Automated Draw Cross Sections Command (GeoSTORM)

In GeoSTORM software, the Automated Draw Cross Sections command allows the user to automatically generate cross sections along a routing reach.

Follow the steps below to use the Automated Draw Cross Sections command:

1. From the Input ribbon menu, click on the Cross Sections dropdown menu and select the Automated Draw Cross Sections command.
   
2. The Automated Draw Cross Sections dialog box will be displayed.
   

The following sections describe how to use the Automated Draw Cross Sections command and interact with the above dialog box.

Selecting Reach Polyline

The Select Reach Polyline section is used to select the reach polyline(s) on the Map View that will be used to automatically draw cross sections.

To select reach polyline(s), click the [Pick] button, and the dialog box will temporarily disappear. A prompt will be displayed on the status bar of the Map View instructing the user to select the reach polyline(s).

After selecting the reach polylines, press the [Enter] key or right-click and select Done from the displayed context menu. The Automated Draw Cross Sections dialog box will be redisplayed, and the total number of selected reach polyline(s) will be shown in the Reach Polyline read-only field.

Note that if reach polylines are preselected on the Map View, the same number of selected polylines will be displayed in the Reach Polyline read-only field.

Automated Draw Specifications

General Settings

The General Settings panel is used to define the general settings for the cross sections to be created.

The following subsections are available in this panel:

Cross Section River Stationing

This subsection is used to control the numbering of the cross section river reach stations. The cross section river reach stations need to be unique per river reach and their value must increase as they move up the river reach.

The following option is provided in this sub-section:

• Numbering Direction: This dropdown combo box defines the direction in which the cross section IDs should increase. The following options are provided:
  1. Downstream
  2. Upstream

Use Reach Distance

This subpanel is used to number the cross sections by using the river chainage along the river reach. The following options are provided:

• Distance Units: This dropdown combo box defines the unit of the reach length. The available options are:
  1. Feet
  2. Miles
• Decimal Precision: This optional checkbox entry defines the decimal precision to be used in determining the cross section IDs. By default, this checkbox is disabled (i.e., grayed out). If enabled, then the user can enter any value ranging from 0 to 6.

Cross Section Placement

This subsection is used to define the placement of cross sections along the selected river reach polylines.

The following options are available in this section:

• Approximate (max) cross section spacing: This entry field allows the user to define the maximum distance between cross sections when placing them. The software will attempt to uniformly space the cross sections along each reach, up to this approximate (max) spacing. This prevents the last cross sections created along a reach from being spaced too close together. By default, the software uses a value of 500 feet (when working in US units) or 150 meters (when working in metric SI units). Clicking on the […] button allows the user to measure the approximate (max) cross section spacing from the Map View.
• Cross section width: This entry field allows the user to define the cross section width to be used when extracting cross section geometry from the terrain data. However, the defined cross section width is a starting point. Additional criteria are provided to control how much data is to be extracted when the user extracts the ground geometry from the terrain. By default, the software uses a value of 500 feet (when working in US units) or 150 meters (when working in metric SI units). Clicking on the […] button allows the user to measure the cross section width from the Map View.
• Offset from downstream reach end: This entry field is used to define the distance from a downstream reach end where cross sections should be located. This prevents a cross section from being placed directly at a river reach. By default, the software uses a value of 500 feet (when working in US units) or 150 meters (when working in metric SI units). Clicking on the […] button allows the user to measure the offset from the river reach end from the Map View.

  Note that if the Downstream option is selected in the Numbering direction dropdown combo box, then the Offset from downstream reach end entry field will be changed to Offset from upstream reach end.
  

Extraction Data

This panel is used to define the data extraction specifications based on the options selected for the cross sections.

The following subsections are available in this panel:

Extract Elevation Data

This subsection defines the source for terrain elevation used to extract cross section geometry. Depending upon the terrain elevation source selected, different options are provided to specify additional elevation data information.

The following options are available in the Terrain elevation source dropdown combo box:

• CAD Drawing
• Elevation Grid
• GIS Contours
• LandXML Data
• Terrain Surface
• TIN Surface

CAD Drawing

If the user selects CAD Drawing as the terrain elevation source, the content of the Extract Elevation Data section changes, as shown below.

