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

Transcription

1 CAB/2KTF/EET 1221/1413 Sixth Semester B. E. (R)/ First Semester B. E. (PTDP) Civil Engineering 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. Solve any one : (ii) What is hydrological equation? Describe briefly the components of this equation. The isohyetal weights of the stations in and around a river basin are 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 are inside. The rainfall records at these stations are 246, 281, 274, 252, 195, 321, 234 and 123 mm respectively. Determine the average depth of rainfall over the catchment by arithmetic and isohyetal mean methods. Solve any one : (ii) Estimate the daily evaporation from a large reservoir using following data: Water surface temp = 21 0 C, Air temperature = 29 0 C, Atmospheric pressure = 760 mm of Hg, Relative humidity = 50%, wind speed at lm above ground level = 28 km/hr Explain infiltratin capacity curve with the help of neat sketch Solve any one : CAB/2KTF/EET 1221/1413 Explain hydrograph with the help of a neat sketch. Also differentiate between flood hydragraph and unit hydrograph. Contd.

2 (ii) The ordinates of a 4 h unit hydrograph are given. Derive the ordinates of a 12 h unit hydrograph and plot the same Time (hr) Ordinate Solve any one : Explain rational method of flood estimation. (ii) What is the probality that a flood of certain magnitude with a return period of 20 years may occur in next 12 years? 3. Solve any five : Enlist the various forms of precipitation. (ii) (iii) Explain factors affecting evaporation. 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 : Derive an expression for a steady state discharge of a well fully penetrating into 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 pumped at a constant rate of 100 lit/min. The steady state draw down observed in two wells located at 10 m and 40 m distances from the centre of well are 3 m and 0.05 m respectively. Compute the hydraulic conductivity of the acquifer. 10 CAB/2KTF/EET 1221/ Contd.

3 5. Solve any two : Explain briefly about ground water quality. (ii) What do you understand by ground water recharge? Discuss different recharging methods. (iii) Discuss the criteria for fixing priority of water use in the region Solve any five : What are the methods for estimating design peak flood based on empirical formulae and probality theory. (ii) What is the difference between water table and perched water table? (iii) (iv) (v) (vi) Write a short note on River linking. Explain briefly about ground water quality. Distinguish between Aquifer and Aquiclude. Explain recharge through rain water harvesting. (vii) What is safe yield of an open well? 10 CAB/2KTF/EET 1221/

4 EAB/2KTF/SUT 1221/1413 Sixth Semester B. E. ( R ) / First Semester B. E. ( PTDP ) Civil Engineering Examination Course Code : CV 312 / CV 507 Course Name : Engineering Hydrology Time : 3 Hours ] [ Max. Marks : 60 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 Hydrological Cycle. 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 recorded by the gauges are as follows : Station Rainfall (mm) For a 10% error in the estimation of the mean rainfall, calculate the optimum number of stations in the catchment. Define raingauge. What are the different types of raingauges? Describe with a neat sketch the principle of working of "Tipping Bucket Type" recording raingauge (A) Define the term runoff and list the factors that affect the runoff of a given area. EAB/2KTF/SUT 1221/1413 Contd.

5 The ordinates of a unit hydrograph for a storm between 0 to 24 hours at every 4 hour duration are : Time (hr) Runoff (m 3 /s) Derive the ordinates of the 8 hr unit hydrograph for the basin by S curve method. 5 (B) Peak flow records for a river at a station, where a reservoir is to be constructed for a period of 80 years is as follows : The arithmetic mean of peaks = 7820 cumec. (ii) The standard deviation = 2500 m 3 /s. Using Gumbel's method, determine the recurrence interval for a flood of cumec. Explain Gumbel's method of estimation of flood discharge Write short on following (Any Five) : Importance of temperature in hydrological cycle. Practical Applications of Hydrology. Intensity duration frequency analysis. EAB/2KTF/SUT 1221/ Contd.

