Description of the Main Aspects of the Regime Theory - Sediment Transport in Irrigation Canals: A New Approach - page 266

Lacey for m = 2 and d = 0.4 mm

2.0 0.00008

1.5 0.00006

1.0 0.00004

0.5 0.00002

0.0 0.00000

0 5 10 15

Discharge Q

y
S 0

Lacey for m = 2 and d = 0.15 mm

2.0 0.00008

0.00006

1.5

0.00004

1.0

0.5 0.00002

Figure D.1. Example of the
design of an earthen canal
according to the Lacey method
for m = 2 and for d = 0.04 mm
and for d = 0.15 mm.

0.0 0.00000

0 15

5 10

Discharge Q

y
S 0

D SOME REGIME CONSIDERATIONS

D.1 SEDIMENTS

In general, irrigation canals have a less steep bottom slope, smaller cross
sections and discharge than the rivers, which supply the irrigation water
to the canal network. This means that the canals have a smaller sediment
transport capacity than the parent river. Therefore, an important aspect in
the design and operation of these canals is to consider sediment exclusion
at the head works or sedimentation in silting ponds. The location and crest
level of canal regulators at the head works should limit the sediment entry
into the canal network.

D.2 MATURING OF CANALS

The maturing of canals is an important aspect in view of the operation and
maintenance of canals. The canal design according to the regime theory