Hi;
DOCX
I used SCS method in Civilstorm and compared the results of Peak Discharge with the manual calculation and it shows difference, what is the reason?
also is there any way to enter the Swamp and pond factor in the model Fp?
How I can view the unit peak Discharge in the results?
How I can view the initial abstraction value in the results ?
I attached the model and the manual calculation for your refernce
Regards
Sayed Elhagar
CivilStorm Model.zip
Hello Sayed,
I am not quite certain, but it looks like your hand calculations might be using the TR-55 method, which is not the same as the SCS Unit Hydrograph Method being used in the CivilStorm model. You can read about the difference in our Stormwater Conveyance Modeling and Design book. (sections 5.4 & 5.5) The TR-55 method I believe you are using is a method of estimating peak flow, whereas the SCS Unit Hydrograph method computes a runoff hydrograph. Each have different methodologies.
The "swamp factor" needs to be accounted for by adjusting the CN. See:
How do I apply the 'Swamp Factor' when using the SCS Unit Hydrograph or the Tabular TR-55 methods?
The catchment results for the SCS Unit Hydrograph method do not include "unit peak discharge" or the IA. Initial Abstraction is accounted for though. See:
How is Initial Abstraction considered with the SCS Unit Hydrograph method?
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.