6 (d) Estimation of evaporation. (e) Factors affecting transpiration. (f) Base flow separation. (g) Flood forecasting Solve (Any Two) : Define the terms permeability, transmissibility, aquifer and specific yield. 5 A 24 cm well penetrates 32 m below the static ground water table. After a long period of pumping at a rate of 1.7 m/min, the drawdown in observation wells 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 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. What will be the discharge under a drawdown of 8 m? 5. Solve (Any Two) : (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 What are different methods of recharging? 5 Distinguish between water table and perched water table. 5 Write a short note on 'Recharge through Rain Water Harvesting' Write short notes (Any Five) : (d) (e) (f) Aquitard and Aquifuge. Criteria for selection of ground water recharge sites. Ground water quality. Multipurpose projects. Ground water movement. Water resources of India. (g) Watershed management. 10 EAB/2KTF/SUT 1221/

7 CKP/2K2FF/EQT 2064/2257 Sixth Semester B. E. / First B. E. PTDP Civil Engineering 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) 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. 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 recorded by the gauges are as follows : Station Rainfall (mm) For a 12% error in the estimation of the mean rainfall, calculate the optimum number of station in the catchment. Define raingauge. What are the different types of raingauges? Describe with a neat sketch the principle of working of ''Tipping Bucket Type'' recording rainguage (A) Explain briefly estimation of evaporation by using pans. CKP/2K2FF/EQT-2064/2257 Contd.

8 The ordinates of a unit hydrography for a storm between 0 to 24 hours at every 4 hour duration are : Time (hr) Runoff (m3/s) Derive the ordinates of the 8 hr unit hygrograph for the basin by S curve method. 5 (B) Peak flow records for a river at a station, where a reservoir is to be constructed for a period of 80 years is as follows : The arithmetic mean of peaks = 7820 comes. (ii) The standard deviation = 2500 m 3 /s. Using Gumbel's method, determine the recurrence interval for a flood of cumes. Explain Gumbel's method of estimation of flood discharge Write short on following (Any Five) : Importance of humidity in hydrological cycle. (d) Practical Applications of the subject. S Curve Hydrography. Estimation of evaporation. CKP/2K2FF/EQT-2064/ Contd.

9 (e) (f) Factors affecting evapotranspiration. Base flow separation. (g) Flood forecasting Methods Solve (Any Two) : Distinguish between pumping Test and Recuperation Test. A 24 cm well pentrates 30m below the static ground water table. After a long period of pumping at a rate of 1.7 m/min, the drawdown in observation wells 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 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. What will be the discharge under a drawdown of 8 m? (ii) What will be discharge in 40 cm well under a drawdoen of 4 m? assume radius of influence to remain 500 m in both the cases Solve (Any Two) : What do you understand by artificial method of recharging? 5 Distinguish between water table and perched water table. 5 What's is 'Recharge through Rain Water Harvesting', Explain in detail Write short notes (Any Five) : Aquifuge and Aquiclude. (d) (e) (f) Criteria for selection of ground water recharges sites. Specific yield and specific retention. Multipurpose projects. Confined and unconfined aquifer. River Linking. (g) Economic planning for flood control. 10 CKP/2K2FF/EQT-2064/

10 DAB/2KTF/ERT 1221/1413 Sixth Semester B. E. (R) / First Semester B. E. (PTDP) Civil Engineering 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 question carry marks as indicted. (3) Assume suitable data wherever necessary. (4) Illustrate your answers wherever necessary with the help of neat sketches. 1. Define rain gauge. What are the different types of rain gauges? Describe with neat sketch the working of "Tipping Bucket Type" recording rain gauge. 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 lie outside the basin while the remaining are inside. The rainfalls recorded at these stations are 123, 234, 321, 195, 252, 274, 281 and 246 respectively. Determine the average depth of rainfall over the catchment by arithmetic and isohyetal mean methods. 5 The following are the monthly pan evaporation data from January to December in a particular locality in cms : 15.2, 16.5, 18.4, 19.1, , 5,21.3, 17.2, 18.3, 20.1, 20.0, The water spread area in a lake nearby in the beginning of January and at the end of December are 3.5 km 2 and 3.2 km 2 respectively. Calculate the loss of water due to evaporation in that year. Assume pan coefficient as DAB/2KTF/ERT 1221/1413 Contd.

