INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

hydrograph

hydrograph

(OP)
Respected
i want to know if i have two hydrograph of rainfall 15 minutes interval and 1 hour interval and correspondingly the same for hydrograph (15 minut and 1 hour respectively) which one will have the peak flood. 15 minute hydrograph or 1 hour hydrograph?

RE: hydrograph

If I understand your question properly, it depends on the watershed.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

RE: hydrograph

(OP)
Respected beej67
i little elaborate the question as follow.
i have a rainfall event for 24 hr. and i want to construct two flood hydro graph. if i use time interval 15 minute for one hydrograph and 1 hr for second hydrograph. having the same catchment. which one will have the peak flood. 15 minute hydrograph or 1 hour hydrograph?

RE: hydrograph

In general, the hydrograph with the smaller time increment will produce a higher peak flow which will be a better representation of the true instantaneous peak. As you increase the hydrograph time step, the peak flow will be understated because each point is an average over a longer time period. A general rule of thumb is to use a time step that is less than one-half the time-of-concentration.

Peter Smart
HydroCAD Software
www.hydrocad.net

RE: hydrograph

There are some softwares which will give you bogus results if your calculation time increment is not a multiple of the time increment in your hyetograph. I believe HEC-HMS used to be this way, although it's been a long time since I used it. So consider that.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close