Redd

1. A water course commands an irrigated area 100 hectares.
the intensity of
irrigation rice in this area is 70%.the transplantation of rice crop takes 15 days and
during transplantation period total depth of water required by the crop on the field
is 500mm.during the transplantation period, the useful rain falling on the field is
120mm.find the duty of irrigation water for crop on the field during transplantation
at the head of the field of the water course assuming loss of water to be 20% in the
water course. Also calculate the discharge required in water course.
2. A one day rain fall of 15cm at a place X was found to have a return period of 100
years. calculate the probability that one day rainfall of this or larger magnitude.
A) Will not occur at X during next 50 years,
b) Will occur 3 times in next 50 years.
6.Following velocities were recorded in a stream with a current meter.

Depth above bed (m): 0
Velocity (m/sec):
2
0.5
3
0.7
4
0.8
0.8
Find the discharge per unit width of the stream near the point of measurement.
Depth of flow at the point is 5 meter.
9. The following are the data obtained in a stream gauging operation. A current
meter with a calibration equation V=0.32N+0.032m/s, where N=revolutions per
second was used to measure the velocity at 0.6 depth. Using the mid-section
methods, calculate the discharge in the stream.
Distance
from the
right
bank(m)
12
15
18
20
22
23
24
Depth(m)
0.5
1.1
80
83
1.8
5
121
1.7
5
114
1.6
5
109
92
1.2
5
85
0.7
5
70
2.2
5
139
1.5
Number of
revolutions
Observatio
n time(s)
1.9
5
131
180
120
120
120
120
120
120
120
120
150
13. The isohyets for annual rainfall over a catchment basin were drawn. The areas
of strips between the isohyets are indicated below in table. Find the average depth
of annual precipitation over the basin.
Isohyets (cm)
75-85
85-95
95-105
105-115
115-135
135-155
Area in square kilometer

580
2960
2850
1000
610
160
14. Calculate the design discharge of canal at 0, 1, 2 and 3 km from headwork.

The gross commanded area at the head of canal is 60000 hectares and after each
km it is reduced by 10000 hectors. Of this command, the cultivated area is only
75%. The intensity of irrigation for Ravi and Kharif season is 35% and 18%
respectively. Assume total losses below 3 km=0.5 cumec. Channel losses per km =
3% of discharge at the beginning of each km, kor period Ravi(wheat) and
Kharif(rice) is 4 and 2.5 weeks respectively. Kor depth for Ravi and Kharif is 14 and
20 cm respectively.
15. a.)
Design an irrigation canal in clayey alluvial soil for full supply

discharge=3.5 cumecs , coefficient of roughness 0.025, canal side slope 1:1 and
longitudinal slope 1 in 5000. Also check for critical velocity ratio, allowable CVR is
0.9 to 1.1.
b).
Design the above canal by Laceys theory.
18.
What is the evaporation if 4.2 litre of water is removed from an evaporation

pan of diameter 1.22 m and simultaneous rainfall measurement is 8.75mm?
19. From a double ring infiltrometre the following

infiltration rates were observed.
Time 0.016 0.058 0.125 0.25
in
7
3
hours
F in
8.76
7.9
6.45
4.68
cm/h
0.50
0.75
1.25
2.75
1.76
1.10
Determine the constants fo, fc, and k of the Hortons

equation to describe the above data.
20. The catchment area of a basin is in the shape of a regular hexagon of side
40km.7 rain gauges located one at each end of the hexagon and one of at each
end of the hexagon and one of the centre records precipitation of
10,20,30,40,50,60,70 respectively.using Thiesen polygon method, compute the
average precipitation over the basin.
21.Determine Q-index for a basin of 500km^2.the direct run off of a flood was 5cm
and equivalent uniform rainfall depth over the catchment was 15cm.the time
distribution of rainfall was as under:
Time(hr)
Rainfall(cm)
5-6
2
6-7
3
7-8
6
8-9
4
9-10
1
24.A 6 hour storm produced rainfall intensities of 7,18,25,12,10,3 mm/h in

successive 1 hour intervals over a basin of 800 sq km.The resulting run off is
observed to be 2640 hectr-metres.determine Q-index for the basin.
26.Rice requires 30cm of water during the period September 1st to 15 th.What is the
duty? Express it also in terms of ha per million cubic meters.
27.Table below furnishes the kind of crop irrigated from the water of a reservoir4
by means of the canal system. The data about these crops are also furnished in the
table.
Kind of crop
Crop- period in
days
Area under crops in

ha
Cotton
Sugarcane
Wheat
Rice
240
365
120
120
3000
2000
4000
2000
Duty of water in
the field in
ha/cumec
1430
860
2150
860
Assume 30% losses of water in the entire canal system and 15% losses in the
reservoir. Find the live storage of in the reservoir in ha/m.
29.On a catchment area of 200 sq km,rainfalls of 7.5cm,2cm,5cm occurred on

three consecutive days.the Q-index was 205cm/day.the distribution graph
percentages of surface runoff which extended over six days for every rainfall of
such magnitudes are 5,15,40,25,10,5.determine the ordinates of the discharge
hydrograph and determine the peak discharge .neglect the base flow.
30. Calculate the value of Q-index from the following data of storm of 8cm
precipitation that resulted in a direct run off of 4.4cm.
Time in
hrs
Increment
al rainfall
per he in
cm
0.57
0.58
1.25
1.4
1.2

Redd

Uploaded by

Copyright:

Available Formats

Redd

Uploaded by

Document Information

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Redd

Uploaded by

Copyright:

Available Formats

1. A water course commands an irrigated area 100 hectares.

6.Following velocities were recorded in a stream with a current meter.

Area in square kilometer

14. Calculate the design discharge of canal at 0, 1, 2 and 3 km from headwork.

Design an irrigation canal in clayey alluvial soil for full supply

Design the above canal by Laceys theory.

What is the evaporation if 4.2 litre of water is removed from an evaporation

19. From a double ring infiltrometre the following

Determine the constants fo, fc, and k of the Hortons

24.A 6 hour storm produced rainfall intensities of 7,18,25,12,10,3 mm/h in

Area under crops in

29.On a catchment area of 200 sq km,rainfalls of 7.5cm,2cm,5cm occurred on

You might also like