HEC-HMS T4 | How to Estimate Design Flood in HEC HMS of ungauged Basins - An Integrated Solution

[@lalkhan162]

Thank you, sir, for making and sharing this valuable tutorial for HEC-HMS learners.

[@mdtareqaziz645]

Thank you so much Sir for the detailed tutorial.

[@suseendar]

Thank you sir , I was stuck on how to model 2D flood mapping for a location which does not have any observed data. your tutorial was very helpful to overcome the problem.

[@geologistdinesh]

Great butr you not put CN global link and other documents folder for learning proposed

[@AliUsman-w9l3t]

Randhawa sb, its v good tutorial... 👌👌

[@salmanrandhawa5496]

Thanks

[@etarijoy6566]

Finally, thank you Sir for this tutorial, now I can model for an unguaged basin using the Lag routing method. But one question, for a basin as large as 20,000sqkm, can one also apply this method.

[@etarijoy6566]

Hi Sir, thank you so much for this, this is just what I have been looking for for a basin with no observed flow. But sir, is the excel sheet used for the calculation of lag time of concentration for basin and reaches and lag time using kirpich formulae available or a link to where I can get the formulae used would be appreciated.

[@agrajkhakurel5320]

Thanks for this valuable information. Can you please elaborate on how to get the hyetograph for gages?

[@salmanrandhawa5496]

Ok, I will make a separate tutorial on design hyetograph development for a watershed.

[@etarijoy6566]

Please Sit, is there a way we can validate the simulation result for basins without observed discharge data?

[@walonichts3137]

thank you

[@suseendar]

Hi Sir , I see you are using 0.60Tc for lag time in reach routing, In reaches the time concentration itself is the time of travel from start to end reach. Can we directly use this Tc value as the lag time ?

[@salmanrandhawa5496]

Both are empirical. Tc is the travel time of the droplet of water whereas lag travel time of flow.

[@clsanchez77]

Further, lag time is defined in the HEC-HMS reference manual as the time between the centroid of precipitation and peak flow, which is suggested as 0.6 Tc. It is a parameter you can calibrate if you have sufficient observed data.