how do you generate a hydrograph?

[IGdawg]

Hi,
I was wondering what program do you use to generate a hydrograph. I just saw a hydrology report done by someone else and the person used Hydaflow Hydrographs Extension to design a detention basin. But the hydrgraph was manually input, so the engineer did not use Hydraflow to create the hydrograph. The hydrograph looked like a smooth bell curve. I think Hydraflow generates the triangular one. We use Modified Rational Method here in Southern California for smaller projects.

Do you have any idea which program was used, and where can I get it?

Thank you in advance!

 

[SMIAH]

HEC HMS, for example.

http://www.hec.usace.army.mil/software/hec-hms/download.html

 

[gbam]

Your local agency may have a specific Unit Hydrograph that is required for your location. You may want to refer to the original drainage report or standard drainage manual. I know that our state, county and city agencies all have unit hydrographs.

 

[beej67]

Before you go screwing around with software, download this and read it cover to cover:

http://www.cpesc.org/reference/tr55.pdf

That should explain where the "bell shaped curve" hydrographs come from.


Then go here:

http://www.wsi.nrcs.usda.gov/products/w2q/h&h/Tools_Models/WinTR55.html

That software is basic and right from the horse's mouth. After you understand how that stuff works, then move on to HEC-HMS or something similar.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com