R10Set No: 1
Code No: R31014
III B.Tech. I Semester Regular and Supplementary Examinations, December-2013
WATER RESOURCES ENGINEERING-I
(Civil Engineering)
Time: 3 HoursMax Marks: 75
Answer any FIVE Questions
All Questions carry equal marks
**
1.(a) Define Hydrologic cycle with a neat sketch. Discuss the various process and
storages involved in the system.
(b) For a drainage basin of 500 km2, isohyetals drawn for a storm gave the following
data:
Isohyetal Interval (cm)
Area bounded between
isohytes (km2)
0-33-66-99-1212-15
7515012513090
Estimate the average depth of precipitation over the catchment.
2.(a) What is the difference between Ф-index and w-index? How is Ф index determined
from the rainfall hyetograph?
(b) Write down the most common empirical formula used to calculate evaporation.
3.(a) What is a unit hydrograph? List the assumptions involved in the unit hydrograph
theory. What are the uses of unit hydrograph?
(b) The direct runoff hydrograph resulting from a 4.5 cm of effective rainfall of 6 hr duration is given below. Determine the area of the catchment and the ordinates of the 6 hr unit hydrograph.
Time (hr)061218243036424854606672
Direct
runoff0501503003503102251501005030100
(m3/sec)
4.(a) What is meant by stream gauging? Describe the velocity area method that is used
for stream gauging.
(b) Describe the Muskingum method of routing an inflow hydrograph through a channel reach.
5. (a) Briefly explain the following terms: (i) Radius of influence (ii) Water table
(iii) Partially penetrating well (iv) Transmissibility.
(b) Calculate the discharge in m3/day from a tube well under the following conditions of an unconfined aquifer: Diameter of the well = 50 cm; Drawdown at the well = 10 m; length of strains = 25 m; radius of influence of the well = 250 m; coefficient of permeability = 0.01 cm/s.
6. (a) What are the benefits that can be accured from irrigation projects?
(b) Discuss the quality standards required for irrigation water.
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R10Set No: 1
Code No: R31014
7.(a) What is meant by Duty and Delta of canal water? Derive the relationship between
them for a given base period.
(b) Compute the depth and frequency of irrigation required for a certain crop with data given below: root zone depth = 100 cm; field capacity = 22%; wilting point = 12%; apparent specific gravity of soil = 1.5; consumptive use = 25mm/day; efficiency of irrigation = 50%; Assume 50% depletion on available moisture before application of irrigation water at field capacity.
8.(a) Explain the necessity of lining of canal. Enumerate the various types of linings
practiced in India.
(b) Design an irrigation channel section for the following data: discharge = 30 cumecs; silt factor = 1.0; side slopes = ½ : 1, Determine the longitudinal slope also.
**
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R10Set No: 2
Code No: R31014
III B.Tech. I Semester Regular and Supplementary Examinations, December-2013
WATER RESOURCES ENGINEERING-I
(Civil Engineering)
Time: 3 HoursMax Marks: 75
Answer any FIVE Questions
All Questions carry equal marks
**
1. (a) Explain the different methods of determining the average rainfall over a catchment
due to a storm. Discuss the relative merits and demerits of the various methods.
(b) What is an intensity duration curve? Write down the general expression for intensity duration relationship of rainfall. Explain the necessity for frequency analysis.
2. (a) What do you understand by the term infiltration? How can you measure it in the field?
(b) A storm with 10 cm precipitation produced a direct runoff of 5.8 cm. The time distribution of the storm as given below, estimate the Ф-index of the storm.
Time from start (hr)12345678
Increments/ Rainfall
in each hour (cm)
0.40.91.52.31.81.61.00.5
3.(a) Draw a unit hydrograph and explain the sailent features. What is synthetic unit
hydrograph?
(b) The ordinates of a2hr unit hydrograph are given below. Determine the ordinates of an 3 hr. unit hydrograph using S - Curve technique.
Time (hr)0246810121416182022
12-h UH
ordinates0209015020017510070302060
(m3/sec)
4.(a) Enumerate the different methods which are used for stream gauging. Discuss any one
of these methods in details.
(b) What are the basic equations used for flood routing by (i) Hydrologic method and (ii) Hydraulic method.
5. (a) Write assumptions of Dupuit’s equation. Derive the basic differential equation for
steady ground water flow in a well fully penetration into a confined aquifer.
(b) During a recuperation test, the water in an open well was depressed, by pumping by
2.5 m and it recuperated 1.8 m in 80 minutes. Find (a) yield from a well of 4 m diameter under a depression head of 3 m, (ii) the diameter of the well to yield 8 lit/sec under a depression head of 2 meters.
6.(a) Write short notes on:(i) drip irrigation method(ii) mixed cropping (iii) flood
irrigation.
(b) What are the ill effects of Irrigation? Discuss its usefulness for irrigating fine textured
soils.
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R10Set No: 2
Code No: R31014
7. (a) Explain the following terms:
(i) Field capacity (ii) Paleo irrigation (iii) Available moisture (iv) Crop rotation.
(b) Name any two methods used for estimating consumptive use of water.
8. (a) Write short notes on: (i) balancing depth (ii) canal lining (iii) classification of canals.
