Question

(a) A 1 m-high broad-crested weir controls flow in a river channel that is approximately rectangular in section with width 10 m (Figure Q1). The bed slope is 1:1000 and

the Manning coefficient is estimated to be 0.025 s/m13. Given that the coefficient of discharge for the weir is 0.85, and assuming a 5% loss in flow energy over the weir, calculate the flow depth immediately upstream of the weir (section A in FigureQ1) and immediately downstream of the weir (section C) for a discharge of 20m/s. Neglect bed level differences between A and C for this calculation.

Fig: 1

Fig: 2