The following options are displayed when CAD Drawing is selected as the terrain elevation source:

• CAD drawing layer: This dropdown combo box allows the user to select the CAD drawing layer available in the project.
• Drawing layers: Clicking the [Define] button adjacent to the Drawing layers entry displays the CAD Drawing Layers dialog box allowing the user to define the properties of the drawing layers, as shown below.
  

Elevation Grid

If the user selects Elevation Grid as the terrain elevation source, the content of the Extract Elevation Data section changes, as shown below.

The following option is displayed when the Elevation Grid is selected as the terrain elevation source:

• Elevation grid layer: This dropdown combo box allows the user to select the elevation grid layer available in the project.

GIS Contours

If the user selects GIS Contours as the terrain elevation source, the content of the Extract Elevation Data section changes, as shown below.

The following options are displayed when GIS Contours is selected as the terrain elevation source:

• GIS polyline layer: This dropdown combo box allows the user to select the GIS polyline layer type.
• Elevation attribute: This dropdown combo box allows the user to select the elevation attribute type.

LandXML Data

If the user selects LandXML Data as the terrain elevation source, the content of the Extract Elevation Data section changes, as shown below.

The following options are displayed when the LandXML Data is selected as the terrain elevation source:

• TIN surface layer: This dropdown combo box allows the user to select the TIN surface layer type.
• TIN surface: This dropdown combo box allows the user to select the TIN surface type.

Terrain Surface

If the user selects Terrain Surface as the terrain elevation source, the content of the Extract Elevation Data section changes, as shown below.

The following option is displayed when the Terrain Surface is selected as the terrain elevation source:

• Terrain surface layer: This dropdown combo box allows the user to select the terrain surface layer type.

TIN Surface

If the user selects TIN Surface as the terrain elevation source, the content of the Extract Elevation Data section changes, as shown below.

The following options are displayed when the TIN Surface is selected as the terrain elevation source:

• TIN surface layer: This dropdown combo box allows the user to select the TIN surface layer type.
• TIN surface: This dropdown combo box allows the user to select the TIN surface type.

Note: Unchecking the Extract Elevation Data checkbox option disables (i.e., grays out) all the options under the Extraction Data panel.

Cross Section Geometry Extraction Control

The user needs to check the Cross Section Geometry Extraction Control checkbox to enable the content of this subsection. This subsection allows the user to control the amount of cross section geometry to extract for the drawn/assigned cross section polyline. This ensures that an adequately deep enough cross section is created on both sides of the river reach. The software will try to compute the cross-section geometry data up to the specified depth and within the maximum width defined in this subsection.

If the selected polyline does not extend outward far enough to get the cross section depth specified, the software will automatically extend the constructed cross section further outward. Similarly, if the selected polyline extends too far outward for the depth specified, the software will automatically trim the constructed cross section.

Alignment Settings

This panel is primarily used to perform automated cross section creation along sinuous (meandering) river reaches and is not used for other conditions. By default, the content of this panel is disabled (i.e., grayed out). To enable, check the Generalize Cross Section Alignment checkbox option.

Generalize Cross Section Alignment

This subsection allows the user to control the river reach and cross section alignment smoothing and generalization. If this checkbox option is checked, the following options will be enabled:

• River valley alignment polyline control pt spacing
  This entry field allows the user to enter the distance for smoothing river reach. Clicking the […] button allows the user to measure the distance between spline control points from the Map View for smoothing river reach.

• Draw generalized river valley alignment polyline
  This checkbox option is used to draw the computed generalized river reach alignment polyline.

• Orthogonal channel alignment between banks
  This checkbox option is used to make the cross section orthogonal between the channel bank stations and generalized in the floodplain. Note that the bank station definition is required to perform an orthogonal channel alignment between bank stations.

Roughness

This panel allows the user to adjust the Manning’s roughness values for the left overbank, channel, and right overbank areas during the construction of cross sections.

During the construction of cross sections, the software will automatically assign a default Manning’s roughness for the left overbank, channel, and right overbank areas. Clicking the […] lookup buttons adjacent to these Manning’s roughness entry fields displays the Manning’s Roughness lookup dialog box that allows the user to select Manning’s roughness coefficients, as shown below.

Generating Cross Section

When all the options have been properly defined in the Automated Draw Cross Sections dialog box, click the [Generate] button. The software will automatically generate the cross sections along a river reach.