11 (d) The mean monthly temperatures in May and November are C and C respectively. Determine the potential evapotranspiration for sugarcane crop at this place for these two months. The crop coefficients for sugarcane is 0.9 in May and 0.85 in November. The monthly daylight hours as the percentage of daylight hours of the year are 8.96 for May and 7.56 for November The ordinates of surface ranoff of 4 hr duration from a catchment area of 357 km 2 are measured at 1 hr interval are given below. Determine the ordinates of 6 hr UH using S Curve technique. Time (Hours) Surface Runoff Ordinates (m 3 /s) Explain Khosla's method, define the parameters and determine runoff coefficient for the data given below. Month Jan Feb Mar April May Jun Jul Aug Sep Oct Nov Dec Temp( 0 C) Rain (cm) A 500 ha watershed has land use/cover and corresponding runoff coefficient as given below : Land use/cover Area(ha) Runoff Coefficient Forest Barren land Cultivated Land DAB/2KTF/ERT 1221/ Contd.

12 The maximum length of travel of water in watershed is about 3000 m and the elevation difference between the highest and outlet points of the watershed is 25 m. the maximum intensity duration frequency relationship of the watershed is given by : 6.311T i = (D+0.50) i = intensity in cm/hr; T = return period in years; estimate 25 year peak runoff from the watershed. 5 (d) The data on maximum annual flood indicates that maximum annual flood equal to or greater than 300 m 3 /sec has return period of 60 year. Find the probability of maximum annual flood j 300 m 3 /s : Once in 25 successive years and. (ii) Twice in 10 successive years Write short on following (any five) : (d) (e) (f) Methods of rainfall measurement. Factors affecting precipitation. Infiltration capacity curve. Factors affecting evaporation. Draw neat sketch of hydrograph. Draw neat sketch of ISI pan evaporimeter. (g) Explain Khosla's method Solve (any two) : Derive the equation for discharge from a confined aquifer. 5 DAB/2KTF/ERT 1221/ Contd.

13 During a recuperation test the water level in an open well was depressed by pumping by 2.2 m, and it is recuperated by an amount of 1.4 m in 65 minutes. Determine : Yield from a well of 2.8 m diameter under a depression head of 3.3 m. (ii) Diameter of well to yield 9 liters per second under a depression head of 2.2 m. 5 Define specific yield and specific retention. Show that their sum is equal to prorosity Solve (any two) : Explain rain water harvesting with the help of practical example. 5 What do you know about multipurpose projects? Discuss about the requirement of various objectives in a multipurpose project. 5 What are the criteria for selection of ground water recharge sites? Also, explain groundwater recharge and recharging methods Write short notes (any five) : Flood forecasting. (d) (e) (f) Advance application for hydrological modeling. Assumptions for Dupuit's equation. Economic planning for flood control. Ground water quality. River linking. (g) Interstate river disputes. 10 DAB/2KTF/ERT 1221/

14 DAB/2KTF/ERT 1221/1413 Sixth Semester B. E. (R) / First Semester B. E. (PTDP) Civil Engineering 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 question carry marks as indicted. (3) Assume suitable data wherever necessary. (4) Illustrate your answers wherever necessary with the help of neat sketches. 1. Define rain gauge. What are the different types of rain gauges? Describe with neat sketch the working of "Tipping Bucket Type" recording rain gauge. 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 lie outside the basin while the remaining are inside. The rainfalls recorded at these stations are 123, 234, 321, 195, 252, 274, 281 and 246 respectively. Determine the average depth of rainfall over the catchment by arithmetic and isohyetal mean methods. 5 The following are the monthly pan evaporation data from January to December in a particular locality in cms : 15.2, 16.5, 18.4, 19.1, , 5,21.3, 17.2, 18.3, 20.1, 20.0, The water spread area in a lake nearby in the beginning of January and at the end of December are 3.5 km 2 and 3.2 km 2 respectively. Calculate the loss of water due to evaporation in that year. Assume pan coefficient as DAB/2KTF/ERT 1221/1413 Contd.

