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Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Fifth semester B.Tech degree examinations (S) September 2020

Course Code: CE309
Course Name: WATER RESOURCES ENGINEERING

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer any two full questions, each question carries 15 marks. Marks
1 a) Explain the method of determination of optimum number of raingauges in a catchment (4)

b) Compare Thiessen polygon method and isohyetal method for determination of average (6)
precipitation over a catchment

c) Explain rainfall mass curve and hyetograph. How will you construct a hyetograph from (5)
rainfall mass curve

2 a) A trapezoidal channel of bed width 4 m and side slope 1 : 1 carries water ata depth of 2 (5)
m. The rate of evaporation observed was 0.35 mm/m7/h. Find 11९ daily loss due to
evaporation from the canal in a length of 10 km in ha m.

b) Explain the factors affecting runoff from a catchment (10)

3 8) Enlist the uses and limitations of unit hydrograph theory (5)

b) Given below are the ordinates of 4 hr UH of a basin. Derive 2 hr UH of the basin using (10)
S-curve method

Time

(hrs)

UHO 0 | 20 | 36 | 60 | 80 | 112 | 120 | 105 | 92 | 40 | 24 | 14 இ 7 1/0

(m*/sec)
PART B
Answer any two full questions, each question carries 15 marks.
4 a) Define Duty and Delta. Obtain the relation between the two (5)

0) A canal was designed to supply the irrigation needs of 1000 ha of land growing rice of 120 (10)
days base period and having a delta of 130 cm. Instead of rice if the canal water is used
entirely to irrigate wheat of base period 118 days and having delta of 50 cm, determine the
area that can be irrigated by the canal supplies.

5 9) Explain irrigation efficiencies. (5)

b) Explain benefits and ill effects of irrigation. (4)

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