Test: Canal Regulators- 1 - Civil Engineering (CE) MCQ

A canal outlet or a module is a small structure built at the head of the watercourse so as to connect it with a minor or a distributary channel.

A good irrigation module should fit well to the decided principles of water distribution. It should be simple and cheap. It should draw its fair share of silt.

Sensitivity is defined as the ratio of the rate of change of discharge through the outlet to the rate of change of water level of the distributary, referred to the normal depth of the channel.

Rigid modules or modular outlets are those through which the discharge is constant and fixed within limits irrespective of the fluctuations of the water levels of either the distributary or of the water course or of both .
∴  sensitivity = 0, and flexibility = 0.

The outlet is said to be proportional when the rate of change of outlet discharge equals the rate of change of channel discharge.
∴ outlet is, 'proportional' when flexibility’ equals unity.

Pipe outlet discharging freely into the atmosphere is the simplest and the oldest type of a flexible outlet. The discharge through such an outlet will depend only upon the water level of the distributary, and will be independent of the water level of the watercourse.