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Table Of Contents
Chapter 5 Working with Hydrology Commands
568
Specifying the Rainfall Intensity
NOTE
If you have already defined Rainfall Frequencies, click Load and pick the file
that contains this information.
To define rainfall intensity-duration information
1 From the Rational Method dialog box, click IDF to display the Intensity
Frequency Factor Editor dialog box.
2 Click Insert Frequency to display the Add Frequency Curve dialog box.
3 In the Frequency box, type a frequency for which you will define various
rainfall durations and corresponding intensities. For example, enter 10 to define
the rainfall intensity duration information for a 10-year storm.
NOTE
Just type the number; do not type "years" after typing the number.
4 Click OK to return to the Intensity Frequency Factor Editor.
5 Repeat steps 1 through 3 until you have added all the rainfall frequencies you
want to define.
6 From the Intensity Frequency Factor Editor dialog box, pick a rainfall frequency
from the Rainfall Frequency list.
7 In a Duration box, type the duration value for the rainfall frequency you
selected. In the Duration column, pick a text box and enter a value (such as 0.5
for 30 minutes). You can define as many durations for the selected Rainfall
Frequency as you need.