Question

What is formula used to determine the crest level while designing a sarda type fall?

(a) Q = Cd x \(\sqrt{2g}\) x L x H^3/2 x (H/Bt)^1/6

(b) Q = Cd x \(\sqrt{2g}\) x L x H^3/4 x (H/Bt)^1/4

(c) Q = Cd x \(\sqrt{2g}\) x L x H^1/4 x (H/Bt)^1/8

(d) Q = Cd x \(\sqrt{2g}\) x L x H x (H/Bt)^1/6

The question was posed to me in a dream while sleeping

Enquiry is from Canal Falls topic in portion Canal Falls of Irrigation Engineering

Answer 1

The correct answer is (a) Q = Cd x \(\sqrt{2g}\) x L x H^3/2 x (H/Bt)^1/6

To elaborate: Discharge formula is used to determine the crest level.

Q = Cd x \(\sqrt{2g}\) x L x H^3/2 x (H/Bt)^1/6, where Cd = 0.415 for rectangular crest and 0.45 for trapezoidal crest, L = length of crest, Bt = Top width of crest, height of crest above bed = y – H, y = normal depth of channel.