15 (d) The mean monthly temperatures in May and November are C and C respectively. Determine the potential evapotranspiration for sugarcane crop at this place for these two months. The crop coefficients for sugarcane is 0.9 in May and 0.85 in November. The monthly daylight hours as the percentage of daylight hours of the year are 8.96 for May and 7.56 for November The ordinates of surface ranoff of 4 hr duration from a catchment area of 357 km 2 are measured at 1 hr interval are given below. Determine the ordinates of 6 hr UH using S Curve technique. Time (Hours) Surface Runoff Ordinates (m 3 /s) Explain Khosla's method, define the parameters and determine runoff coefficient for the data given below. Month Jan Feb Mar April May Jun Jul Aug Sep Oct Nov Dec Temp( 0 C) Rain (cm) A 500 ha watershed has land use/cover and corresponding runoff coefficient as given below : Land use/cover Area(ha) Runoff Coefficient Forest Barren land Cultivated Land DAB/2KTF/ERT 1221/ Contd.

16 The maximum length of travel of water in watershed is about 3000 m and the elevation difference between the highest and outlet points of the watershed is 25 m. the maximum intensity duration frequency relationship of the watershed is given by : 6.311T i = (D+0.50) i = intensity in cm/hr; T = return period in years; estimate 25 year peak runoff from the watershed. 5 (d) The data on maximum annual flood indicates that maximum annual flood equal to or greater than 300 m 3 /sec has return period of 60 year. Find the probability of maximum annual flood j 300 m 3 /s : Once in 25 successive years and. (ii) Twice in 10 successive years Write short on following (any five) : (d) (e) (f) Methods of rainfall measurement. Factors affecting precipitation. Infiltration capacity curve. Factors affecting evaporation. Draw neat sketch of hydrograph. Draw neat sketch of ISI pan evaporimeter. (g) Explain Khosla's method Solve (any two) : Derive the equation for discharge from a confined aquifer. 5 DAB/2KTF/ERT 1221/ Contd.

17 During a recuperation test the water level in an open well was depressed by pumping by 2.2 m, and it is recuperated by an amount of 1.4 m in 65 minutes. Determine : Yield from a well of 2.8 m diameter under a depression head of 3.3 m. (ii) Diameter of well to yield 9 liters per second under a depression head of 2.2 m. 5 Define specific yield and specific retention. Show that their sum is equal to prorosity Solve (any two) : Explain rain water harvesting with the help of practical example. 5 What do you know about multipurpose projects? Discuss about the requirement of various objectives in a multipurpose project. 5 What are the criteria for selection of ground water recharge sites? Also, explain groundwater recharge and recharging methods Write short notes (any five) : Flood forecasting. (d) (e) (f) Advance application for hydrological modeling. Assumptions for Dupuit's equation. Economic planning for flood control. Ground water quality. River linking. (g) Interstate river disputes. 10 DAB/2KTF/ERT 1221/

18 DKP/2K2FF/ERST 2064/2257 Sixth Semester B. E. / First B. E. (PTDP) Civil Engineering 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) 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 wherever possible. (B) A basin has the area in the form of a figure given below. Th six rain gauges 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 depth of rainfall over the basin by arithmetic mean and Thiessen's polygon method. (Each side = 12 km) 5 DKP/2K2FF/ERST 2064/2257 Contd.

19 (C) The mean monthly temperatures in degree at a place from January to December in 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, for the month of April and September using Thornthwaite method. The daily hours for these two months as percentage of daily hours of the year are 9.0 and 6.0 respectively. Assume the value of 'a' = 2.7. (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) (A) With help of a neat sketch explain the methods of base flow separation of a hydrograph. (B) The ordinates of a 4 h unit hygrograph are given; Derive the ordinates of a 12-h unit hydrograph and plot the same. Time (hr) (C) Ordinates of hr UH A culvert is proposed across a stream draining an area of 200 hectares. The catchment has a slope of and the length of travel of water 5 DKP/2K2FF/ERST 2064/ Contd.

