Canals - Short Questions & Answers

Canals - Short Questions & Answers Points :Canals Short Questions and Answers Q.1: Define the term of canal. Ans : A canal is an artificial channel, generally trapezoidal in shape constructed on the ground to carry water to the fields either from the river or from a tank or Reservoir. Canals can be Classified in following says. Q.2: Write down the classification of canal based on the nature of source of supply. Ans : A canal is said to be permanent when it is fed by a permanent source of supply. The canal is a well made up regular graded channel. It has also permanent masonry works of regulation and distribution of supplies. A permanent canal is also sometimes known as perennial canal when the sources from which canal takes is an ice fed perennial river. Q.3: Write down the difference between permanent and Inundation canal. Ans : Inundation Canals usually draw their supplies from rivers whenever there is a high stage in the river. Q.4: Write down the name of classification of canal based on financial output. Ans : (i) Productive canal.
(2) Protective canal. Q.5: Explain the difference between productive arid protective canal. Ans : Productive Canals arc those which yield a net revenue to the nation after full development of irrigation in the area. Protective canal is a sort of relief work constructed with the idea of protecting a particular area from famine. Q.6: Write down the name of classification of canal based on the function of the canal Ans : (1) Irrigation canal.
(2) Carrier canal.
(3) Feeder canal.
(4) Navigation canal.
(5) Power canal. Q.7: Write down the name of canal classification based on the discharge. Ans : Classification based on the discharge and its relative importance in a given network of canals

(1) Main canal.
(2) Branch canal.
(3) Major distributary.
(4) Minor distributary.
(5) Watercourse. Q.8: Write down any four factors grooving alignment of a canal. Ans : 1) The alignment of the Canal should be such as to ensure
(i) The Most economical way if distributing the water to the land,
(ii) as high a command as possible and
(iii) minimum number of Cross drainage works.

2) The alignment of a canal on a watershed, being the most economical is preferred. As a general rule, all tile watershed lying in a command should be occupied by distributaries

3) The length of the main canal from the point where it takes off from a river to a point where it mounts on a watershed should be minimum.

4) The contour alignment should be changed this was or that way in order to reduce the number of cross-drainage works to a minimum.

5) The alignment should avoid villages, roads, can. tracks, cremation places, places of worship and other valuable properties

6) The alignment should pass through the balanced depth of cutting. If not. It should involve minimum depth of cutting or minimum height of filling.

7) The number of kinks and acute curves should be minimum.

8) Ideal length of canal should be minimum and branches etc. should be economically planned.

9) The alignment should not be made in a rocky, brackish or cracked strata, Q.9: Write down the lining of canal necessary. Ans : Lining of canal is necessary
5. To minimize the seepage losses in canal.
6. To increase the discharge in canal section by increasing the velocity.
7. To prevent erosion of bed and side due to high velocities.
8. To reduce maintenance of canal. Q.10: Write down the name of Important type of concrete lining. Ans : The following are the important types, of concrete lining used in Pakistan:

(a) Hard surface type lining:
1. Cement concrete lining.
2. Shotcrete lining
3. Precut concrete lining.
4. Cement mortar lining.
5. Brick lining.
6. Stone blocks, or undressed stone lining.
6. Asphaltic lining.

(b) Earth type lining:
1. Soil cement lining.
2. Clay puddle lining.
3. Sodium carbonate lining.

(c) Buried and protected membrane type lining:
1. Prefabricated light membrane lining.
2. Bentonite soil and clay membrane lining.
3. Road oil lining.
4. Concrete lining