CAB/2KTF/EET 1221/1413 Sixth Semester B. E. (R)/ First ... · PDF fileof this equation. (ii) ... Using Gumbel's method, ... First Semester B. E. (PTDP) Civil Engineering Examination

CAB/2KTF/EET – 1221/1413

Sixth Semester B. E. (R)/ First Semester B. E. (PTDP) CivilEngineering Examination

Course Code : CV 312 / CV 507 Course Name : Engineering Hydrology

Time : 3 Hours ] [ Max. Marks : 60

Instructions to Candidates :—(1) All questions are compulsory.(2) All questions carry marks as indicated.(3) Assume suitable data wherever necessary.(4) Illustrate your answers wherever necessary with the help of neat sketches.

1. (a) Solve any one :––

(i) What is hydrological equation ? Describe briefly the componentsof this equation.

(ii) The isohyetal weights of the stations in and around a river basinare 0.06, 0.10, 0.05, 0.25, 0.08, 0.12, 0.04 and 0.3 respectively.Stations 3, 5, 7 lie outside the basin while the remaining areinside. The rainfall records at these stations are 246, 281, 274,252, 195, 321, 234 and 123 mm respectively. Determine theaverage depth of rainfall over the catchment by arithmetic andisohyetal mean methods.

(b) Solve any one :––

(i) Estimate the daily evaporation from a large reservoir using followingdata: Water surface temp = 210

C, Air temperature = 290 C, Atmospheric

pressure = 760 mm of Hg, Relative humidity = 50%, wind speed atlm above ground level = 28 km/hr

(ii) Explain infiltratin capacity curve with the help of neat sketch.5

2. (a) Solve any one :––

(i) Explain hydrograph with the help of a neat sketch. Also differentiatebetween flood hydragraph and unit hydrograph.

CAB/2KTF/EET –1221/1413 Contd.

(ii) The ordinates of a 4–h unit hydrograph are given. Derive theordinates of a 12–h unit hydrograph and plot the same

Time (hr) 0 4 8 12 16 20 24 28 32 36 40 44

Ordinate 0 20 80 130 150 130 90 52 27 15 5 0

5

(b) Solve any one :––

(i) Explain rational method of flood estimation.

(ii) What is the probality that a flood of certain magnitude witha return period of 20 years may occur in next 12 years ?

3. Solve any five :––

(i) Enlist the various forms of precipitation.

(ii) Explain factors affecting evaporation.

(iii) Explain the method of base flow separation of a hydrograph.

(iv) What do you mean by design flood and time of concentration ?

(v) Explain hydrological cycle.

(vi) Explai factors affecting transpiration and evapo transpiration. 10

(vii) Explain interception and its measurement.

4. Solve any two :––

(i) Derive an expression for a steady state discharge of a well fully penetratinginto a confined acquifer

(ii) Define specific yield and specific retention. What is their relation with porosity ?

(iii) In an artesian acquifer of 8 m thick, a 10 cm diameter well is pumpedat a constant rate of 100 lit/min. The steady state draw down observedin two wells located at 10 m and 40 m distances from the centre ofwell are 3 m and 0.05 m respectively. Compute the hydraulic conductivityof the acquifer. 10

CAB/2KTF/EET –1221/1413 2 Contd.


(i) Explain briefly about ground water quality.

(ii) What do you understand by ground water recharge ? Discuss different rechargingmethods.

(iii) Discuss the criteria for fixing priority of water use in the region.10

6. Solve any five :––

(i) What are the methods for estimating design peak flood based on empiricalformulae and probality theory.

(ii) What is the difference between water table and perched water table ?

(iii) Write a short note on River linking.

(iv) Explain briefly about ground water quality.

(v) Distinguish between Aquifer and Aquiclude.

(vi) Explain recharge through rain water harvesting.

(vii) What is safe yield of an open well ? 10

CAB/2KTF/EET –1221/1413 3 205

EAB/2KTF/SUT – 1221/1413

Sixth Semester B. E. ( R ) / First Semester B. E. ( PTDP ) CivilEngineering Examination



Instructions to Candidates :—(1) All questions carry marks as indicated.(2) Due credit will be given to neatness and adequate dimensions.(3) Assume suitable data wherever necessary.(4) Illustrate your answers wherever necessary with the help of neat sketches.(5) Use of non programmable calculator, Drawing instruments is permitted.

1. (A) Explain with neat sketch, Horton's engineering representation of HydrologicalCycle.

OR

Briefly explain the optimum number of rain gauge stations in a catchment.5

(B) A catchment has six raingauge stations. In a year the annual rainfall recordedby the gauges are as follows :

Station 1 2 3 4 5 6

Rainfall (mm) 826 1029 1803 1103 988 1367

For a 10% error in the estimation of the mean rainfall, calculate the optimumnumber of stations in the catchment.

