If we assume a long and resistance equations at its inlet are appli-critical sloped channel, the two equations are the energy equation and the critical depth criterion. Here it is convenient to assume initially a long and critical slope channel. Since the channel is of rectangular cross section yc =2/3 H =1m Therefore, from the resistance equation(uniform flow depth yc) the critical slope Sc = 0.00256 >So=0.0001 (see Example 8.25). Hence the channel is of mild slope; if we still assume it is ong, we now can obtain the corresponding uniform flow rate, Qo, from the energy and resistance equations.