20 is 1150m. Estimate the 25 years flood if the rainfall is given by 1000 T r 0.2 (t+20) 0.7 Where, I is in mm/hr, T r is in year and, t is in minutes. Assume runoff coefficient of (D) Explain Gumbel's method of estimation of flood discharge and also determine the probability of occurrence of a flood of certain magnitude with a return period of 20 years may occur in next 12 years Write short on following (any Five) : Site selection for rain gauge station. (d) (e) (f) Forms of precipitation. Infiltration indices. Measures to reduce evaporation. Factors affecting evapo-transpiration. Define Runoff. Explain factors affecting runoff. (g) Draw a sketch of automatic rain gauge station Solve any Two : Explain the Dupuit-Thiem's theory for an unconfined aquifer. In a certain alluvial basin of 80 km 2, 60 million m 3 of ground water was pumped in a year; and the GWT dropped by 4m during that year. Assuming no replenishment during the year, estimate the specific yield of the aquifer. If the specific retention is 10%, what is the porosity of aquifer? (ii) If the replenishment during the year is known to be 20 million m 3, what is the specific yield and porosity? DKP/2K2FF/ERST 2064/ Contd.

21 In an artesian aquifer of 8 m thick, a 10 cm diameter well is pumped at a constant rate of 100 lit/min. The steady state draw-down observed in two wells located at 10 m and 50 m distances from the centre of the well are 3 m and 0.05 m respectively. Computer the transmissibility and hydraulic conductivity of the aquifer Solve any two : What do you understand by artificial recharge of ground water? Explain in brief recharge wall method (Injection well method) of artificial recharge. Explain 'Recharge through Rain Water Harvesting' with the help of practical example. What do you know about multipurpose projects?disucss about the requirement of various objectives in a multipurpose project Write short notes (any Five) : Aquifer and Aquiclude. (d) (e) (f) Specific Retention and Transmissibility Coefficient. Assumptions for Dupuit's equation. Specific capacity Ground water movement. Water resources of India. (g) Watershed management. 10 DKP/2K2FF/ERST 2064/

22 DPK/2K2FS/OT 3636/3831 B. E. Sixth Semester / First Semester B. E. ( PTDP ) Civil Engineering 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) 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 (B) A basin has the area in the form of a figure given below. The six gauges located 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 rainfall over the basin by arithmetic mean and Thiessen's polygon method. (Each side = 10 km) 5 (C) The following are the monthly pan evaporation data from January to December in a particular locality in cms : 15.2, 16.5, 18.4, 19.1, , 5, 21.3, 17.2, 18.3, 20.1, 20.0, The water spread area in a lake nearby in the beginning of January and at the end of December are 3.5 km 2 and 3.2 km 2 respectively. Calculate the loss of water due to evaporation in that year. Assume pan coefficient as DPK/2K2FS/OT 3636/3831 Contd.

23 (D) The mean monthly temperatures in May and November are C and C respectively. Determine the potential evapotranspiration for sugarcane crop at this place for these two months. The crop coefficients for sugarcane is 0.9 in May and 0.85 in November. The monthly daylight hours as the percentage of daylight hours of the year are 8.96 for May and 7.56 for November (A) Explain hydrograph with the help of a neat sketch. Also differentiate between flood hydrograph and unit hydrograph. 5 (B) Ordinates of 4 hr unit hydrograph of a basin of area 300 km 2 measured at 1 hr interval are 7, 36, 64, 90, 105, 92, 80, 68, 57, 45, 32, 28, 24, 17, 14, 8, 6, 3, 1.5 m 3 / s respectively. Obtain the ordinates of 3 hr unit hydrograph for the basin using s curve technique. 5 (C) A bridge has a projected life of 100 years and is designed for 100 years flood Determine the risk of this design (ii) What will be the return period if the risk of flood to equal or exceed is 20%? 5 (D) Explain rational method considering following terms : Design Flood (ii) (iii) Time of concentration (Tc) Return period of flood frequency (T) Also determine the probability of occurrence of a flood of certain magnitude with a return period of 30 years may occur in next 15 years. 5 DPK/2K2FS/OT 3636/ Contd.

