Question Paper: Irrigation Engineering Question Paper - May 18 - Civil Engineering (Semester 7) - Mumbai University (MU)
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Irrigation Engineering - May 18

Civil Engineering (Semester 7)

Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question No. 1 is compulsory
(2) Solve any three out of remaining questions
(3) Draw neat diagrams wherever necessary

Q1) Answer any four out of the following

1(a) Discuss in brief various methods of surface irrigation. (5 marks)

1(b) Define Duty, Delta and Base period. Derive the relationship between them. (5 marks)

1(c) What is hydrograph? Draw a single peaked hydrograph and explain its components. (5 marks)

1(d) Explain the terms 'storage coefficient' and 'coefficient of permeability'. (5 marks)

1(e) What are the factors on which the selection of site of reservoir depends? (5 marks)

1(f) Give the detail classification of Dams. (5 marks)

2(a) After how many days will you supply water to soil in order to ensure efficient irrigation of the given crop, if
(i) Field capacity of soil = 27%
(ii) Permanent wilting point = 14%
(iii) Dry density of soil = $15 kN/m^3$
(iv) Effective depth of root zone = 75cm (v) Daily consumptive use of water for the given crop = 11mm
(7 marks)

2(b) The CCA of area of watercourse is 1200 ha. Intensities of sugarcane and wheat crops are 20% and 40% respectively. The duties for the crops at the head of the water course are 730 ha/cumecs and 1800 ha/cumecs respectively. Calculate the Discharge at the water course. (7 marks)

2(c) What is the importance of duty? Explain the variation of duty with the place of its measurement. (6 marks)

3(a) Discuss the various method of computing average rainfall over a basin. (8 marks)

3(b) A catchment has five rain gauge stations. In a year, the annual rainfalls recorded by the gauges are 78.8 cm, 90.2 cm, 98.6 cm, 102.4 cm, and 70.4 cm. For a 6% error in the estimation of the mean rainfall, determine the additional number of gauges needed. (4 marks)

3(c) Using the 3 hr unit hydrograph given below, find the peak flow, resulting from our successive 3 hr periods of rainfall producing 0.35, 0.87, 1.39, and 0.77 cm of runoff respectively from a basin.

Time (hr) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Flow ($m^3/s$) 0 16 58 173 337 440 400 285 215 165 122 90 60 35 16 0

Neglect base flow. (8 marks)

4(a) Derive an expression for discharge from a well fully penetrating an unconfined acquifer. (7 marks)

4(b) During a recuperation test, the water in an open well was depressed by pumping by 2.5 m and it is recuperated 1.8m in 80 minutes. Find
(a) yield from a well of 4m diameter under a depression head of 3 meters,
(b) the diameter of well to yield 8 lit/sec under a depression head of 2m.
(5 marks)

4(c) What is reservoir sedimentation? What are the methods to control it. (8 marks)

5(a) Write a short note on storage zones of reservoir and control levels (6 marks)

5(b) What are the modes of failure of gravity dam? (7 marks)

5(c) Write a short note on practical profile of gravity dam. (7 marks)

6(a) What are the causes of failure of earthen dam. (10 marks)

6(b) Write a short note on following.
1. Cross Drainage works.
2. Arch dam and Buttress Dam.
(10 marks)