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MindTap Engineering for Garber/Hoel's Traffic and Highway Engineering, 5th Edition, [Instant Access], 1 term (6 months)
5th Edition
ISBN: 9781305581159
Author: Nicholas J. Garber; Lester A. Hoel
Publisher: Cengage Learning US
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Question
Chapter 16, Problem 7P
To determine
The rate of runoff for a storm of 100-year frequency and average velocityfor 196-acre rural drainage area.
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Students have asked these similar questions
Q2) Annual rainfall and runoff values of a catchment for a period of 10 years are given below.
Analyze the data to (a) develop a non-linear correlation equation to estimate annual runoff volume
for a given annual rainfall value, (b) Estimate r values for the equation, (c) Estimate the runoff depth
when the rainfall depth is (i) 350 mm (ii) 600 mm.
2010 2011
2017 2018 2019
Year
Annual
2012 2013
2014 2015 2016
Rainfall
361
408
217
324
510
488
275
392
296
420
(mm)
Annual
Runoff
(mm)
145
160
90
130
205
195
110
157
120
165
3. The figure below shows 5 different isohyets in a watershed. Find the average rainfall using the
isohyetal method
Given: The left-most side area (Zone A) can be assumed to receive a rainfall of 1 cm. The area between
the isohyets are given in the following table:
A
Zone
A
B
C
D
E
F
B
1 cm
D
E
1.5 cm
4 cm
Area (km²)
80
75
95
82
68
5
2.5 cm
3.5 cm
You have been given a 1-hour unit hydrograph (1 unit
= 1 cm) and have been asked to use it to derive the
surface runoff hydrograph for a 2-hour storm for
which the total depth of rainfall excess was X cm
and the intensity was constant. To derive it, you can:
Multiply the ordinates of the 1-hour unit
hydrograph by X/2
Find the 2-hour unit hydrograph and then
multiply its ordinates X/2
Consider the storm as having two 1-hour
periods of depth X/2 , multiply each 1-hour UH
by X/2, lag them by 1 hour, and then add their
ordinates.
Multiply the ordinates of the 1-hour unit
hydrograph by 2X
Chapter 16 Solutions
MindTap Engineering for Garber/Hoel's Traffic and Highway Engineering, 5th Edition, [Instant Access], 1 term (6 months)
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