In the context of cross-drainage structures, the correct statement(s) regarding
the relative positions of a natural drain (stream/river) and an irrigation canal,
is/are
A
In an aqueduct, natural drain water goes under the irrigation canal, whereas in a super-passage, natural drain water goes over the irrigation canal.
B
In a level crossing, natural drain water goes through the irrigation canal.
C
In an aqueduct, natural drain water goes over the irrigation canal, whereas in a super-passage, natural drain water goes under the irrigation canal.
D
In a canal syphon, natural drain water goes through the irrigation canal.
In Aqueduct and Syphon aqueduct under irrigation
canal or canal passes over natural drain. In Super passage and Canal syphon or simply
syphon, natural drain passes over irrigation canal
or canal goes under natural drain. In level crossing, natural drain water goes through
the irrigation canal.
Question 2
An unlined canal under regime conditions along with a silt factor of 1 has a width of flow 71.25m. Assuming the unlined canal as a wide channel, the corresponding average depth of flow (in m, round off to two decimal places) in the canal will be ______________
R = D (for wide rectangular channel) \begin{aligned} &\begin{aligned} A f^{2} &=140\left(\frac{2}{5} f R\right)^{5 / 2} \\ (B D) f^{2} &=140\left(\frac{2}{5} f \times D\right)^{5 / 2} \\ (71.25 \times D) \times 1 &=140\left(\frac{2}{5} \times 1 \times D\right)^{5 / 2} \\ D \times 0.5089 &=\left(\frac{2}{5}\right)^{5 / 2} \times(D)^{5 / 2} \\ D^{3 / 2} &=5.029 \\ \text { or } \qquad \qquad \qquad \qquad D &=2.94 \mathrm{~m} \end{aligned} \end{aligned}
Question 3
The depth of flow in an alluvial channel is 1.5 m. If critical velocity ratio is 1.1 and Manning's n is 0.018, the critical velocity of the channel as per Kenedy's method is
The critical velocity as per Kennedy's method is given by, \begin{aligned} V_{0} &=0.55 \mathrm{my}^{0.64}=0.55 \times 1.1 \times(1.5)^{0.64} \\ &=0.784 \mathrm{m} / \mathrm{s} \end{aligned}
Question 4
A stable channel is to be designed for a discharge of Q m^{3}/s with silt factor f as per Lacey's method. The mean flow velocity (m/s) in the channel is obtained by
As per Lacey's method of design of alluvial
channels, P=475 \sqrt{Q}
Question 6
A launching apron is to be designed at downstream of a weir for discharge intensity
of 6.5 m^{3}/s/m. For the design of launching aprons the scour depth is taken two times of Lacey scour depth. The silt factor of the bed material is unity. If the tailwater
depth is 4.4 m, the length of launching apron in the launched position is
On which of the canal systems, R.G. Kennedy, executive engineer in the the
Punjab Irrigation Department made his observations for proposing his theory on
stable channels ?