A rectangular channel 8 m wide carries a discharge of 0.9 m3 /s. At a certain section, the channel lining changes from rough to smooth. The normal depths in the rough and smooth reaches are 0.6 m and...

A rectangular channel 8 m wide carries a discharge of 0.9 m3 /s. At a certain section, the channel lining changes from rough to smooth. The normal depths in the rough and smooth reaches are 0.6 m and 0.4 m, respectively. The channel slope is 0.8%. Using a single step of the direct step method, estimate the length of the reach of nonuniform flow.