OR

Define raingauge. What are the different types of raingauges ? Describewith a neat sketch the principle of working of "Tipping Bucket Type" recordingraingauge. 5

2. (A) Define the term runoff and list the factors that affect the runoff of agiven area.

EAB/2KTF/SUT–1221/1413 Contd.

OR

The ordinates of a unit hydrograph for a storm between 0 to 24 hoursat every 4 hour duration are :

RunoffTime (hr) (m3/s)

0 0

4 1500

8 1200

12 600

16 220

20 80

24 0

Derive the ordinates of the 8 hr unit hydrograph for the basin by Scurve method. 5

(B) Peak flow records for a river at a station, where a reservoir is to beconstructed for a period of 80 years is as follows :

(i) The arithmetic mean of peaks = 7820 cumec.

(ii) The standard deviation = 2500 m3/s.

Using Gumbel's method, determine the recurrence interval for a flood of15000 cumec.

OR

Explain Gumbel's method of estimation of flood discharge. 5

3. Write short on following (Any Five) :—

(a) Importance of temperature in hydrological cycle.

(b) Practical Applications of Hydrology.

(c) Intensity duration frequency analysis.

EAB/2KTF/SUT–1221/1413 2 Contd.

(d) Estimation of evaporation.

(e) Factors affecting transpiration.

(f) Base flow separation.

(g) Flood forecasting. 10

4. Solve (Any Two) :—

(a) Define the terms permeability, transmissibility, aquifer and specific yield. 5

(b) A 24 cm well penetrates 32 m below the static ground water table. Aftera long period of pumping at a rate of 1.7 m/min, the drawdown in observationwells at 12 m and 36 m from the pumped well are 1.1 m and 0.4 m.determine Transmissibility of aquifer. Take radius of influence of 300 m.

5(c) A 38 cm well in an unconfined aquifer of saturated thickness of 60 m yields

1200 lpm under a drawdown of 4 m at a pumping well.

(i) What will be the discharge under a drawdown of 8 m ?

(j) What will be discharge in 40 cm well under a drawdown of 4 m ?Assume radius of influence to remain 500 m in both the cases.

5


(a) What are different methods of recharging ? 5

(b) Distinguish between water table and perched water table. 5

(c) Write a short note on 'Recharge through Rain Water Harvesting'. 5

6. Write short notes (Any Five) :—

(a) Aquitard and Aquifuge.

(b) Criteria for selection of ground water recharge sites.

(c) Ground water quality.

(d) Multipurpose projects.

(e) Ground water movement.

(f) Water resources of India.

(g) Watershed management. 10

EAB/2KTF/SUT–1221/1413 3 55

CKP/2K2FF/EQT – 2064/2257

Sixth Semester B. E. / First B. E. PTDP Civil EngineeringExamination

Course Code : CV 312/CV 507 Course Name : Engineering Hydrology


Instructions to Candidates :—(1) All questions are compulsory.

(2) All questions carry marks as indicated.

(3) Due credit will be given to neatness and adequate dimensions.

(4) Assume suitable data wherever necessary.

(5) Illustrate your answers wherever necessary with the help of neat sketches.

1. (A) Explain in detail with neat sketch, Hydrological Cycle.

OR

Explain the necessity of optimum number of rain gauge stations in a catchment.5

(B) A catchment has six raingauge stations. In a year the annual rainfall recordedby the gauges are as follows :

Station 1 2 3 4 5 6

Rainfall (mm) 830 1029 1803 1103 988 1367

For a 12% error in the estimation of the mean rainfall, calculate the optimumnumber of station in the catchment.

OR

Define raingauge. What are the different types of raingauges ? Describewith a neat sketch the principle of working of ''Tipping Bucket Type'' recordingrainguage. 5

2. (A) Explain briefly estimation of evaporation by using pans.

CKP/2K2FF/EQT-2064/2257 Contd.

OR

The ordinates of a unit hydrography for a storm between 0 to 24 hoursat every 4 hour duration are :

Time (hr) Runoff (m3/s)

0 0

4 1530

8 1250

12 700

16 250

20 70

24 0

Derive the ordinates of the 8 hr unit hygrograph for the basin by S curvemethod. 5

(B) Peak flow records for a river at a station, where a reservoir is to beconstructed for a period of 80 years is as follows :

(i) The arithmetic mean of peaks = 7820 comes.

(ii) The standard deviation = 2500 m3/s.

Using Gumbel's method, determine the recurrence interval for a flood of15000 cumes.

