Hydrology Question

[bigray76]

I am taking the Transpo PM - do I need to know anything about runoff other than the rational method? Do I need to get familiar with SCS / NCRS and CN numbers, etc.? This came up wehn I figured I would try to do a fair number of the NCEES sample afternoon Water questions. Some seem to draw on some pretty specific references that I don't have. Any direction on this would certainly be appreciated.

Thanks.

Ray

 

[north6633]

I am taking the Transpo PM - do I need to know anything about runoff other than the rational method? Do I need to get familiar with SCS / NCRS and CN numbers, etc.? This came up wehn I figured I would try to do a fair number of the NCEES sample afternoon Water questions. Some seem to draw on some pretty specific references that I don't have. Any direction on this would certainly be appreciated.
Thanks.

Ray

I am in the same boat Ray. So thanks for posing the question. I know the the CERM does not cover everything you need for Water Resource or Geo. Be nice to know of some good references that would help in this area.

 

[Guest]

If you look at the specification for the Civil PE Exam (NCEES), you are provided the following:

Civil (Breadth)

V. WATER RESOURCES 20%

A. Hydraulics – energy dissipation, energy/continuity equation, pressure conduit, open channel flow,

flow rates, friction/minor losses, flow equations, hydraulic jump, culvert design, velocity control.

B. Hydrology – storm characterization, storm frequency, hydrographs, rainfall intensity & duration, runoff analysis.

C. Water Treatment – demands, hydraulic loading, storages (raw & treated water).

Civil (Depth - Transportation)

III. WATER RESOURCES 20%

A. Hydraulics - Open channel flow, flow rates (domestic, irrigation, fire), flow equations, culvert design, velocity control

B. Hydrology - Rainfall intensity & duration, runoff analysis, flood plain/floodway

From the looks of it, you can potentially see hydrology topics that would include problems like CN Numbers (runoff analysis) in the Breadth or Transportation Depth. I think it is definitely worth some investment of your time (and patience) to become familiar with aspects of runoff problems like:

- Rational Method

- SCS Method

- CN values/application of CN #'s

- Time of Concetration formulae/methods

- Unit hydrograph

IMHO, I felt that CERM did NOT do a very good job in providing ample coverage of hydrology (runoff) problems. I supplemented my material with a reference book - Hydrology & Hydraulic Systems, Ram S. Gupta (ISBN 0881338656). This was a very good book in MANY respects, not just hydrology. If you can pick it up for cheap I would highly recommend it.

In terms of your immediate needs, you can find a supplement for runoff problems from the TR-55 reference manual. This manual can be located and downloaded from:

TR-55 Documentation - Go to Bottom of Page for link

I hope these responses help some - if you have any specific questions and would like to follow-up with a post I will do my best to answer.

Regards,

JR

 

[RIP - VTEnviro]

4:48 AM? I gotta ask, was this before you went to bed or after you got up?

I've got much more respect for the former than the latter.

I have nothing to add to this. You nailed the question better than I could, so I'll just poke fun at you instead.

Though I'm actually working with a professor at the local 2-year tech college here to develop a "stormwater technician" course. Not your full blown hydrology/hydraulics class we took, but a combo of theory and regulatory practice to churn out folks who can file SW permits here, which is a major task. For the most part, it can be handled by a tech rather than all the effort coming from PE and blowing out the budget.

If you're a SW buff, I may need to bounce some ideas off you to get some insight.

 

[Guest]

4:48 AM? I gotta ask, was this before you went to bed or after you got up?

I had not gone to bed at that time - I did not get to bed until about 8:30 AM. I have a bizarre sleeping disorder. Typically, I don't sleep more than about 3 hrs at any given time. :screwloose:
I also typically stay up 'late' because my wife works from 3 pm - 11 pm, she doesn't get home until about 12 am.

If you're a SW buff, I may need to bounce some ideas off you to get some insight.

I have been spending some time learning more about all things stormwater because I have some projects where surface water/sediments are believed to be contaminated from stormwater loading. I am probably not a 'buff' per se, but somewhat knowledgeable. I will PM you with e-mail if you would like to bounce some ideas off me.

JR

 

[jfusilloPE]

I posted some stormwater stuff on this site that I learned in a study course. I'll do some digging around and try to find it and post it here.

 

[jfusilloPE]

Found it.....

Here is some useful information that I got from a review class and used for the Civil/WR Exam. I wrote these into my CERM for quick reference.

Time of Concentration:

Kirpich Equation: Tc = (0.0078) x L^0.77 / S^0.385

Where L = length, feet and S = slope

Flood Probability:

Pf = 1 – (-1) x (1-R)^(1/n) x 100

Where R = acceptable risk and n = period of interest

R = % / 100

Unit Hydrograph:

Qp / Qh = Qo / Qt

Where: Qp = peak discharge

Qh = hydrograph peak discharge

Qo = measured peak discharge

Qt = hydrograph discharge at time, t

The Kirpich Equation was pretty useful.

 

[RIP - VTEnviro]

I have been spending some time learning more about all things stormwater because I have some projects where surface water/sediments are believed to be contaminated from stormwater loading. I am probably not a 'buff' per se, but somewhat knowledgeable. I will PM you with e-mail if you would like to bounce some ideas off me.

Got your contact info, thanks.

They recently tightened the threshold here for triggering a SW permit, so I've had to become the local expert because we had 3-4 projects in the past months that needed a permit. It just clicks pretty well with me so my boss has had me run with it.

We did a job at the local tech college here. The CE department head had us come up for lunch and give a talk to the class about the design/planning/permitting of the work.

After the lunch we met with the prof and he asked us what skills would be good for 2-year grads to have and we thought that would be a good one. So he asked us to do up a model curriculum for him.