Flow in a rectangular channel using the Strickler equation

Channel slope [m/( 1000 m), (per thousand)]
Roughness [mm]
Channel bottom width [m]
Flow depth [m]
kSt= 77 [m^(1/3)/s]
v = 4.8410 [m/s]
Q = 9.6821 [m3/s]

Physical Model:

kSt = 26/kb^(1/6) ... [kb] = [m]

v = kSt * Rhy^(2/3) * I0^(1/2)