OR

Explain Gumbel's method of estimation of flood discharge. 5

3. Write short on following (Any Five) :––

(a) Importance of humidity in hydrological cycle.

(b) Practical Applications of the subject.

(c) S Curve Hydrography.

(d) Estimation of evaporation.

CKP/2K2FF/EQT-2064/2257 2 Contd.

(e) Factors affecting evapotranspiration.

(f) Base flow separation.

(g) Flood forecasting Methods. 10

4. Solve (Any Two) :––

(a) Distinguish between pumping Test and Recuperation Test.

(b) A 24 cm well pentrates 30m below the static ground water table. Aftera long period of pumping at a rate of 1.7 m/min, the drawdown in observationwells at 10m and 34 m from the pumped well are 1.1 m and 0.4 m.determine Transmissibility of aquifer. Take radius of influence of 320 m.

5

(c) A 38 cm well in an unconfined aquifer of saturated thickness of 60 myields 1200 lpm under a drawdown of 4 m at a pumping well.

(i) What will be the discharge under a drawdown of 8 m ?

(ii) What will be discharge in 40 cm well under a drawdoen of4 m ? assume radius of influence to remain 500 m in both thecases. 5

5. Solve (Any Two) :––

(a) What do you understand by artificial method of recharging ? 5

(b) Distinguish between water table and perched water table. 5

(c) What's is 'Recharge through Rain Water Harvesting', Explain in detail.5

6. Write short notes (Any Five) :––

(a) Aquifuge and Aquiclude.

(b) Criteria for selection of ground water recharges sites.

(c) Specific yield and specific retention.

(d) Multipurpose projects.

(e) Confined and unconfined aquifer.

(f) River Linking.

(g) Economic planning for flood control. 10

CKP/2K2FF/EQT-2064/2257 3 175

DAB/2KTF/ER T – 1221/1413

Sixth Semester B. E. (R) / First Semester B. E. (PTDP) CivilEngineering Examination



Instructions to Candidates :—(1) All questions are compulsory.(2) All question carry marks as indicted.(3) Assume suitable data wherever necessary.(4) Illustrate your answers wherever necessary with the help of neat sketches.

1. (a) Define rain gauge. What are the different types of rain gauges ? Describewith neat sketch the working of "Tipping Bucket Type" recording rain gauge.

OR

(b) The isohyetal weights of the stations in and around a river basin are 0.30,0.04, 0.12, 0.08, 0.25, 0.05, 0.10, 0.06 respectively. Station 3, 5, 7 lieoutside the basin while the remaining are inside. The rainfalls recorded atthese stations are 123, 234, 321, 195, 252, 274, 281 and 246 respectively.Determine the average depth of rainfall over the catchment by arithmeticand isohyetal mean methods. 5

(c) The following are the monthly pan evaporation data from January to Decemberin a particular locality in cms : 15.2, 16.5, 18.4, 19.1, 22.524, 5,21.3,17.2, 18.3, 20.1, 20.0, 14.3. The water spread area in a lake nearbyin the beginning of January and at the end of December are 3.5 km2

and 3.2 km2 respectively. Calculate the loss of water due to evaporationin that year. Assume pan coefficient as 0.72.

DAB/2KTF/ER T–1221/1413 Contd.

OR

(d) The mean monthly temperatures in May and November are 27.50C and22.50C respectively. Determine the potential evapotranspiration for sugarcanecrop at this place for these two months. The crop coefficients for sugarcaneis 0.9 in May and 0.85 in November. The monthly daylight hours asthe percentage of daylight hours of the year are 8.96 for May and 7.56for November. 5

2. (a) The ordinates of surface ranoff of 4–hr duration from a catchment areaof 357 km2 are measured at 1 hr interval are given below. Determinethe ordinates of 6–hr UH using S–Curve technique.

Time (Hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Surface Runoff0 15 25 36 38 48 69 91 113 101 88 71 54 31 21 9

Ordinates (m3/s)

OR

(b) Explain Khosla's method, define the parameters and determine runoff coefficientfor the data given below.

Month Jan Feb Mar April May Jun Jul Aug Sep Oct Nov Dec

Temp(0C) 12 16 21 27 31 34 31 29 28 29 19 14

Rain (cm) 4 4 2 0 2 12 32 29 16 2 1 2

5

(c) A 500 ha watershed has land use/cover and corresponding runoff coefficientas given below :

Land use/cover Area(ha) Runoff Coefficient

Forest 250 0.10

Barren land 50 0.11

Cultivated Land 200 0.30

DAB/2KTF/ER T–1221/1413 2 Contd.