24 3. Write short on following (any five) : Methods of rainfall measurement. (d) (e) (f) Factors affecting precipitation. Infiltration capacity curve. Factors affecting evaporation. Draw neat sketch of hydrograph. Draw neat sketch of ISI pan evaporimeter. (g) Explain Khosla's method Solve any two : Derive the equation for discharge from a confined aquifer. 5 During a recuperation test the water level in an open well was depressed by pumping by 2.2 m, and it is recuperated by an amount of 1.4 m in 65 minutes. Determine : Yield from a well of 2.8 m diameter under a depression head of 3.3 m. (ii) Diameter of well to yield 9 liters per second under a depression head of 2.2 m. 5 Define specific yield and specific retention. Show that their sum is equal to porosity Solve (any two) : Explain briefly on watershed management, with the help of practical example. 5 Explain 'Interbasin water transfer' with the help of practical example. 5 Explain methods of ground water recharge. 5 DPK/2K2FS/OT 3636/ Contd.

25 6. Write short notes (any five) : Aquifer and Aquitard. (d) (e) (f) Advance application for hydrological modeling. Assumptions for Dupuit's equation. Economic planning for flood control. Ground water quality. Recharge through rain water harvesting. (g) Interstate river disputes. 10 DPK/2K2FS/OT 3636/

26 SPK/2K2FS/ET 3636/3831 B. E. Sixth Semester/First Semester B. E. (PTDP) Civil Engineering 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. (5) Use of non programmable calculator, Drawing instruments is permitted. 1. (A) Explain different forms and different types of precipitation with the help of neat sketch. 5 (B) (C) A basin has the area in the form of a regular Hexagon with each side of 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 rainfall respectively. One more rain gauge G located at the centre have rainfall of 80 mm. Compute the average depth of rainfall over the basin by arithmetic mean and Thiessen polygon methods. 5 The mean monthly temperatures in degree at a place from January to December in 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 the month of April and September using Thornthwaite method. The daily hours for these two months as percentage of daily hours of the year are 9.0 and 6.0 respectively. Assume the value of 'a' = SPK/2K2FS/ET 3636/3831 Contd.

27 (D) An infiltration capacity curve prepared for a catchment indicate initial infiltration rate of 2.5cm/hr and attains a constant value of 0.5 cm/s after 10 hours. Determine total loss due to infiltration in 10 hours taking Hortan's constant k = 0.5/hr (A) With help of a neat sketch explain the methods of base flow separation of a hydrograph. 5 (B) The ordinates of a 4 h unit hydrograph are given; Derive the ordinates of a 12 h unit hydrograph and plot the same. Time (hr) Ordinates of 4 hr UH (C) Explain different methods to determine the quantity of flood discharge. Also explain factors affecting floods and effects of floods. 5 (D) Explain Gumbel's method of estimation of flood discharge and also determine the probability of occurrence of a flood of certain magnitude with a return period of 30 years may occur in next 12 years Write short on following (Any Five) : Draw a neat sketch of rain gauge station. (d) (e) (f) Factors affecting Precipitation. Hyetograph Measures to reduce evaporation. Difference between Transpiration and Evaporation. Enlist the flood affected regions along with its main cause. (g) Draw S curve hydrograph. 10 SPK/2K2FS/ET 3636/ Contd.

