Automated Draw River Reaches Command

The Automated Draw River Reaches command allows the user to automatically draw river reaches on the Map View for the user selected location(s).

Follow the steps below to use the Automated Draw River Reaches command:

From the Input ribbon menu, click on the River Reaches dropdown menu and then select the Automated Draw River Reaches command.
The Automated Draw River Reaches dialog box will be displayed.

The following sections describe the Automated Draw River Reaches command and how to interact with the above dialog box.

Selecting River Reach Starting Point

The Select River Reach Starting Point section is used to select a starting point on the Map View for drawing a river reach.

To select a starting point, follow the steps below:

Click the [Pick] button and the dialog box will temporarily disappear.
The status bar (shown under the Map View) will prompt the user to select a starting point on the Map View for drawing the river reach.
Once the river reach starting point is selected, the Automated Draw River Reaches dialog box will be redisplayed, and the Select point read-only field will be changed from Not Selected to Selected.

River Reach Draw Direction

This section is used to define the direction of the river reach polyline that will be drawn based upon the selected starting point.
River Reach Draw Direction

This section contains the following options:

Downstream flow direction
This radio button option is used to select the flow direction of the river reach polyline downstream from the starting point. By default, this option is selected.
Upstream flow direction
This radio button option is used to select the flow direction of the river reach polyline upstream from the starting point.

River Reach Specifications

This section is used to specify the River name and the corresponding Reach name for each drawn river reach. The user can manually enter the river and reach names. The [New] button can be used to create a new river.
River Reach Specifications

General Options

This section is used to define the following options for drawing a river reach.
General Options

Terrain surface
The dropdown combo box lists the terrain surfaces associated with the project which are used to define the reach polyline. By default, the current scenario’s terrain surface is selected. If there is no terrain surface defined for the selected scenario, then this entry is blank.
River reach maximum length
This optional checkbox entry is used to define the maximum length of the drawn river reach polyline. If this checkbox entry is left blank/unchecked, the river reach polyline will be extended to the limits of the underlying flow direction grid.

Alternatively, click the [Pick] button to draw a river reach polyline representing the maximum river reach length. On clicking the [Pick] button, the dialog box will temporarily disappear. A prompt will be displayed on the status bar instructing the user to draw an approximate river reach polyline on the Map View.

When drawing a river reach polyline by holding down the [Shift] key, the drawing is done along an ortho line. Similarly, if the user holds down the [Ctrl] key while drawing, the drawing is done along a curvilinear line. In addition, the status bar shows the accumulated length while drawing the river reach polyline. Once finished, press the [Enter] key or right-click and select Done from the displayed context menu. The drawn polyline will be removed, and the Automated Draw River Reaches dialog box will be redisplayed with the measured distance, as shown below.

Computing River Reach

After defining all the required options, click the [Compute] button to compute the flow direction grid for the selected terrain surface.

While the computation is running, the [Compute] button will change to [Cancel] button, which allows the user to abort the command if needed. In addition, a progress bar at the bottom will show the progress of the computation along with status messages.

After computing the flow direction grid, the software will automatically generate a river reach on the Map View.