(b) Design an earth canal section to carry 50 cumecs discharge at a slope of 0.25 m/km, N= 0.0225, m = 1.0.
**
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R10Set No: 3
Code No: R31014
III B.Tech. I Semester Regular and Supplementary Examinations, December-2013
WATER RESOURCES ENGINEERING-I
(Civil Engineering)
Time: 3 HoursMax Marks: 75
Answer any FIVE Questions
All Questions carry equal marks
**
1.(a) Define Hydrologic cycle with a neat sketch. Discuss the various process and storages
involved in the system.
(b) Explain briefly the following relationships relating to the precipitation over a basin.
(i) Depth- Area relationship;(ii) Depth-Area-Duration curves and(iii) Intensity-
Duration frequency curves.
2.(a) What is evaporation? Mention the factors controlling the evaporation process.
(b) A watershed of 50 km2 produces a runoff of 2 Mm3 from the rainfall pattern of the
storm given below, Calculate Ф-index.
Time (hr)02468101212
Rainfall (mm)01.12.26.05.03.01.00
3.(a) What is meant by runoff and how is it produced? Discuss briefly the various factors
on which it depends.
(b) Describe the method of computing the ordinates of a unit-hydrograph from the data of a flood hydrograph.
4. (a) Enumerate the different methods of measuring discharge.
(b) Describe the Muskingum flood routing .
5. (a) Briefly explain the following terms: (i) specific yield (ii) aquifer and aquitard (iii)
Darcy’s law (iv) storage coefficient of an aquifer.
(b) A 25 cm well penetrates 50 m below the static water table. After a long period of pumping at a rate of 1000 lpm, the drawdown in the wells 20 m and 40 m from the pumped well is found to be 4 m and 2.5 m respectively. Determine the transmissibility of the aquifer. What is the drawdown in the pumped well?
6.(a) What is meant by surface and subsurface irrigation and what are their types? Discuss
briefly.
(b) How is the flow irrigation different from the lift irrigation?
7.(a) Write short notes on: (i) consumptive use of water (ii) water distribution efficiency
(iii) crop seasons in India.
(b) What are the factors on which duty depends? How can the duty be improved?
8.(a) Describe briefly the two recognized silt theories. Explain how one theory is an
improvement over the other.
(b) Design a trapezoidal concrete lined channel to carry a discharge of 350 cumecs at a slope of 1 in 6400. The side slopes of the channel may be taken as 1 ½: 1. The value of n for lining material may be taken as 0.013. Assume B/D = 5.
**
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R10Set No: 4
Code No: R31014
III B.Tech. I Semester Regular and Supplementary Examinations, December-2013
WATER RESOURCES ENGINEERING-I
(Civil Engineering)
Time: 3 HoursMax Marks: 75
Answer any FIVE Questions
All Questions carry equal marks
**
1. (a) Differentiate between recording and Non-recording types of rain gauges.
(b) The annual rainfalls at seven raingauge stations in a basin are 55, 95, 60, 45, 20, 80, and 65 cm respectively. What is the percentage accuracy of the existing network in the estimation of the average depth of rainfall over the basin? How many additional gauges are required if it is desired to limit the error to only 10%?
2.(a) Discuss the use of pan measurements for the determination of evaporation from water
surface.
(b) A 6 hr storm produced rainfall intensities of 7, 18, 25, 12, 10, and 3 mm/h in successive one hour intervals over a basin of 800 km2. The resulting runoff is observed to be 2640 hectare meters. Determine Ф-index for the basin.
3. (a) What is S-curve hydrograph? How is it constructed, and what is it used for?
(b) Derive the ordinates of 1 hr unit hydrograph for the drainage basin of 1329 km2 catchment using the 3 hr unit hydrograph ordinates.
Time (hr)0123456789101112131415
Ordinates
of 3 hr54
unit016577505804653522621951439760331570
hydrograp
h
4. (a) Distinguish between hydraulic and hydrologic method of flood routing.
(b) What are the various methods of estimating the design flood of a catchment?
5. (a) What do you understand by recuperation test? Derive the equations used in the test.
(b) A 30 cm diameter well penetrates 20 m below the static water table. After 24 hours of
pumping at 5000 lit/min, the water level in a test well at 100 m away is lowered by 0.5 m
and in a well at away, the drawdown is 1 m. What is the transmissibility of the aquifer?
6.(a) Write short notes on:(i) ill-effects of irrigation(ii) crop rotation(iii) salt
concentrations of irrigation water.
(b) What is flood irrigation? Where is it practiced?
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R10Set No: 4
Code No: R31014
7.(a) Write short notes on: (i) frequency of irrigation (ii) irrigation efficiencies (iii) field
irrigation requirement.
(b) After how many days will you supply water to soil in order to ensure sufficient
irrigation of the given crop, if: field capacity of the soil = 28%; permanent wilting point =
13%; dry density of soil = 1.3 gm/cc; effective depth of root zone = 70 cm; daily
consumptive use of water for the given crop = 12 mm. Assume any other data required.
8.(a) Write short notes on: (i) Balancing depth (ii) Economics of canal lining
(iii) Advantages of canal lining.
(b) Design an irrigation channel section for the following data: discharge = 40 cumecs; silt factor = 1.0; side slopes = ½ : 1. Determine the longitudinal slope also.
**
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