Question Paper: Hydrology & Water Resources Engineering : Question Paper May 2015 - Civil Engineering (Semester 5) | Gujarat Technological University (GTU)
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## Hydrology & Water Resources Engineering - May 2015

### Civil Engineering (Semester 5)

TOTAL MARKS:
TOTAL TIME: HOURS

1 (a) Differentiate between low and high head power plants. Discuss components of a hydroelectric power plant(7 marks) 1 (b) With a neat sketch, describe various zones of storage in a reservoir. Also suggest measures to control reservoir sedimentation(7 marks) 2 (a) What is the need for planning of water resources projects? Discuss the steps involved in the water resources planning.(7 marks) 2 (b) Discuss causes of drought and drought contingency planning.(7 marks) 2 (c) What is meant by 'water harvesting'? Explain methods of roof water harvesting and water harvesting for agricultural use.(7 marks) 3 (a) i) Explain various forms of precipitation.(3 marks) 3 (a) ii) Explain the use of tipping bucket type rain gauge.(4 marks) 3 (b) The rates of rainfall for successive 30 minute period of a 3-hour storm are 1.5, 3.2, 4.3, 2.7, 2.1 and 1.2 cm/hr. The surface runoff in response to the storm is estimated to be 3.0 cm. Determine ϕ-index and w-index. Consider a total of depression and interception losses of 1.0 cm.(7 marks) 3 (c) i) A rain gauge 'D' was inoperative during a specific storm. The rainfall recorded at three surrounding stations A, B and C during that storm were 52, 85 and 70 mm respectively. If the average annual rainfall of stations A, B, C and D are 650, 900, 820 and 700 mm respectively, estimate the storm rainfall of station D.(3 marks) 3 (c) ii) The rainfall values at gauging stations and corresponding areas of Thiessen's polygons for a drainage basin are as follows:

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 Station A B C D E F G Area of Thiessen's Polygon (km2) 160 135 92 110 68 70 35 Rainfall (cm) 10.0 13.5 9.1 12.6 11.2 14.0 10.8

Compute the average rainfall over the basin.(4 marks) 3 (d) What are the factors that affect Evaporation? Describe any one method of measurement of evaporation.(7 marks) 4 (a) Explain procedure to derive s-curve hydrograph from a given unit hydrograph. What are the uses of s-curve hydrograph?(7 marks) 4 (b) Discuss occurrence of groundwater with a neat sketch and define various water bearing formations.(7 marks) 4 (c) Define Hydrograph. Draw a typical single-peaked hydrograph and explain its components.(7 marks) 4 (d) The ordinates of flood hydrograph for a drainage basin in response to a 6- hour storm are observed as follows:
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 Time (hour) 0 3 6 9 12 15 18 21 Hydrograph Ordinate (cumec) 15 35 67 109 151 175 195 153

<colgroup span="9" style="text-align: center;" width="85"> </colgroup>
 Time (hour) 24 27 30 33 36 39 42 45 Hydrograph Ordinate (cumec) 139 113 87 63 47 31 23 15

Considering total rainfall of 7 cm during the storm, average rate of infiltration loss of 0.5 cm/hr and a constant base flow of 15 cumec, derive ordinates of the 6-hour unit hydrograph. Also estimate area of the basin.
(7 marks)
5 (a) Discuss causes of flood.(7 marks) 5 (b) Explain flood routing through reservoirs.(7 marks) 5 (c) Write a short note on flood control by constructing levees and flood walls.(7 marks) 5 (d) Briefly explain method of estimating design flood for a water resources Project.(7 marks)