Question

The length of the weir will not exceed the bed width of the canal upstream, in case of trapezoidal notch fall.

(a) True

(b) False

I had been asked this question during an interview.

I'm obligated to ask this question of Canal Falls in portion Canal Falls of Irrigation Engineering

Answer 1

Right answer is (a) True

To explain: In this type when the notch is provided there is heading up or drawdown of water level in the canal near the fall. Therefore the whole width of the canal is divided into number of notches. The crest is kept higher than the bed level of the canal, but in no case the total length of the weir will not exceed the bed width of the canal upstream.