HEC RAS Output Accuracy

[alfarooq74]

Hello

I m using HEC RAS for a case study. After simulating the HEC RAS now i m n Model Calibration Phase.

Can some body tell me what is the limits of accuracies..in term of depth....e.g. +0.50 to -0.50 ....or..some other parameters.....

or how much accuracy we can achieve with HEC RAS....

Thanks for help in advance.

Regards

[MattZ]

The water surface calculation is 0.01 feet and that a real number stored in the computer is only accurate to 6 digits.

[alfarooq74]

Thanks for Help

In my case the output WS is upto +30 to -30 cm...is acceptable....becasue I am unable to calibrate it beyond this by Manning n value....

I think there is no other parameter which can be used for calibrating the model..

Regards

[MattZ]

You can calibrate a HEC-RAS model using various parameters including:

Manning's n
Expansion/contraction coefficients
Weir and gate coefficients
Entrance/exit loss coefficients

[cbobbi]

As well as using mannings n and other parameters mentioned below, I've also found that accuracy can be improved by adjusting the bedslope in the steady state model. We found that it is wise to check your bedslope estimates against something like a DEM (if you have one) or some other source, as the estimate you make simply from your transects may be a bit out.

Cheers