Type II 72-hr Rainfall
Type II 72-hr Rainfall
(OP)
I was able to download and add Type II 48-hr.hcr storm to the HydroCAD Rainfall Library. Is there a way to Use the 6-hr, 12-hr, 24-hr, and 48-hr to derive the 72-hr storm? We are getting into Dam projects that require looking at PMP/PMF events.





RE: Type II 72-hr Rainfall
Otherwise HydroCAD can be used to generate a synthetic rainfall distribution based local NOAA data. For details please see www.hydrocad.net/rainfall/generation.htm This procedure allows you yo define the overall rainfall duration and the time of peak.
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: Type II 72-hr Rainfall
RE: Type II 72-hr Rainfall
Frankly, the text you quoted ("each possible duration up to 72 hours should be reviewed in order to determine the critical duration") tends to imply the use of the Rational method, and not the SCS/NRCS method. As such, the analysis would be based solely on IDF data and would not use a temporal rainfall distribution, 72-hour or otherwise. Again, a careful reading of the regulations is necessary.
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: Type II 72-hr Rainfall
RE: Type II 72-hr Rainfall
Peter Smart
HydroCAD Software
www.hydrocad.net