owillis28
Well-known member
Anybody have additional sample problems dealing with unit hydrographs, hydrograph separation or hydrograph synthesis? The NCEES sample question & solutions book did not include any problems involving hydrographs.
Hydrology Questions for the PE Exam
- Thread starter owillis28
- Start date
Help Support Professional Engineer & PE Exam Forum:
G
Guest
Chelapati Example problem 1 (4.7.1)
You have been requested to compute the discharge for design of a bridge opening through a major highway. Flow records available at the site permit development of a unit hydrograph for the drainage area. It is therefore determined that the design discharge should be computed using the unit hydrograph technique. The information provided to you is as follows:
1. Drainage area upstream from bridge site = 43 sq miles
2. Flood hydrograph peak discharge = 9300 cfs
3. Flood hydrograph volume = 3260 acre-ft
4. Duration of runoff-producing portions of storm that produced flood hydrograph = 2 hours. (This indicates that th enet rain occurred in 2 hours).
Required:
A. From the data furnished, computer 2-hr unit hydrograph peak discharge.
B. The criteria for determining the bridge opening has been established to be the flood produced by 2.5-in of runoff occuring over a 2-hr period of time from the 43 sq mile drainage area.
i. What is the design discharge?
ii. What is the design flood hydrograph volume?
A. Qpeak = 6550 cfs
B. i. Qdesign = 16,375 cfs
B. ii. Vdesign = 5,733 acre-ft
Post follow-up if you have any questions.
JR
You have been requested to compute the discharge for design of a bridge opening through a major highway. Flow records available at the site permit development of a unit hydrograph for the drainage area. It is therefore determined that the design discharge should be computed using the unit hydrograph technique. The information provided to you is as follows:
1. Drainage area upstream from bridge site = 43 sq miles
2. Flood hydrograph peak discharge = 9300 cfs
3. Flood hydrograph volume = 3260 acre-ft
4. Duration of runoff-producing portions of storm that produced flood hydrograph = 2 hours. (This indicates that th enet rain occurred in 2 hours).
Required:
A. From the data furnished, computer 2-hr unit hydrograph peak discharge.
B. The criteria for determining the bridge opening has been established to be the flood produced by 2.5-in of runoff occuring over a 2-hr period of time from the 43 sq mile drainage area.
i. What is the design discharge?
ii. What is the design flood hydrograph volume?
A. Qpeak = 6550 cfs
B. i. Qdesign = 16,375 cfs
B. ii. Vdesign = 5,733 acre-ft
Post follow-up if you have any questions.
JR
owillis28
Well-known member
JR,
Your problem was pretty straight forward. I was wondering if you could take a look at my solution to see if I have missed anything. My units were different from the units in your answers.
Matt
Your problem was pretty straight forward. I was wondering if you could take a look at my solution to see if I have missed anything. My units were different from the units in your answers.
Matt
G
Guest
Matt --
Everything looks straight to me. The units for 6550 cfs aren't straight forward because you are using proportionality to arrive at the answer, so in actuality, you are getting 6550 cfs per in volume. It is weird but just an artifact of the solution.
Just a few more days .. keep the faith !! :true:
JR
B
bpanama
Just registered so I can't open a new topic so I'm replying here:
Been reading all of the threads and there is some really good stuff here. Thanks for having this.
I found a nice glossary of water terms on a local municipality's website I thought some of you could use:
http://www.kcmo.org/water-ed/glossary.htm
Good luck next Friday everyone!
Been reading all of the threads and there is some really good stuff here. Thanks for having this.
I found a nice glossary of water terms on a local municipality's website I thought some of you could use:
http://www.kcmo.org/water-ed/glossary.htm
Good luck next Friday everyone!
Similar threads
