragging a
selection box around selected elements will deselect the elements.
- Click the “\ *Select*\ ” tool and then click the “\ *Select with
Polygon*\ ” tool, shown in Table 6.1. Use the “\ *Select with
Polygon*\ ” tool to select multiple elements in a desired area in the
model domain. To close the polygon, press the [Enter] key.
- Add a point, polyline, or polygon file to the View Pane using the
*“BLN,” “ESRI Shape File*,” or “\ *Point Data*\ ” plot items. The
file that will be used as an overlay must be added to the View Pane
(see Section 3.4.1.8) before the “\ *Select with Overlay*\ ” tool is
clicked. If multiple overlays are added to the View Pane, only the
topmost listed in the *“Plot Items”* pane will be used to select. To
use the overlay below the topmost overlay, the latter should be
deactivated. Click the “\ *Select*\ ” tool and then click the
“\ *Select with Overlay*\ ” tool. When the “\ *Select with
Overlay*\ ” tool is activated, the dialog box shown in Figure 6.1
appears. To deselect a selected element, right-click on that element
or right-click and drag a rectangle around multiple selected
elements. Press the [ESC] key to deselect all selected elements.
.. figure:: media/figure_6_1_manual.png
:width: 2.29167in
:height: 1.47902in
:align: center
Figure 6.1 The “\ *Choose Method of Selection*\ ” dialog box
To exit the select mode, click the “\ *View Mode*\ ” tool. To deselect
all elements before editing, press the [ESC] key.
As previously described, there are three options when selecting elements
with an overlay file. If the “\ *Point*\ ” option is selected, then the
closest elements for each point are selected. If the “\ *Polyline*\ ”
option is selected, then elements along the polyline are selected. If
the “\ *Polygon*\ ” option is selected, then the elements inside the
polygon are selected.
After the elements are selected, press the [Enter] key, and one of the
dialog boxes shown in Figures 6.2, 6.3, and 6.4 appears. These dialog
boxes can be used to edit the recharge zone (Figure 6.2), evaporation
zone (Figure 6.3), or geological zone (Figure 6.4) input data.
.. figure:: media/figure_6_2_manual.png
:width: 2.66667in
:height: 1.07292in
:align: center
Figure 6.2 The “\ *Select Recharge Zone*\ ” dialog box
To edit the spatial distribution of recharge zones, select elements
using a “\ *2-D Plane*\ ” plot item and change the “\ *Color By*\ ”
attribute to “\ *Recharge*.” When the “\ *Select Recharge Zone*\ ”
dialog box appears, the recharge zone for the selected elements can be
assigned using the drop-down box next to “\ *Zone*.”
.. figure:: media/figure_6_3_manual.png
:width: 2.67708in
:height: 1.07292in
:align: center
Figure 6.3 The “\ *Select Evaporation Zone*\ ” dialog box
Evaporation zones can be assigned and modified in a manner similar to
recharge zones. Change the “\ *Color By*\ ” attribute on the “\ *2-D
Plane*\ ” plot item to “\ *Evaporation*,” select the desired region as
previously described, and then press the [Enter] key; the “\ *Select
Evaporation Zone*\ ” dialog box then appears. Using the drop-down box in
the “\ *Select Evaporation Zone*\ ” dialog box, select the desired
evaporation zone to assign the zone to the selected elements. More
information on assigning recharge and evaporation is provided in Section
7.4.
Use a “\ *2D Element*\ ” or “\ *3D Element*\ ” plot item to assign
geologic properties to elements. When the desired elements are selected,
press the [Enter] key, and then the “\ *Select Geological Zone*\ ”
dialog box shown in Figure 6.4 appears.
.. figure:: media/figure_6_4_manual.png
:width: 4.72983in
:height: 1.98986in
:align: center
Figure 6.4 The “\ *Select Geological Zone*\ ” dialog box
Element properties in multiple layers can be changed by entering the
layer to extend the selected elements to, as shown in Figure 6.5. The
layer selected in the attribute panel of the “\ *Element*\ ” plot item
determines the uppermost layer that the change affects.
.. figure:: media/figure_6_5_manual.png
:width: 4.62565in
:height: 0.28129in
:align: center
Figure 6.5 The “\ *Select Geological Zone*\ ” dialog box showing the
multiple layers option
Selected element numbers can be exported by using the “\ *Export*\ ”
function shown in Figure 6.4 and specifying an output file. If elements
are exported, then the output file will contain the selected element
numbers.
6.1.2 Selecting Elements in 3-D
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Another option to select elements and assign the zone properties to the
elements is to use a .DXF file. To assign a geologic unit to an element
using a 3-D .DXF file, add a “\ *DXF”* plot item to the View Pane by
selecting “\ *List*\ ” and then “\ *File Data.*\ ” Under “\ *File
Data*,” double-click “\ *DXF*.” The “\ *Attributes*\ ” tab then appears.
Click on the “\ **+**\ ” next to “\ *File*\ ” and the *“Select DXF Data
File”* dialog box opens. Select the desired 3-D .DXF file and click
“\ *Open*.” If multiple geologic units are represented in the .DXF file,
the assignment of each geologic unit to the model elements should be
done individually. Click the “\ *Layers*\ ” button under the
“\ *Attributes*\ ” tab shown in Figure 6.6 and disable the other units
if there are multiple.
.. figure:: media/figure_6_6_manual.png
:width: 3.51091in
:height: 2.59411in
:align: center
Figure 6.6 The “\ *Attributes*\ ” dialog box
Click the symbol next to “\ *To Zone*,” as shown in Figure 6.6. The
“\ *DXF to Zone*\ ” dialog box appears. Select the desired zone to
assign to the elements in the drop-down box. For geologic units (i.e.,
objects that have a volume), select “\ *Volume*\ ”; for structures
(e.g., faults), select “\ *Face*,” as shown in Figure 6.7. For element
selection, if the “\ *Whole*\ ” option is selected, only the elements
that are completely inside of the .DXF file are selected. If the
“\ *Center*\ ” option is selected, the elements are selected if the
element centers are inside the .DXF file. Click “\ *OK*\ ” to complete
the assignment.
.. figure:: media/figure_6_7_manual.png
:width: 3.20878in
:height: 1.81275in
:align: center
Figure 6.7 The “\ *DXF to Zone*\ ” dialog box
To exit the *“Select”* mode, click the “\ *View Mode*\ ” button. To
deselect all elements before editing, press the [ESC] key.
6.2 Selecting Nodes
-------------------
The “\ *Select*\ ” tool can also be used when node-related plots are
displayed in the View Pane. Node-related plots include 2-D and 3-D
contour plots, which can be found in the “\ *Control Panel*\ ” on the
“\ *List*\ ” tab under the *“Node”* plot items group. The operations
that can be performed are described in the sections that follow. To
select the node, the node plot item should be the first active plot item
in the “\ *Plot Item*\ ” pane. Nodes can be selected using the following
methods:
- Click the “\ *Select*\ ” tool and then click on the nodes in the View
Pane. To deselect individual nodes, right-click on the selected node.
- Click the “\ *Select*\ ” tool and then click and drag the cursor to
select nodes in a rectangle. Deselect with a right click.
- Click the “\ *Select*\ ” tool and then click the “\ *Select with
Polygon*\ ” tool. Use the “\ *Select with Polygon*\ ” tool to select
multiple nodes in a desired area in the model domain. To close the
polygon, press the [Enter] key.
- Add a point, polyline, or polygon file to the View Pane using the
*“BLN,” “ESRI Shape File*,” or “\ *Point Data*\ ” plot items. Click
the “\ *Select*\ ” tool and then click the “\ *Select with
Overlay*\ ” tool. When the “\ *Select with Overlay*\ ” tool is
activated, the *“Choose Method of Selection:”* dialog box appears
(Figure 6.1). The file that will be used as an overlay must be added
to the View Pane before the “\ *Select with Overlay*\ ” tool is
clicked. If multiple overlays are added to the View Pane, only the
topmost listed in the *“Plot Items”* pane will be used to select. To
use the overlay below the topmost overlay, the latter should be
deactivated. To deselect a selected node, right-click on that node or
right-click and drag a rectangle around multiple selected nodes.
Press the [ESC] key to deselect all selected nodes.
After the nodes are selected, press the [Enter] key to open the
“\ *Assign Properties for Nodes*\ ” dialog box shown in Figure 6.8.
