Hydrology and Irrigation Engineering 2018 Question Paper — Government…
The 2018 Hydrology and Irrigation Engineering previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.
- University: Government College of Engineering and Technology, Jammu
- Subject: Hydrology and Irrigation Engineering
- Course: Engineering Hydrology
- Branch: CIVIL ENGINEERING
- Year: 2018
- Paper: end-term
- Duration: 180 minutes
- Total marks: 100
Instructions
- Attempt any Five questions selecting atleast One question from each Unit.
- All questions carry equal marks. Assume missing data, if any, suitably.
Questions
UNIT - I
- Q1. a) Describe with neat sketch the construction and use of a float-type of a recording gauge. (12) b) The infiltration capacity of a soil in small water shed was found to be $6\text{ cm/hr}$ before a rainfall event. It was found to be $1.2\text{ cm/hr}$ at the end of $8\text{hr}$ of storm. If the total infiltration during the $8\text{hr}$ period of storm was $15\text{cm}$, Estimate the value of the decay coefficient $\text{K}_\text{h}$ in horton's infiltration capacity equation. (8) [20 marks]
- Q2. a) Explain Thiessen's method for calculating average depth of precipitation over an area with a neat sketch. (10) b) A storm with a $15\text{cm}$ precipitation produced a direct runoff of $8.7\text{cm}$. The time distribution of the storm is as follows: | Time from start (in hr) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |---|---|---|---|---|---|---|---|---| | Incremental rain fall in each hr. (in cm) | 0.6 | 1.35 | 2.25 | 3.45 | 2.7 | 2.4 | 1.5 | 0.75 | Estimate the $\phi_{\text{index}}$ of the storm (10) [20 marks]
UNIT - II
- Q3. a) Why is base flow separated from the flood hydrograph in the process of developing a unit hydrograph. (8) b) Given below are the ordinates of a unit hydrograph, derived from a storm on a $1329\text{ sq km}$ catchment, and believed to have resulted from a rain of $3\text{ hour}$ unit duration. (12) | Hour | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---| | Runoff $\text{m}^3$ | 0 | 165 | 547 | 750 | 580 | 465 | 352 | 262 | 195 | 143 | 97 | 60 | 33 | 15 | 7 | 0 | Determine the unit hydrograph of $1\text{ hour}$ unit duration by S-curve hydrograph. [20 marks]
- Q4. The coordinates of instantaneous unit hydrograph (IUH) of a catchment are given below. Derive the direct runoff hydrograph (DRH) for this catchment due to a storm of duration $4\text{ hours}$ and having a rainfall excess of $5\text{cm}$. (20) | Time (hours) | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |---|---|---|---|---|---|---|---|---|---|---|---|---|---| | IUH ordinates u(t) $(\text{m}^3\text{/s})$ | 0 | 8 | 35 | 50 | 47 | 40 | 31 | 23 | 15 | 10 | 6 | 3 | 0 | [20 marks]
UNIT - III
- Q5. a) What are the various methods of estimating the design flood of a catchment? (10) b) A bridge has an expected life of $25\text{ years}$ and is design for a flood magnitude of return period $100\text{ years}$ (a) what is the risk of this hydrological design. (b) If a $10\text{%}$ risk is acceptable, what return period will have to be adopted? (10) [20 marks]
- Q6. a) For a river the estimated flood peaks for two return periods by using Gumbel's method are given below: | Return period (years) | Peak flood $(\text{m}^3\text{/s})$ | |---|---| | 100 | 485 | | 50 | 445 | What flood discharge in this river will have a return period of $1000\text{ years}$? (10) b) Describe briefly the various methods for obtaining the maximum flood discharge of a river. (10) [20 marks]
UNIT - IV
- Q7. a) Explain the following: (12) i) Aquifer. ii) Capillary fringe. iii) Perched Water table. b) Find out the Velocities of the ground water flow with the following data, using Slichter and Hazen's constants as $400$ & $800$ respectively. Viscosity coefficient of water at ground water temperature of $10^\circ\text{C} = 1$. Effective size of particles in the aquifer $= 0.1\text{mm}$, hydraulic gradient $1\text{ in } 80$. (8) [20 marks]
- Q8. What is meant by tube wells? Explain their types with neat sketches and what are the approximate values of the average yield and depth of widely used tube wells. (20) [20 marks]