# Engineering Hydrology MCQ (Multiple Choice Questions)

1. What is the unit of discharge in hydrology?
a) Liters per minute (L/min)
b) Gallons per hour (gal/hr)
c) Cubic feet per minute (ft3/min)
d) Cubic meters per second (m3/s)

Explanation: Discharge is commonly measured in cubic meters per second (m3/s) in hydrology. It represents the volume of water passing through a cross-section of a river or stream per unit of time.

2. Which is not a form of precipitation?
a) Water vapour
b) Hail
c) Drizzle
d) Snow

Explanation: Hail, snow and drizzle are different forms of precipitation. Water vapour is obtained when water from the surface of Earth evaporates into the atmosphere. So, water vapour is not a form of precipitation. Other forms of precipitation are rain, sleet and glaze.

3. Which of the following is not a common use of unit hydrographs?
a) Extending flood flow records based on rainfall
b) Flood forecasting and warning systems
c) Estimation of time of concentration
d) Design of hydraulic structures

Explanation: The time of concentration cannot be directly calculated from the unit hydrograph but can be depicted as the time from the end of excess rainfall to the inflection point on the recession limb. The time of concentration is calculated from empirical equations like Kirpich equation.

4. Which factors govern the shape of hydrograph?
a) Climatic and physiographic factors
b) Climatic factors
c) River characteristics
d) Physiographic factors

Explanation: The shape of the hydrograph depends upon many factors. These factors have been grouped into two basic categories which are climatic factors and physiographic factors. The varied characteristics of the factors are responsible for the variation of the hydrograph.

5. What is ground rainfall?
a) Difference between total rainfall and excess rainfall
b) Difference between total rainfall and intercepted rainfall
c) Difference between total rainfall and infiltration
d) Difference between total rainfall and runoff

Explanation: When rain starts falling, the total rainfall does not reach the ground surface. Some amount of rainfall is intercepted by buildings, trees, and many more objects. Thus, the difference between total rainfall and intercepted rainfall is called ground rainfall.

6. According to Dalton’s law of evaporation, the process of evaporation ceases when which of the following conditions is met?
a) Saturation vapour pressure = atmospheric pressure
b) Saturation vapour pressure < actual vapour pressure
c) Saturation vapour pressure > actual vapour pressure
d) Saturation vapour pressure = actual vapour pressure

Explanation: Evaporation takes place as long as the vapour pressure is less than the saturated vapour pressure. Once the relative humidity reaches 100%, the air no more has the ability to hold the vapours and this leads to condensation.

7. Which of the following is not a disadvantage of a floating evaporation pan?
a) Low maintenance cost
b) Difficulty in taking readings
c) Impact of wave action
d) High installation cost

Explanation: The provision of diagonal baffles in the pan somewhat reduce the surging effect due to wave action but it still causes a problem. The other disadvantages of a floating pan are its high installation and maintenance costs and difficulty in taking measurements and observing readings.

8. Which of the following external changes cause the rate of transpiration to decrease?
a) Increase in sunlight
b) Increase in temperature
c) Increase of carbon dioxide concentration
d) Increase of available soil water

Explanation: Increase in temperature, sunlight and soil water help in increasing the rate of transpiration from a plant. However, an increase in carbon dioxide concentration causes the stomata to close and retards the transpiration process.

9. Which of the following factors is least significant while selecting a point for streamflow measurement?
a) Width of stream
b) Depth of stream
c) Presence of curve
d) Scouring effect on riverbank

Explanation: The process of measuring the flow of a stream at any point by setting up a gauge post on one of its banks, is known as stream gauging. The factors to be considered for a suitable gauge point are; minimum stream width, site not on curve, and no scouring effect on the banks.

10. What is the definition of a flood according to Gumbel?
a) 29th largest flow in a year
b) Sum of three largest daily flows in a year
c) Largest flow of a particular month in a year
d) Largest of 365 daily flows in a year

Explanation: According to Gumbel, a flood is defined as the largest of 365 daily flows in a year and the annual flood series is a group of these values for a number of successive years.

