Question

The following statements (C1, C2, C3, C4) pertain to the characteristics of different type of canals. Which of the following statements is/are correct?

C1: A contour canal can irrigate command areas on both the banks.

C2: It is possible to construct a contour canal with banks on one side only.

C3: In the case of a ridge canal, the number of cross drainage works are maximum.

C4: Side slope canal is aligned roughly at right angles to the ground contours.

1. C2 and C4 only
2. C1, C3 and C4 only
3. C1 and C3 only
4. C1 only

Answer 1

Correct Answer - Option 1 : C2 and C4 only

Concept:

Contour Canal:

• A canal aligned roughly parallel to the contours of the area is called a contour canal.
• This type of canal can be seen in hilly regions.
• Since it is parallel to the contour line, the ground on one side of the canal is higher and hence irrigation is possible only on the other side of the canal.
• A contour canal has to pass the drainage and hence cross drainage works are required to be provided.

Ridge Canal:

• A canal aligned along the ridgeline or watershed line of an area is said to be a ridge canal or watershed canal.
• Since it is running at the peak altitude of the area, irrigation on both sides of the canal up to a larger extent of the area is possible.
• There is no interception of natural drains on ridgelines hence, no cross drainage works are required for this type of canal.

Side Slope Canal:

• A canal aligned nearly perpendicular to the contour of the area is called a side-slope canal.
• It is located neither on the ridgeline nor on the valley line but is approximately in between them.
• It is parallel to the natural drainage line and hence no cross drainage works are required.
• The bed slope of the side slope canal is very steep.