how to find 500 inflow hydrograph by HEC HMS

[engrsalah]

i have to find peak discharge and inflow hydrograph while i have 500 year return period rain fall which is 10.14 in. my catchment area is 32.43 mi^2. curve number is 85. time of concentration is 1.22 hr. my question is how to find inflow hydrograph in HEC HMS while i have these data?? and how to distribute rain fall is scs type 2 method i use?

 

[BigInch]

The Water Distribution forum may be more apt to answer your question.

 

[cvg]

this is a storm/flood engineering forum question. the question is far too broad to answer. It sounds as if you have all the data you need and you can distribute the rainfall any way you wish. I would recommend critically centering the rainfall over the watershed to produce the maximum peak or to produce the maximum volume as necessary. For such a large watershed, you may need to estimate aerial reduction. Rainfall distribution is generally related to your local climate, you will need to make your own decision on which type is most appropriate. You may want to consider a storm duration longer than 24-hours.