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Table Of Contents
Time of Concentration and Time of Travel
561
TIP
To display the shallow flow data in a text editor, click Output. From here,
you can print the data to a file or printer.
5 Click OK.
Specifying the Channel Flow
The open channel flow is water flowing in constructed channels. Open
channels are assumed to begin where surveyed cross section information has
been obtained, where channels are visible on aerial photographs, or where
streams display on USGS quad sheets.
Mannings equation or water surface profile information can be used to estimate
average flow velocity. Average flow velocity is usually determined for bank-full
elevation.
To calculate channel flow, you need the following information: geometry of the
channel, Mannings n for the channel, and average slope. The Channel Flow
Time Calculator dialog box is available from the following dialog boxes:
n
Time of Concentration Calculator
n
Time of Travel Calculator
To specify the channel flow
1 In the Channel Flow Time Calculator dialog box, type a description for the
channel flow segment in the Description box.
2 In the Cross Section Area box, type the channel cross sectional area for bank-full
conditions (when the channel is filled to the bank).
3 In the Wetted Perimeter box, type the wetted perimeter of the channel. In cross
section view, a channel has an approximate U-shape. The wetted perimeter is
the length of this U.