Canal Falls topics include: Canal falls type and location, syphon well drop design, canal falls design for vertical drop fall, baffer or inglis fall.   A canal fall, also known as a weir or barrage, is a structure built within a water channel to control water levels and prevent erosion. Canal falls are used when the ground surface is not uniform throughout the canal's alignment. They are built to maintain a certain drop in the canal level and to carry water from higher to lower levels.  Canal falls can be built for different purposes, such as: Divert water for agricultural needs Generate... Show more

Canal Falls topics include: Canal falls type and location, syphon well drop design, canal falls design for vertical drop fall, baffer or inglis fall.
 

A canal fall, also known as a weir or barrage, is a structure built within a water channel to control water levels and prevent erosion. Canal falls are used when the ground surface is not uniform throughout the canal's alignment. They are built to maintain a certain drop in the canal level and to carry water from higher to lower levels. 

Canal falls can be built for different purposes, such as:
Divert water for agricultural needs
Generate hydropower 

Some types of canal falls include:
Ogee Fall: This design uses both convex and concave curves. It is generally recommended for canals, unless there is a sudden change in natural terrain to a steeper slope.
Rapid fall: This fall is suitable for even and long natural ground surface slopes. It consists of a long sloping glacis with a longitudinal slope.
Stepped fall: This fall consists of a series of vertical drops in the form of steps. It is suitable for places with very long sloping ground. 

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Irrigation Engineering Practice Test: Canal Falls

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25 Questions

1. By providing a natural drop in one drop _______________________

the quantity of balanced earthwork increasesthe quantity of unbalanced earthwork increasesthe quantity of unbalanced earthwork decreasesnumber of fall increases

2. Which type of fall is not adopted in India?

Inglis FallMontague Type FallRapidsOgee Fall

3. By what value the thickness of notch pier should not be less than the water depth?

Equal to water depthThree fourth of the water depthOne fourth of water depthHalf the water depth

4. Canal drop or canal fall is needed construction in the canal bed.

MaybeTrueFalseDon't Know

5. A canal fall is provided when the available natural slope is flatter than the designed bed slope of the channel.

Don't KnowMaybeTrueFalse

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

Q = Cd x \(\sqrt{2g}\) x L x H x (H/Bt)1/6Q = Cd x \(\sqrt{2g}\) x L x H3/2 x (H/Bt)1/6Q = Cd x \(\sqrt{2g}\) x L x H1/4 x (H/Bt)1/8Q = Cd x \(\sqrt{2g}\) x L x H3/4 x (H/Bt)1/4

7. In which fall the depth discharge relationship is unaffected?

RapidsTrapezoidal Notch FallStraight Glacis FallOgee Fall

8. In case of design of sarda type fall the length of crest is kept equal to ____________

water Depth in the Canalhydraulic Jump on the fallthickness of the Canalbed Width of the Canal

9. What type of crest width is provided in designing a straight glacis fall?

Deep CrestNarrow CrestShallow CrestBroad Crest

10. On what factor in case of branch canals, the construction site for a fall depends?

Cost of ExcavationTopographyCommanded AreaCost of fall

11. What number of major defects does the ogee fall have?

3412

12. What type of design does the figure represent?

RapidsSingle vertical drop fallSarda Type FallBaffle Fall

13. Which type of fall is suitable for 60 cumecs discharge and 1.5 m drop?

Montague Type FallStraight Glacis FallRapidsBaffle Fall

14. In case of branch canals and distributary channels, the falls are located with consideration to _________________

availability of earth materialcommand areatopographycost economy

15. For a canal that irrigates the area directly the fall should be provided at a location FSL outstrips the G.L before the bed of the canal comes into the filling.

MaybeDon't KnowTrueFalse

16. Canal drops are provided to _______________

dissipate excess land slopeincrease the driving head of flow of waterdissipate inadequate land slopedissipate the excess energy

17. What is the shape of upstream wings in design of baffle fall?

CircularTrapezoidalSquareRectangular

18. Consider the following statements.
I. Possibility of combining some other structure with a fall eg. regulator, road bridge etc.
II. Cutting and filling are required below and above the fall should not be necessarily equal.
III. The command should not be reduced due to the lowering of F.S.L and the fall may be located below the outlets.
Which of the following statement is correct for site selection of a fall?

I and IIIII onlyI onlyI and III

19. In case of designing a sarda type fall the shape of the crest has one boundary level.

TrueMaybeDon't KnowFalse

20. What type of fall does diagram represent?

Inglis FallStraight Glacis FallSimple Vertical Drop FallOgee Fall

21. What type of fall does the diagram depict?

Trapezoidal Notch FallStraight Glacis FallSimple Vertical Drop Type FallOgee Fall

22. On what term does the construction of a fall in the case of the main canal depend?

Cost of Excavation and Filling versus Cost of fallDischarge Capacity of the CanalTopographyLength of the Canal

23. What is the reason for the construction of baffle wall in baffle fall?

To Ensure Formation of JumpTo Reduce Soil ErosionTo Maintain Uniform Velocity FlowTo Ensure Uniform Discharge of the Flow

24. In what intervals the top width of the notch lies?

1/2 to full water depthFull water depth1/4 to full water depth3/4 to full water depth

25. The length of the weir will not exceed the bed width of the canal upstream, in case of trapezoidal notch fall.

FalseDon't KnowMaybeTrue