The maximum length of travel of water in watershed is about 3000 mand the elevation difference between the highest and outlet points of thewatershed is 25 m. the maximum intensity duration frequency relationshipof the watershed is given by : 6.311T0.1523 i = ——————— (D+0.50)0.945

i = intensity in cm/hr; T = return period in years; estimate 25 year peakrunoff from the watershed. 5

OR

(d) The data on maximum annual flood indicates that maximum annual floodequal to or greater than 300 m3/sec has return period of 60 year. Findthe probability of maximum annual flood j 300 m3/s :

(i) Once in 25 successive years and.

(ii) Twice in 10 successive years. 5

3. Write short on following (any five) :—

(a) Methods of rainfall measurement.

(b) Factors affecting precipitation.

(c) Infiltration capacity curve.

(d) Factors affecting evaporation.

(e) Draw neat sketch of hydrograph.

(f) Draw neat sketch of ISI pan evaporimeter.

(g) Explain Khosla's method. 10

4. Solve (any two) :—

(a) Derive the equation for discharge from a confined aquifer. 5


(b) During a recuperation test the water level in an open well was depressedby pumping by 2.2 m, and it is recuperated by an amount of 1.4 min 65 minutes.

Determine :—

(i) Yield from a well of 2.8 m diameter under a depression headof 3.3 m.

(ii) Diameter of well to yield 9 liters per second under a depressionhead of 2.2 m. 5

(c) Define specific yield and specific retention. Show that their sum is equalto prorosity. 5


(a) Explain rain water harvesting with the help of practical example. 5

(b) What do you know about multipurpose projects ? Discuss about the requirementof various objectives in a multipurpose project. 5

(c) What are the criteria for selection of ground water recharge sites ? Also,explain groundwater recharge and recharging methods. 5

6. Write short notes (any five) :—

(a) Flood forecasting.

(b) Advance application for hydrological modeling.

(c) Assumptions for Dupuit's equation.

(d) Economic planning for flood control.

(e) Ground water quality.

(f) River linking.

(g) Interstate river disputes. 10

DAB/2KTF/ER T–1221/1413 4 105

DAB/2KTF/ER T – 1221/1413

Sixth Semester B. E. (R) / First Semester B. E. (PTDP) CivilEngineering Examination



Instructions to Candidates :—(1) All questions are compulsory.(2) All question carry marks as indicted.(3) Assume suitable data wherever necessary.(4) Illustrate your answers wherever necessary with the help of neat sketches.

1. (a) Define rain gauge. What are the different types of rain gauges ? Describewith neat sketch the working of "Tipping Bucket Type" recording rain gauge.

OR

(b) The isohyetal weights of the stations in and around a river basin are 0.30,0.04, 0.12, 0.08, 0.25, 0.05, 0.10, 0.06 respectively. Station 3, 5, 7 lieoutside the basin while the remaining are inside. The rainfalls recorded atthese stations are 123, 234, 321, 195, 252, 274, 281 and 246 respectively.Determine the average depth of rainfall over the catchment by arithmeticand isohyetal mean methods. 5

(c) The following are the monthly pan evaporation data from January to Decemberin a particular locality in cms : 15.2, 16.5, 18.4, 19.1, 22.524, 5,21.3,17.2, 18.3, 20.1, 20.0, 14.3. The water spread area in a lake nearbyin the beginning of January and at the end of December are 3.5 km2

and 3.2 km2 respectively. Calculate the loss of water due to evaporationin that year. Assume pan coefficient as 0.72.

DAB/2KTF/ER T–1221/1413 Contd.

OR

(d) The mean monthly temperatures in May and November are 27.50C and22.50C respectively. Determine the potential evapotranspiration for sugarcanecrop at this place for these two months. The crop coefficients for sugarcaneis 0.9 in May and 0.85 in November. The monthly daylight hours asthe percentage of daylight hours of the year are 8.96 for May and 7.56for November. 5

2. (a) The ordinates of surface ranoff of 4–hr duration from a catchment areaof 357 km2 are measured at 1 hr interval are given below. Determinethe ordinates of 6–hr UH using S–Curve technique.

Time (Hours) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Surface Runoff0 15 25 36 38 48 69 91 113 101 88 71 54 31 21 9

Ordinates (m3/s)

OR

(b) Explain Khosla's method, define the parameters and determine runoff coefficientfor the data given below.

