Sediment Transport and Irrigation Channels Design topics include: Irrigation canal design capacity, sediment load, bed and suspended load and also their measurements, sediment transport importance and its mechanics, non scouring design methods, india stable channels, irigation canal cross section and maintenance.   Sediment transport: Understanding the behavior and transport of sediment is important for designing irrigation systems. For example, sediment transport in irrigation canals can affect the sustainability of an irrigation system. Unwanted erosion or deposition can lead... Show more

Sediment Transport and Irrigation Channels Design topics include: Irrigation canal design capacity, sediment load, bed and suspended load and also their measurements, sediment transport importance and its mechanics, non scouring design methods, india stable channels, irigation canal cross section and maintenance.
 

Sediment transport: Understanding the behavior and transport of sediment is important for designing irrigation systems. For example, sediment transport in irrigation canals can affect the sustainability of an irrigation system. Unwanted erosion or deposition can lead to:
Increased maintenance costs: Unfair, unreliable, and unequitable distribution of irrigation water
Irrigation canal design: Irrigation canals are usually designed based on the assumption of uniform and steady flow of water and sediments. However, the flow is predominantly non-uniform, due to time-dependent discharges and constant water levels at regulation and division points.
Sediment transport concepts: The underlying concepts of sediment transport, such as the development of bedforms and friction factors, were developed for the conditions that specifically prevail in a natural stream.
Artificial channels: Artificial channels should be properly designed, and should not fail to carry the sediment load admitted at the canal head works.
Tunnel-type sedimentcluder: In such excluders, the sediment-laden water, which flows mainly near the bed, is made to flow through the tunnels provided at the canal bed. 

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Irrigation Engineering Practice Test: Sediment Transport and Irrigation Channels Design

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25 Questions

1. Which structure is provided when the disposition of earth becomes costlier?

Back BermSpoil BanksFreeboardBorrow pits

2. Determine the discharge required at the head of the distributary in a canal where Kharif area to be irrigated is 2400 hectares and Rabi area to be irrigated is 1800 hectares, for fulfilling maximum crop requirement. Assume suitable values for kor depth and kor period.

2.2 cumec2.1 cumec2 cumec2.08 cumec

3. Which type of structure does the diagram represent?

BermFreeboardBorrow PitSpoil Banks

4. The sediment confined along and above the bed up to a depth ‘2d’ (d being grain size) is treated as bed load.

MaybeDon't KnowTrueFalse

5. Design a channel carrying a 30 cumecs. The median grain diameter is taken as 0.5 mm. The bedload concentration is 60 p.p.m by weight. Use Lacey’s Regime perimeter and Meyer-peter’s formulas.

B = 24 m, S = 1/5500, y = 1.45 mB = 25 m, S = 1/5700, y = 1.35 mB = 22 m, S = 1/5800, y = 1.55 mB = 26 m, S = 1/5600, y = 1.25 m

6. Which of the following is not a reason which leads to a canal breach?

Due to leakage or pipingDue to faulty design and construction of banksDue to the maintenance of service roadsDue to intentional cuts made by cultivators

7. What cause is prime responsible for the heavy movement of water from main canal to branch canal?

Existence of Favorable GradientDepth of the CanalType of FlowVelocity of Flow

8. The shear stress required to move grain on the side slopes is less than the shear stress required to move the grain on the canal bed.

TrueMaybeDon't KnowFalse

9. Calculate the ratio of the tractive critical stress to the average shear stress if the water flows at a depth of 0.8 m in a wide stream having a bed slope of 1 in 3000. The median diameter of the sand bed is 2 mm.

1.530.530.861.86

10. The soil is assumed to be coherent in the study of the mechanism of sediment transport.

MaybeDon't KnowFalseTrue

11. What is provided as a measure of safety during driving?

FreeboardService RoadsBanksDowlas

12. The berms help in checking excessive loss of water due to seepage.

FalseDon't KnowMaybeTrue

13. Whose theory was the first to provide semi-theoretical analysis of the problem of incipient condition of bed motion?

Shield’s theoryLacey’s theoryKennedy’s theoryStrickler’s equation

14. Let us take the gross commanded area of a watercourse is 2000 hectares, 80% of which is culturable irrigable. Intensities of sugarcane and paddy are 30% and 50%. The duties of the crops at the head of the watercourse are 850 hectares/cumec and 1900 hectares/cumec. Find the discharge required at the head of the watercourse?

0.97 cumec0.986 cumec0.9 cumec0.98 cumec

15. Based on his research what factor is given by Kennedy for free silting and scouring actions in a channel?

Rugosity CoefficientBed Slope of ChannelCritical Velocity (Vo)Hydraulic Mean Depth

16. What is the minimum size of the bed material that will remain at rest in a channel?

d < or = 11 R.Sd = 11 R.Sd > or = 11 R.Sd > 11 R.S

17. The actual capacity of silt laiden water channel is worked out with 1/2 : 1 side slopes.

FalseDon't KnowTrueMaybe

18. Commonly the bed load is 10% of total suspended load.

TrueFalseMaybeDon't Know

19. The scouring and silting on the river banks raise the flood levels for the particular discharge.

Don't KnowMaybeFalseTrue

20. Which type of state is achievable in artificial channels but not in rivers?

Laminar StateRegime StateTurbulent StateUniform State

21. On which factor does the movement of bedload depends?

Type of FlowVelocity of FlowDepth of FlowWidth of the River

22. For the bed of the canal, the average shear stress is equal to the tractive force per unit area.

TrueDon't KnowFalseMaybe

23. BEAST Stands for _______________

Benthic Environmental Assessment Sediment ToolBenthic Environmental Achievement Sediment ToolBenthic Erosion Assessment Sediment toolBenthic Environment Achievement Sediment Task

24. For the usual turbulent flow, calculate the critical shear stress if the mean diameter of the grain particle of bed material is 0.3 mm.

0.300 N/m20.116 N/m20.206 N/m20.106 N/m2

25. The water flows at a depth of 0.6 m in a wide stream having a bed slope of 1 in 2500. The critical tractive stress is 0.53 N/m². Determine the motion of soil grains and the average shear stress.

2.35 N/m2 and soil grains is in motion0.235 N/m2 and soil grains is in motion0.235 N/m2 and soil grains will be stationary2.35 N/m2 and soil grains will be stationary