Water emerges from under a gate into a trapezoidal, concrete channel. The gate opening is 0.55 m. and the flow rate is 12 .6 m3/sec. The entry channel has a 1.5-m bottom width, side slopes of 1:1 (H:V), and a bottom slope of 0.015. Determine the channel and flow classification (e.g., M-1, S-2) and explain your supporting logic.