What type of losses can be mainly avoided by lining the canals?

Civil Engineering : Irrigation - Quiz(MCQ)

Seepage Losses

Evaporation Losses

Erosion of Canal Bed

Discharge Losses at Branch Canals

Correct Answer : Seepage Losses

Explanation : If lining is not provided in the canal then irrigation water is lost in the form of percolation and absorption as seepage losses. This loss is very significant as it reduces the potential of the irrigation water, which is a costly commodity. So, in order to reduce seepage losses the lining of the canal is needed.

Recently Updated in Irrigation Questions

Which type of lining is mixed and placed under temperature?

Dry Stone Lining

Shotcrete Lining

Cement Concrete Lining

Asphaltic Concrete Lining

Correct Answer : Option (D) : Asphaltic Concrete Lining

Explanation : Asphaltic concrete lining has been under evolution. It is used in very few places. This concrete is a careful mixture of asphalt and graded stone aggregate, and is mixed and applied under elevated temperature. This is a flexible lining and readily confirms to subgrade.

Calculate hydraulic mean depth for concrete-lined channel to carry a discharge of 350 cumecs at a slope of 1 in 5000. The value of manning’s constant for the lining is 0.015. The side slopes of a channel may be taken as 1.5:1. Assume limiting velocity in the channel as 2m/sec.

2.20 m

2.40 m

2.60 m

2.80 m

Correct Answer : Option (D) : 2.80 m

Explaination : Using Manning’s equation: V = 1/n.R2/3.S½
2 = 1/0.015 x Râ…” x 1/5000½
R = 2.80 m.

What is the maximum permissible velocity in Cement concrete lining (Unreinforced) as per Indian Standards?

1.2 to 1.8 m/sec

2 to 2.5 m/sec

1.5 to 2 m/sec

1.5 to 2.5 m/sec

Correct Answer : Option (B) : 2 to 2.5 m/sec

Explanation : The maximum permissible velocity for unreinforced cement concrete lining is 2.0 to 2.5 m/sec. For Boulder lining, the maximum permissible velocity is 1.5 m/sec.