Water Conveyance Loss and Designing Conveyance System - Practices of Irrigation and On-farm Water Management - page 33

- Water Resources Management
- Water Resources Research
- Irrigation Science
- Trans. ASAE
- Irrigation and Drainage System

Questions

(1) What is seepage? What are the factors affecting seepage in earthen conveyance
system?
(2) Describe in brief the different methods of seepage measurement.
(3) How can the average seepage loss in an irrigation command area be estimated?
(4) Discuss the various means of reducing seepage in an earthen channel.
(5) How will you decide on lining a canal?
(6) What are the different configurations/geometries of irrigation channel?
(7) Define the following: permissible velocity, wetted perimeter, hydraulic radius,
freeboard, and side slope.
(8) Describe Chezy's and Manning's equation for calculating velocity in open
channel.
(9) What is the most economical cross-section of a channel?
(10) Derive the conditions for the most economical cross-section for (i) trapezoidal
and (ii) rectangular channel section.
(11) Determine the velocity of flow and discharge capacity of an unlined canal
section on a grade of 1 m on 900 m having depth of flow 1.2 m, bottom width
0.9 m, and side slope 1.2:1.
(12) Design an earthen channel of trapezoidal section for the following conditions:
Discharge 2.5 cumec

Channel bottom slope: 1 in 1,400
Side slope: 1.25:1
Va l u e o f N in Manning's equation

=

=

0.022
(13) Design a concrete canal from the following information:
Discharge

= 50 cumecs

Slope 1in3,600

Side slope

=

1:1( H : V )
Va l u e o f N in Manning's equation

=

= 0.011

(14) Draw the velocity diagram of pipe flow.
(15) Draw the hydraulic and energy grade line of pipe flow.
(16) What do you mean by “head loss” in pipe flow? What are the factors affecting
head loss? How can the head loss be minimized?
(17) Write down the principles of selecting pipe size for irrigation purposes.
(18) Determine the head loss due to friction in an irrigation pipe having 300 m
length and 30 cm diameter. The velocity of flowing water in the pipe is 2.5 m/s.
(19) Compute the size of best quality concrete pipe that will carry 0.05 m 3 /s
discharge with a head loss of 1 m per 1,000 m.