Hi everybody.
I’m new to the forum and don’t know if this has been answered before.
I’m using Hec-Ras to solve one of the examples, in particular Critical Creek (Critcrek.prj).
I can’t understand how is conveyance calculated for the left overbank.
While it is calculated correctly for the main channel and right overbanks as K=1.486/n*A*R^(2/3), this doesn’t hold for the left overbank.
This continues for all 12 sections but the maximum error is for section 2 (6.26%).
Here are the numbers for the second section as copied from the table:
Area left 2086.7
Area channel 236.92
Area right 0
W.Perim left 641.54
W.Perim channel 48.61
W.Perim right 0
H.Radius left 3.25264 OK
H.Radius channel 4.8738 OK
H.Radius right 0.66199 OK
Conveyance left 72617 (1.486/0.1*2086.7*3.25264^(2/3)=68072.2)
Differece = 4544.8 WHY ????
Conveyance channel 25300 (1.486/0.04*236.92*4.8738^(2/3)=25301) OK
Conveyance right 0 (1.486/0.1*0*0^(2/3)=0) OK