9. Regime Canal
A Canal is said to be in a state of regime
If there is no sitting
Velocity of water in channel is greater than
critical velocity.
10. Design of Unlined Canal
Unlined canal is designed by Two theories.
Kennedy’s Theory
Lacey’s Theory
11. Design of Unlined Canal
Unlined canal is designed by Two theories.
Kennedy’s Theory
Lacey’s Theory
12. Kennedy’s Theory
Theory given in 1895.
Kennedy has conducted experiments on a number of sites on
the upper Bari Doab canal system (At that time in Punjab
but now in Pakistan), made the observations as a result of
study of data over 30 years, as given below.
(a) Flowing water has to counter act some amount of friction
against the bed of the canal.
(b) Friction to the flowing water gives rise to vertical eddies
rising up smoothly to the surface from base of canal.
(c) Generation of eddies are responsible for keeping most of
the silt in suspension.
23. Lacey’s Theory Drawbacks
i. All formulae are empirical.
ii. True regime conditions cannot be easily achieved
in reality.
iii. Silt friction factor f varies on different factors.
iv. Characteristics of regime channel are not defined
precisely.
v. Concept of semi-elliptical c/s of a regime channel
has limited Acceptance.
vi. Perfect definitions of silt grade and silt charge are
not given.
