Scaling Rain Data for a Design Storm

[Eft03]

Is there a simplified method to scale rain data to an appropriate design storm?

I have rain data from three-nearby rain gauges, which indicate two large rainfall events, 6- and 12-hours. These occurred around the time when the remnants of Hurricane Ida moved through the area.

At the same time, I have flow data from a sewer collection system and from pump stations. What I would like to do is scale the rain data for comparison to a 24-hour storm, but I am not sure if there is a simplified way to do this, or if it is even possible.

 

[psmart]

You could extract the center of the observed data to create a shorter event, but extending your 6 or 12 hour rainfall observations to generate a 24-hour event is speculative at best. Your 12-hour observations could even exceed the established 24-hour depth you're using for comparison!

Why not compare your observed rainfall to a synthetic rainfall distribution of the same duration? For example, if you wanted to compare to a Type II distribution, 6-hour and 12-hour versions available, in addition to the prevailing 24-hour duration.


Peter Smart
HydroCAD Software

http://www.hydrocad.net