.. figure:: media/figure_6_8_manual.png
:width: 6.00000in
:height: 2.37708in
:align: center
Figure 6.8 The “\ *Assign Properties for Nodes*\ ” dialog box
Several operations can be performed on the selected nodes.
- Assign boundary conditions (constant head, variable flux, or pumping
wells), as shown in Figure 6.9. After selecting one of the options,
the number of layers to be assigned with the boundary conditions
should also be specified, as discussed later in this section.
.. figure:: media/figure_6_9_manual.png
:width: 4.11516in
:height: 1.07307in
:align: center
Figure 6.9 Assign boundary conditions to selected nodes
- Change the elevation of the selected nodes, as shown in Figure 6.10.
.. figure:: media/figure_6_10_manual.png
:width: 2.81364in
:height: 0.28136in
:align: center
Figure 6.10 Assign constant elevation to selected nodes
- Interpolate the elevations of the selected nodes using a data file by
clicking on the button next to “\ *Interpolated from File*,\ *”* as
shown in Figure 6.11. The format of the data file is a series of x,
y, z space delimited data.
.. figure:: media/figure_6_11_manual.png
:width: 3.89741in
:height: 0.31263in
:align: center
Figure 6.11 Assign elevation by interpolating elevation data
- After the selection of one of the boundary conditions as shown in
Figure 6.9, specify the number of layers. If nodes in more than one
layer are to be selected, then the number of layers to be modified
can be selected (Figure 6.12).
.. figure:: media/figure_6_12_manual.png
:width: 2.70871in
:height: 0.71885in
:align: center
Figure 6.12 The multiple layers specification dialog box
- Export the data. The selected node numbers can be exported to a .DAT
file by using the export button, as shown in Figure 6.13. If nodes
are exported, then the output file will contain the selected node
numbers and the corresponding node elevations.
.. figure:: media/figure_6_13_manual.png
:width: 2.56250in
:height: 0.34375in
:align: center
Figure 6.13 The options available for both nodes and elements
To exit out of the *“Select”* mode, click the “\ *View Mode*\ ” tool
after closing the *“Assign Properties for Nodes”* dialog box. To
deselect all the selected elements before editing, press the [ESC] key.
.. |figure_3_1a_manual| image:: media/figure_3_1a_manual.png
:width: 0.27094in
:height: 0.33347in
.. |figure_3_1b_manual| image:: media/figure_3_1b_manual.png
:width: 0.27094in
:height: 0.33347in
.. |figure_3_1c_manual| image:: media/figure_3_1c_manual.png
:width: 0.23968in
:height: 0.33347in
.. |figure_3_1d_manual| image:: media/figure_3_1d_manual.png
:width: 0.28136in
:height: 0.33347in
.. |figure_3_1e_manual| image:: media/figure_3_1e_manual.png
:width: 0.28136in
:height: 0.33347in
.. |figure_3_1f_manual| image:: media/figure_3_1f_manual.png
:width: 0.23125in
:height: 0.29600in
.. |figure_3_1g_manual| image:: media/figure_3_1a_manual.png
:width: 0.25312in
:height: 0.30000in
.. |figure_3_1h_manual| image:: media/figure_3_1h_manual.png
:width: 0.24193in
:height: 0.30000in
.. |figure_3_1i_manual| image:: media/figure_3_1i_manual.png
:width: 0.28136in
:height: 0.32305in
.. |figure_3_1j_manual| image:: media/figure_3_1j_manual.png
:width: 0.28136in
:height: 0.33347in
.. |figure_3_1k_manual| image:: media/figure_3_1k_manual.png
:width: 0.30000in
:height: 0.27857in
.. |figure_3_1l_manual| image:: media/figure_3_1l_manual.png
:width: 0.30000in
:height: 0.28000in
.. |figure_3_1m_manual| image:: media/figure_3_1m_manual.png
:width: 0.30000in
:height: 0.30000in
.. |figure_3_1n_manual| image:: media/figure_3_1n_manual.png
:width: 0.23968in
:height: 0.21884in
.. |figure_3_1o_manual| image:: media/figure_3_1o_manual.png
:width: 0.23968in
:height: 0.21884in
.. |figure_3_1p_manual| image:: media/figure_3_1p_manual.png
:width: 0.23968in
:height: 0.21884in