Month Jan Feb Mar April May Jun Jul Aug Sep Oct Nov Dec

Temp(0C) 12 16 21 27 31 34 31 29 28 29 19 14

Rain (cm) 4 4 2 0 2 12 32 29 16 2 1 2

5

(c) A 500 ha watershed has land use/cover and corresponding runoff coefficientas given below :

Land use/cover Area(ha) Runoff Coefficient

Forest 250 0.10

Barren land 50 0.11

Cultivated Land 200 0.30


The maximum length of travel of water in watershed is about 3000 mand the elevation difference between the highest and outlet points of thewatershed is 25 m. the maximum intensity duration frequency relationshipof the watershed is given by : 6.311T0.1523 i = ——————— (D+0.50)0.945

i = intensity in cm/hr; T = return period in years; estimate 25 year peakrunoff from the watershed. 5

OR

(d) The data on maximum annual flood indicates that maximum annual floodequal to or greater than 300 m3/sec has return period of 60 year. Findthe probability of maximum annual flood j 300 m3/s :

(i) Once in 25 successive years and.

(ii) Twice in 10 successive years. 5












(b) During a recuperation test the water level in an open well was depressedby pumping by 2.2 m, and it is recuperated by an amount of 1.4 min 65 minutes.

Determine :—



(c) Define specific yield and specific retention. Show that their sum is equalto prorosity. 5


(a) Explain rain water harvesting with the help of practical example. 5

(b) What do you know about multipurpose projects ? Discuss about the requirementof various objectives in a multipurpose project. 5

(c) What are the criteria for selection of ground water recharge sites ? Also,explain groundwater recharge and recharging methods. 5


(a) Flood forecasting.





(f) River linking.


DAB/2KTF/ER T–1221/1413 4 105

DKP/2K2FF/ERST – 2064/2257

Sixth Semester B. E. / First B. E. (PTDP) Civil EngineeringExamination

Course Code : CV 312/ CV 507 Course Name : Engineering Hydrology


Instructions to Candidates :—(1) All questions are compulsory.(2) All questions carry marks as indicated.(3) Due credit will be given to neatness and adequate dimensions.(4) Assume suitable data wherever necessary.(5) Illustrate your answers wherever necessary with the help of neat sketches.

1. (A) Explain different types of precipitation with the help of neat sketch whereverpossible.

OR

(B) A basin has the area in the form of a figure given below. Th six raingauges located at A, B, C, D, E and F have recorded 60, 81, 70,55, 65 and 45 mm of rainfall respectively. Compute the average depthof rainfall over the basin by arithmetic mean and Thiessen's polygon method.(Each side = 12 km)

5

DKP/2K2FF/ERST–2064/2257 Contd.

(C) The mean monthly temperatures in degree at a place from January to Decemberin a year are 16.6, 18.6, 23.3, 27.6, 25.0, 24.4, 23.7, 23.4, 23.6, 19.0,18.3, and 15.4 respectively. Compute the potential evapo–transpiration, forthe month of April and September using Thornthwaite method. The dailyhours for these two months as percentage of daily hours of the year are9.0 and 6.0 respectively. Assume the value of 'a' = 2.7.

OR

(D) Determine the net runoff, total rainfall and w-index for the following data:Φ-index = 3.0 cm/hr.

Time of rainfall Rate of Rainfall (cm/hr)

20 2.5

20 3.5

20 11.0

20 7.5

20 4.5

20 5.5 5

2. (A) With help of a neat sketch explain the methods of base flow separationof a hydrograph.

OR

(B) The ordinates of a 4–h unit hygrograph are given; Derive the ordinatesof a 12-h unit hydrograph and plot the same.

Time (hr) 0 4 8 12 16 20 24 28 32 36 40 44

Ordinates of 0 20 80 130 150 130 90 52 27 15 5 04-hr UH

5

(C) A culvert is proposed across a stream draining an area of 200 hectares.The catchment has a slope of 0.005 and the length of travel of water

DKP/2K2FF/ERST–2064/2257 2 Contd.

is 1150m. Estimate the 25 years flood if the rainfall is given by

1000 Tr0.2

––––––––– (t+20)0.7

Where,I is in mm/hr, Tr is in year and, t is in minutes. Assume runoff coefficientof 0.33.

OR

(D) Explain Gumbel's method of estimation of flood discharge and also determinethe probability of occurrence of a flood of certain magnitude with a returnperiod of 20 years may occur in next 12 years. 5

3. Write short on following (any Five) :––

(a) Site selection for rain gauge station.

(b) Forms of precipitation.

(c) Infiltration indices.

(d) Measures to reduce evaporation.

(e) Factors affecting evapo-transpiration.

(f) Define Runoff. Explain factors affecting runoff.

(g) Draw a sketch of automatic rain gauge station. 10

4. Solve any Two :––

(a) Explain the Dupuit-Thiem's theory for an unconfined aquifer.

(b) In a certain alluvial basin of 80 km2, 60 million m3 of ground water waspumped in a year; and the GWT dropped by 4m during that year.

