Civil Engineering (CE) Exam  >  Civil Engineering (CE) Questions  >  If a 4-h hydrograph of a certain basin has a ... Start Learning for Free
If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will be
  • a)
    equal to 80 m3/s
  • b)
    greater than 80 m3/s
  • c)
    less than 80 m3/s
  • d)
    between 40 m3/s and 80 m3/s
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s,...
View all questions of this test
Most Upvoted Answer
If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s,...
. Given below is the 4-hr U.H for a basin of 84 sq.km. Derive S-curve and find the 2-hr
unit hydrograph.
Time (hr) 0 2 4 6 8 12 16 20
Flow (m3/s) 0 1.22 4.05 6.75 5.67 3.37 1.35 0
Time
(hr)
0 1 2 3 4 5 6 7 8 9 10
Flow
(m3
/s) 0 400 2500 4400 6000 7000 6100 5200 4500 3800 3200
Time
(hr) 11 12 13 14 15 16 17 18 19 20 21
Flow
(m3
/s) 2700 2200 1800 1400 1100 800 600 400 200 100 0
Free Test
Community Answer
If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s,...
Explanation:

To understand why the peak ordinate of a 2-hour unit hydrograph for the same basin will be greater than 80 m3/s, let's first understand what a unit hydrograph represents.

A unit hydrograph is a hydrograph that represents the direct runoff resulting from 1 unit of rainfall excess (usually 1 cm) spread uniformly over the entire basin for a specified duration. It is essentially a scaled-down version of the actual hydrograph that represents the response of the basin to a unit input of rainfall.

1. Relationship between Duration and Peak Flow:
The duration of a hydrograph refers to the time it takes for the hydrograph to complete its rise and fall. Generally, the shorter the duration of a hydrograph, the higher the peak flow. This is because a shorter duration means that the rainfall is concentrated within a smaller time frame, resulting in a more rapid and intense response from the basin.

2. The 4-hour Hydrograph:
Given that the 4-hour hydrograph has a peak ordinate of 80 m3/s, it means that during the peak flow period of 4 hours, the basin is experiencing a maximum discharge of 80 m3/s. This indicates that the basin has a certain capacity to handle and transmit water during this 4-hour period.

3. The 2-hour Hydrograph:
Now, let's consider the 2-hour unit hydrograph for the same basin. Since it is a unit hydrograph, it represents the direct runoff resulting from 1 unit of rainfall excess spread uniformly over the entire basin for a duration of 2 hours.

Since the duration is shorter (2 hours) compared to the 4-hour hydrograph, the peak flow of the 2-hour unit hydrograph will be higher. This is because the rainfall excess is concentrated within a smaller time frame, resulting in a more intense response from the basin.

Therefore, it can be concluded that the peak ordinate of the 2-hour unit hydrograph will be greater than 80 m3/s.

Conclusion:
The correct answer is option 'B' - greater than 80 m3/s.
Explore Courses for Civil Engineering (CE) exam

Top Courses for Civil Engineering (CE)

If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer?
Question Description
If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer?.
Solutions for If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Civil Engineering (CE). Download more important topics, notes, lectures and mock test series for Civil Engineering (CE) Exam by signing up for free.
Here you can find the meaning of If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice If a 4-h hydrograph of a certain basin has a peak ordinate of 80 m3/s, the peak ordinate of a 2-h unit hydrograph for the same basin will bea)equal to 80 m3/sb)greater than 80 m3/sc)less than 80 m3/sd)between 40 m3/s and 80 m3/sCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Civil Engineering (CE) tests.
Explore Courses for Civil Engineering (CE) exam

Top Courses for Civil Engineering (CE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev