Hydrology & Water resource engineering - End Semester Examination - 2022

In the hydrological cycle the average residence time of water in the global

1. Atmospheric moisture is larger than that in the global rivers
2. Oceans is smaller than that of the global ground water
3. Rivers is larger than that of the global ground water
4. Oceans is larger than that of the global ground water

The double mass curve technique is adopted to

1. check the consistency of rain gauge records
2. find the average rainfall over a number of years
3. find the number of rain gauges required
4. estimate the missing rainfall data.

An Isohyet is a line joining points having

1. equal evaporation value
2. equal barometric pressure
3. equal height above the MSL
4. equal rainfall depth in a given duration

Which instrument is used for measurement of Evapotranspiration?

1. Lysimeter
2. Atmometer
3. Phytometer
4. Hygrometer

A hydrograph is a plot of

1. Rainfall intensity against time
2. Stream discharge against time.
3. Cumulative rainfall against time
4. Cumulative runoff against time

The total rainfall in a catchment of area \( 1200 \, km^2 \) during a 6-h storm is 16 cm while the surface runoff due to the storm is \( 1.2 \times 10^3 \, m^3 \). The \( \phi \)-index is

1. \( 0.1 \, cm/h \)
2. \( 1.0 \, cm/h \)
3. \( 0.2 \, cm/h \)
4. cannot be estimated

The discharge per unit drawdown at the well is known as

1. Specific Capacity
2. Specific storage
3. Specific retention
4. Specific yield

The relationship between the duty D in hectare/cumec, the water depth \( \Delta \) in centimetre, and base period B in days, is given by:

1. \( D = \frac{8.64 \times B}{\Delta} \)
2. \( D = \frac{864 \times B}{\Delta} \)
3. \( D = \frac{8.64 \times \Delta}{B} \)
4. \( D = \frac{864 \times \Delta}{B} \)

The Garret's diagrams are based on:

1. Lacey's theory
2. Khosla's theory
3. Bligh's theory
4. Kennedy's theory

During the maintenance of an earthen dam, the apparent seepage through the foundation of the dam is best taken care of, by providing:

1. a chimney drain
2. a rock toe
3. a drain trench along the downstream toe.
4. an upstream impervious cutoff

Differentiate between: (i) confined and unconfined aquifer and (ii) aquiclude and aquitard.

A 20 cm diameter well fully penetrates a confined aquifer of thickness 25 m when the well is pumped at a 200 litres/minute. The steady state drawdown in two observation wells located at 10 m and 100 m distance from pumping well are found to be 3.5 m and 0.05 m, respectively. Calculate the permeability and transmissivity of the aquifer.

Explain evapotranspiration and factors affecting evapotranspiration.

A storm with a 15 cm precipitation produces a direct runoff of 8.7 cm. The time distribution of storm is as follows:

Estimate the value of \( \phi \)-index for the storm.

Describe the salient characteristics of precipitation in India.

The normal annual precipitation of five raingauge stations P, Q, R, S and T are respectively 125 cm, 102 cm, 76 cm, 113 cm, and 137 cm. During a particular storm, the precipitation recorded by stations P, Q, R and S are 13.2 cm, 9.2 cm, 6.8 cm and 10.2 cm respectively. The instrument at station T was inoperative during that storm. Estimate the rainfall at station T during that storm.

Discuss in brief various methods of surface irrigation.

A sandy loam soil holds water at 140 mm/m depth between field capacity and permanent wilting point. The root depth of the crop is 30 cm and the allowable depletion of water is 35%. The daily water use by the crop is 5 mm/day. The area to be irrigated is 60 hectare and water can be delivered at 28 litre per second. The surface irrigation application efficiency is 40%. There are no rainfall and ground water contribution. Determine i) allowable depletion depth between irrigations; ii) frequency of irrigation; iii) net application depth of water and iv) volume of water required.

Define Paleo Irrigation and Kor Watering.

Define Sprinkle Irrigation and Furrow Irrigation.

A water course has a culturable command area of 5000 hectare out of which intensities of perennial sugarcane and rice crop are 25% and 50% respectively. The Duty of these crops at the head of water course are 1000 hectare/cumecs and 1500 hectare/cumecs respectively. Find the discharge required if the peak demand is 125% of the average requirement.

What is meant by canal lining and also discuss its advantages?

A watershed has five non-recording rain gauges, installed in its area. The amount of rainfall recorded for one of the years is given below:

Find the required optimum number of non-recording and recording rain gauges for this watershed. Assume an error of 10% in the estimation of mean rainfall.

Explain the forces acting on the gravity dam.

Explain the causes and effects of waterlogging.

Discuss in detail the application of unit hydrograph.

Following are the ordinates of a storm hydrograph of a river draining a catchment area of \( 423 \, Km^2 \) due to a 6-h isolated storm. Derive the ordinates of a 6-h unit hydrograph for the catchment.