(i) Assuming no replenishment during the year, estimate the specificyield of the aquifer. If the specific retention is 10%, what isthe porosity of aquifer ?

(ii) If the replenishment during the year is known to be 20 millionm3, what is the specific yield and porosity ?

DKP/2K2FF/ERST–2064/2257 3 Contd.

(c) In an artesian aquifer of 8 m thick, a 10 cm diameter well is pumpedat a constant rate of 100 lit/min. The steady state draw-down observedin two wells located at 10 m and 50 m distances from the centre of thewell are 3 m and 0.05 m respectively. Computer the transmissibility and hydraulicconductivity of the aquifer. 10


(a) What do you understand by artificial recharge of ground water ? Explainin brief recharge wall method (Injection well method) of artificial recharge.

(b) Explain 'Recharge through Rain Water Harvesting' with the help of practicalexample.

(c) What do you know about multipurpose projects ?Disucss about the requirementof various objectives in a multipurpose project. 10

6. Write short notes (any Five) :––

(a) Aquifer and Aquiclude.

(b) Specific Retention and Transmissibility Coefficient.


(d) Specific capacity

(e) Ground water movement.

(f) Water resources of India.

(g) Watershed management. 10

DKP/2K2FF/ERST–2064/2257 4 25

DPK/2K2FS/OT– 3636/3831

B. E. Sixth Semester / First Semester B. E. ( PTDP ) Civil EngineeringExamination



Instructions to Candidates :—(1) All questions are compulsory.(2) All questions carry marks as indicated.(3) Due credit will be given to neatness and adequate dimensions.(4) Assume suitable data wherever necessary.(5) Illustrate your answers wherever necessary with the help of neat sketches.

1. (A) Explain hydrological cycle with the help of neat sketch. 5

OR

(B) A basin has the area in the form of a figure given below. The six gaugeslocated at A , B , C , D , E , F and G have recorded 60 , 81 , 70 , 55 , 65 ,45 and 50 mm of rainfall respectively. Compute the average depth of rainfallover the basin by arithmetic mean and Thiessen's polygon method. (Eachside = 10 km)

5

(C) The following are the monthly pan evaporation data from January to Decemberin a particular locality in cms : 15.2 , 16.5 , 18.4 , 19.1 , 22.524 , 5 , 21.3 ,17.2 , 18.3 , 20.1 , 20.0 , 14.3. The water spread area in a lake nearby inthe beginning of January and at the end of December are 3.5 km2 and

3.2 km2 respectively. Calculate the loss of water due to evaporation in thatyear. Assume pan coefficient as 0.72. 5

DPK/2K2FS/OT – 3636/3831 Contd.

OR

(D) The mean monthly temperatures in May and November are 27.5 0C and

22.5 0C respectively. Determine the potential evapotranspiration for sugarcane

crop at this place for these two months. The crop coefficients for sugarcaneis 0.9 in May and 0.85 in November. The monthly daylight hours asthe percentage of daylight hours of the year are 8.96 for May and 7.56for November. 5

2. (A) Explain hydrograph with the help of a neat sketch. Also differentiate betweenflood hydrograph and unit hydrograph. 5

OR

(B) Ordinates of 4 – hr unit hydrograph of a basin of area 300 km2 measuredat 1 hr interval are 7 , 36 , 64 , 90 , 105 , 92 , 80 , 68 , 57 , 45 , 32 , 28 , 24 ,17 , 14 , 8 , 6 , 3 , 1.5 m3

/ s respectively. Obtain the ordinates of 3 hr unit hydrographfor the basin using s – curve technique. 5

(C) A bridge has a projected life of 100 years and is designed for 100years flood

(i) Determine the risk of this design

(ii) What will be the return period if the risk of flood to equalor exceed is 20% ? 5

OR

(D) Explain rational method considering following terms :—

(i) Design Flood

(ii) Time of concentration (Tc)

(iii) Return period of flood frequency (T)

Also determine the probability of occurrence of a flood of certain magnitudewith a return period of 30 years may occur in next 15 years.5

DPK/2K2FS/OT – 3636/3831 2 Contd.









4. Solve any two :—


(b) During a recuperation test the water level in an open well was depressedby pumping by 2.2 m, and it is recuperated by an amount of 1.4 min 65 minutes. Determine :—



(c) Define specific yield and specific retention. Show that their sum is equalto porosity. 5


(a) Explain briefly on watershed management, with the help of practical example.5

(b) Explain 'Interbasin water transfer' with the help of practical example.5

(c) Explain methods of ground water recharge. 5

DPK/2K2FS/OT – 3636/3831 3 Contd.

DPK/2K2FS/OT – 3636/3831 4 15


(a) Aquifer and Aquitard.





(f) Recharge through rain water harvesting.


SPK/2K2FS/ET – 3636/3831

B. E. Sixth Semester/First Semester B. E. (PTDP) Civil EngineeringExamination



Instructions to Candidates :—

(1) All questions are compulsory.

(2) All questions carry marks as indicated.

(3) Assume suitable data wherever necessary.

(4) Illustrate your answers wherever necessary with the help of neat sketches.(5) Use of non–programmable calculator, Drawing instruments is permitted.

1. (A) Explain different forms and different types of precipitation with the help ofneat sketch. 5

OR

(B) A basin has the area in the form of a regular Hexagon with each sideof length 15 km. The six rain gauges located at the corners A, B, C,D, E and F have recorded 50, 55, 60, 65, 70 and 75 mm of rainfallrespectively. One more rain gauge G located at the centre have rainfallof 80 mm. Compute the average depth of rainfall over the basin by arithmeticmean and Thiessen polygon methods. 5

(C) The mean monthly temperatures in degree at a place from January to Decemberin a year are 16.6, 18.6, 23.3, 27.6, 25.0, 24.4, 23.7, 23.4, 23.6, 19.0,18.3 and 15.4 respectively. Compute the potential evapotranspiration for themonth of April and September using Thornthwaite method. The daily hoursfor these two months as percentage of daily hours of the year are 9.0and 6.0 respectively. Assume the value of 'a' = 2.7. 5

SPK/2K2FS/ET–3636/3831 Contd.

OR

(D) An infiltration capacity curve prepared for a catchment indicate initial infiltrationrate of 2.5 cm/hr and attains a constant value of 0.5 cm/s after 10hours. Determine total loss due to infiltration in 10 hours taking Hortan'sconstant k = 0.5/hr. 5

2. (A) With help of a neat sketch explain the methods of base flow separationof a hydrograph. 5

OR

(B) The ordinates of a 4–h unit hydrograph are given; Derive the ordinatesof a 12–h unit hydrograph and plot the same.

Time (hr) 0 4 8 12 16 20 24 28 32 36 40 44

Ordinates of 4–hr UH 0 20 80 130 150 130 90 52 27 15 5 0

5

(C) Explain different methods to determine the quantity of flood discharge. Alsoexplain factors affecting floods and effects of floods. 5

OR

(D) Explain Gumbel's method of estimation of flood discharge and also determinethe probability of occurrence of a flood of certain magnitude with a returnperiod of 30 years may occur in next 12 years. 5

3. Write short on following (Any Five) :—(a) Draw a neat sketch of rain gauge station.

(b) Factors affecting Precipitation.

(c) Hyetograph

(d) Measures to reduce evaporation.

(e) Difference between Transpiration and Evaporation.

(f) Enlist the flood affected regions along with its main cause.

(g) Draw S–curve hydrograph. 10

SPK/2K2FS/ET–3636/3831 2 Contd.


(a) Give assumption and derive Dupuit–Thiem's theory for an unconfined aquifer.5

(b) In a certain alluvial basin of 80 km2, 60 million m3 of ground waterwas pumped in a year and the GWT dropped by 4 m during that year.

(i) Assume no replenishment during the year, estimate the specificyield of the aquifer. If the specific retention is 10%, what isthe porosity of aquifer ?

(ii) If the replenishment during the year is known to be 20 millionm3, what is the specific yield and porosity ? 5

(c) A 20 cm well penetrates 25 m below the static ground water table. Aftera long period of pumping at a rate of 1800 1/min, the drawdown in observationwells at 10 m and 30 m from the pumped well are 1.0 m and 0.4m. Determine :—

(i) Transmissibility of aquifer.

(ii) The draw down in the pumped well assuming a radius of influenceof 300 m. 5

5. Solve (Any Two) :—(a) What do you know about multipurpose projects ? Discuss about the requirement

of various objectives in a multipurpose project. 5

(b) Explain ground water quality and pollution. 5

(c) Explain 'Recharge through Rain Water Harvesting' with the help of designdetails. 5

6. Write short notes (Any Five) :—(a) Surface water pollution.

(b) Relation between specific capacity, specific retention and porosity.

(c) Types of floods.

(d) Ground water movement.

(e) Watershed management.

(f) Recuperation test.

(g) Differentiate between confined and unconfined aquifers. 10

SPK/2K2FS/ET–3636/3831 3 225

SPK/2K2FS/ET – 3520

B. E. Fourth Semester Civil Engineering Examination

Course Code : CV 1216 Course Name : Engineering Hydrology


Instructions to Candidates :—(1) All questions are compulsory.(2) All questions carry marks as indicated.(3) Due credit will be given to neatness and adequate dimensions.(4) Assume suitable data wherever necessary.(5) Illustrate your answers wherever necessary with the help of neat sketches.(6) Use of non programmable calculator Drawing instruments is permitted.

1. Solve any One of following :—(a) Define rain gauge. What are the different types of rain gauges ? Describe

with a neat sketch the principle of working of Tipping Bucket Type recordinggauge. 7

OR

(b) The annual rainfall measured over a catchment having an existing rain gaugenetwork of six rain gauge stations are as follows :—

Station Rainfall(mm)

1 826

2 1029

3 1803

4 1103

5 988

6 1367

If the permissible limit of error in the estimation of rainfall is 10%, estimatethe optimum number of rain gauge stations required to estimate the rainfallwith the desired degree of accuracy. Also determine the additional numberof rain gauge stations required to be installed in an existing catchment.

7

SPK/2K2FS/ET–3520 Contd.

2. Solve any One of following :—

(a) What are the various factors affecting infiltration ? Discuss the salient featuresof infiltration capacity curve with the help of neat sketch. Also, give significanceof Infiltration capacity curve. 8

OR

(b) The water spread area in the lake at the beginning of January was3.2 km2 and at the end of December was 2.6 km2. The monthly evaporationdata in cm in a year from January to December in the vicinity of lakewas 18.5, 15.9, 18.7, 25.8, 29.3, 23.2, 17.5, 18.0, 18.0, 22.3, 17.5and 17.2. Assuming pan coefficient of 0.7, calculate the loss of water dueto evaporation in million m3 in the year. 8


(a) The average depth of rainfall over a basin for a period of 12 monthsfrom June to May are 90, 250, 230, 130, 50, 200, 15, 26, 30, 14,0 and 2 mm respectively. The mean monthly temperatures in the correspondingmonths are 25, 26,25, 24, 22, 21, 15, 14, 13, 24, 29 and 290C respectively.Determine the annual runoff from the basin using Khosla's formula.7

OR

(b) The ordinates of 4 hour unit hydrograph of a basin of area 300 km2

measured at 1 hour intervals are 07, 36, 65, 90, 105, 92, 80, 68, 57,

45, 32, 28, 24, 17, 14, 8, 6, 4, 3 1.50m

3/sec respectively. Obtain

the ordinates of a 3 hour unit hydrograph for the basin using the S curvetechnique.

(Note : First value and last values are 0m3/sec)

if [0, 7, 36, 65 ..... 4, 3, 1.5, 0] 7


(a) The data on maximum annual flood indicates that the maximum annualflood equals to or greater than 250 m3/sec has return period of 50 years.Estimate the probability of maximum annual flood greater than or equalto 250 m3/sec.(1) Once in 20 successive years.(2) Twice in 10 successive years. 8

SPK/2K2FS/ET–3520 2 Contd.

OR

(b) A culvert is proposed across a stream draining an area of 185 hectares.The catchment has a slope of 0.004 and the length of travel of wateris 1150 m. Estimate the 25 years flood if the rainfall is given by

10000T0.2 mm i = ––––––––––– –––– , tc = min (tc + 20)0.70 hr 8

5. Solve any Three of following :—

(a) Derive an expression for a steady state discharge of a well, fully penetratinginto a confined aquifer. 5

(b) A 35 cm well in an unconfined aquifer of saturated thickness of 50 myields 1000 lpm under a drawdown of 4 m at a pumping well.

5

(1) What will be the discharge under a drawdown of 8 m ?

(2) What will be discharge in 45cm well under a drawdown of4 m ?

Assume radius of influence to remain 500 m in both cases. 5

(c) A 200 mm diameter well penetrates 40 m below ground water level. Aftera long period of pumping at a rate of 18 m3/min, the draw downs inthe observation wells at 14 m and 40 m from the pumped well are1.2 m and 0.6 m respectively. Determine the transmissibility of the aquifer.Take radius of influence as 320 m. 5

(d) Distinguish between pumping test and recuperation test. 5

6. Attempt Any Thr ee of following :—

(a) What do you know about multipurpose projects ? Discuss about the requirementsof various objectives in a multipurpose project. 5

(b) What do you understand by inter–basi water transfer ? Do you think itis really needed to meet the future water resources system ? 5

(c) Explain ground water recharge through Rain water Harvesting. 5

(d) Write in detail the criteria for selecting the site for ground water recharge.5

[[

SPK/2K2FS/ET–3520 3 255

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CAB/2KTF/EET 1221/1413 Sixth Semester B. E. (R)/ First ... · PDF fileof this equation. (ii) ... Using Gumbel's method, ... First Semester B. E. (PTDP) Civil Engineering Examination