A contraction transition (n = 0.015) from a trapezoidal earth channel (n = 0.035) to a rec...

A contraction transition (n = 0.015) from a trapezoidal earth channel (n = 0.035) to a rectangular concrete channel (n = 0.015) is 15.2 m (50 ft) long. The trapezoidal channel has a bottom width of 22.9 m (75 ft), 4H:1V side slopes, and a longitudinal slope of 0.001 while the rectangular channel has a bottom width of 15.2 m (50 ft) and a longitudinal slope of 0.0005. If the discharge rate is 283.3 cms (10,000 cfs), compute the water depth in each channel and the headloss in the transition based on the average friction slope and a contraction loss coefficient of 0.2. Com­pute the elevation of the invert of the trapezoidal channel at the beginning of the transition.