28 4. Solve (Any Two) : Give assumption and derive Dupuit Thiem's theory for an unconfined aquifer. 5 In a certain alluvial basin of 80 km 2, 60 million m 3 of ground water was pumped in a year and the GWT dropped by 4 m during that year. Assume no replenishment during the year, estimate the specific yield of the aquifer. If the specific retention is 10%, what is the porosity of aquifer? (ii) If the replenishment during the year is known to be 20 million m 3, what is the specific yield and porosity? 5 A 20 cm well penetrates 25 m below the static ground water table. After a long period of pumping at a rate of /min, the drawdown in observation wells at 10 m and 30 m from the pumped well are 1.0 m and 0.4 m. Determine : Transmissibility of aquifer. (ii) The draw down in the pumped well assuming a radius of influence of 300 m Solve (Any Two) : What do you know about multipurpose projects? Discuss about the requirement of various objectives in a multipurpose project. 5 Explain ground water quality and pollution. 5 Explain 'Recharge through Rain Water Harvesting' with the help of design details Write short notes (Any Five) : Surface water pollution. Relation between specific capacity, specific retention and porosity. 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/

29 SPK/2K2FS/ET 3520 B. E. Fourth Semester Civil Engineering Examination Course Code : CV 1216 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) 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 : Define rain gauge. What are the different types of rain gauges? Describe with a neat sketch the principle of working of Tipping Bucket Type recording gauge. 7 The annual rainfall measured over a catchment having an existing rain gauge network of six rain gauge stations are as follows : Station Rainfall (mm) SPK/2K2FS/ET 3520 If the permissible limit of error in the estimation of rainfall is 10%, estimate the optimum number of rain gauge stations required to estimate the rainfall with the desired degree of accuracy. Also determine the additional number of rain gauge stations required to be installed in an existing catchment. 7 Contd.

30 2. Solve any One of following : What are the various factors affecting infiltration? Discuss the salient features of infiltration capacity curve with the help of neat sketch. Also, give significance of Infiltration capacity curve. 8 The water spread area in the lake at the beginning of January was 3.2 km 2 and at the end of December was 2.6 km 2. The monthly evaporation data in cm in a year from January to December in the vicinity of lake was 18.5, 15.9, 18.7, 25.8, 29.3, 23.2, 17.5, 18.0, 18.0, 22.3, 17.5 and Assuming pan coefficient of 0.7, calculate the loss of water due to evaporation in million m 3 in the year Solve any One of following : The average depth of rainfall over a basin for a period of 12 months from 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 corresponding months are 25, 26,25, 24, 22, 21, 15, 14, 13, 24, 29 and 29 0 C respectively. Determine the annual runoff from the basin using Khosla's formula. 7 The ordinates of 4 hour unit hydrograph of a basin of area 300km 2 measured at 1 hour intervals are 0 7, 36, 65, 90, 105, 92, 80, 68, 57, 45, 32, 28, 24, 17, 14, 8, 6, 4, m 3 /sec respectively. Obtain the ordinates of a 3 hour unit hydrograph for the basin using the S curve technique. (Note : First value and last values are 0m 3 /sec) if [0, 7, 36, , 3, 1.5, 0] 7 4. Solve any One of following : The data on maximum annual flood indicates that the maximum annual flood equals to or greater than 250 m 3 /sec has return period of 50 years. Estimate the probability of maximum annual flood greater than or equal to 250 m 3 /sec. (1) Once in 20 successive years. (2) Twice in 10 successive years. 8 SPK/2K2FS/ET Contd.

31 A culvert is proposed across a stream draining an area of 185 hectares. The catchment has a slope of and the length of travel of water is 1150 m. Estimate the 25 years flood if the rainfall is given by [ T 0.2 i = mm, t c = min (t c + 20) 0.70 hr [ 8 5. Solve any Three of following : Derive an expression for a steady state discharge of a well, fully penetrating into a confined aquifer. 5 A 35 cm well in an unconfined aquifer of saturated thickness of 50 m yields 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 45 cm well under a drawdown of 4 m? Assume radius of influence to remain 500 m in both cases. 5 A 200 mm diameter well penetrates 40 m below ground water level. After a long period of pumping at a rate of 18 m 3 /min, the draw downs in the observation wells at 14 m and 40 m from the pumped well are 1.2 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 Attempt Any Three of following : What do you know about multipurpose projects? Discuss about the requirements of various objectives in a multipurpose project. 5 What do you understand by inter basi water transfer? Do you think it is really needed to meet the future water resources system? 5 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

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