2.0

Table Of Contents
Chapter 5 Working with Hydrology Commands
606
Selecting the Current Surface to Use for HEC2 Output
Use the Select Surface command to set the current surface for the drawing. The
current surface is used to establish rim elevations and inverts for the pipe run
nodes and to specify a surface for extracting section data for HEC output.
NOTE
The surface stays current for the drawing session only. You must set a
current surface each time you open the drawing.
To select the current surface
1 From the Hydrology menu, choose HEC2 Output ä Select Surface to display the
Select Surface dialog box.
2 Select the surface you want to use, and then click OK. The surface you selected
is now set as the current surface.
Drawing a 2D Polyline to Use as a Cross Section
Sampling Line
To create a single cross section, you must first draw a section line with the Draw
Sections command. Then you can select this 2D polyline when you are using
the Plot Single Section command.
To draw a 2D polyline for use as a cross section sampling line
1 From the Hydrology menu, choose HEC2 Output ä Draw Sections.
The following prompt is displayed:
Specify start point:
2 Select a starting point for the polyline by picking it from your drawing.
The following prompt is displayed:
Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width/]:
3 Select at least one more point to create a polyline.
You can draw an arc, for example, by typing Arc at the command prompt,
pressing ENTER, and picking the arcs endpoint. To undo the last point you
picked, type Undo at the command prompt and press ENTER.
4 Press ENTER to end the polyline.
Plotting Single Sections
You can plot cross sections one at a time by using the Plot Single Section
command. You can either define the cross section sampling lines by selecting
two points on a surface, or by selecting an existing line, arc, or polyline.
NOTE
You can use the Draw Section command to draw a cross section line.