11. Which of the following is not true regarding spillway design flood?
a) Used for the design of spillway of a dam
b) Maximum discharge that can be passed through a dam without damage
c) Used for the design of a hydrologic structure
d) Maximum discharge that can be passed through a dam without affecting its stability

Explanation: A spillway is a hydrologic structure present near dams to help with the release of water. Spillway design flood is a quantity that is specially used for the design of spillways. It also signifies the maximum water that a structure can withstand without damage or instability.

12. Which of the following are known as the formation constants of an aquifer?
a) Storativity and permeability
b) Permeability and specific storage
c) Specific storage and transmissibility
d) Transmissibility and storativity

Explanation: The storage coefficient of an aquifer is also known as the storativity. It along with the transmissibility are called the formation constants of an aquifer. Together they play an important part in the unsteady flow of water through the porous medium.

13. What does the term “runoff coefficient” represent in hydrology?
a) The fraction of rainfall that becomes direct runoff
b) The ratio of peak discharge to total rainfall
c) The speed at which water flows in a channel
d) The percentage of precipitation lost to evaporation

Explanation: The runoff coefficient represents the fraction of rainfall that becomes direct runoff over a certain area.

14. Which of the following is not an example of artificial aquifer recharge?
a) Subsurface dykes
b) Percolation tanks
c) Sprinklers
d) Injection wells

Explanation: Sprinklers are used in irrigation and it causes recharge naturally even though the supply is artificial. This is incidental recharge. The common methods of artificial recharge are spreading, injection wells, subsurface dykes, percolation tanks, check dams, etc.

15. Which hydrological method is commonly used for estimating flood peaks in ungauged watersheds?
a) Rational Method
b) SCS Curve Number Method
c) HEC-RAS Modeling
d) Unit Hydrograph Method

Explanation: SCS Curve Number Method is often used for estimating flood peaks in ungauged watersheds.

16. Which of the following is a method used to estimate potential evapotranspiration?
a) Hazen-Williams equation
b) Manning’s equation
c) Chezy’s equation
d) Thornthwaite equation

Explanation: The Thornthwaite equation is a method used to estimate potential evapotranspiration.

## Chapterwise Multiple Choice Questions on Engineering Hydrology

Our 1000+ MCQs focus on all topics of the Engineering Hydrology subject, covering 100+ topics. This will help you to prepare for exams, contests, online tests, quizzes, viva-voce, interviews, and certifications. You can practice these MCQs chapter by chapter starting from the 1st chapter or you can jump to any chapter of your choice.

## 1. MCQ on Precipitation

The section contains multiple choice questions and answers on precipitation, characteristics of precipitation in India, measurement of precipitation, raingauge network, precipitation data preparation, presentation of rainfall data, mean precipitation over an area, depth-area-duration relationships, frequency of point rainfall, intensity-duration frequency relationship, and probable maximum precipitation in hydrology.

## 2. Engineering Hydrology MCQ on Snowfall and Snow Melt

The section contains multiple choice questions and answers on snowfall and its measurement, the rainfall-runoff process, runoff, surface runoff, yield of a drainage basin, base flow, groundwater depletion curve, and direct runoff hydrograph in hydrology.

## 3. Hydrograph

The section contains MCQs on factors affecting flood hydrographs, hydrograph components, unit hydrograph, derivation of unit hydrographs, and the use and limitation of unit hydrographs. It also covers synthetic unit hydrograph and the discussion of the instantaneous unit hydrograph (IUH) in hydrology.

## 4. MCQ on Evaporation and Transpiration

The section contains Engineering Hydrology multiple choice questions and answers on the evaporation process, evaporimeters, empirical evaporation equations, analytical methods of evaporation estimation, reservoir evaporation and methods for its reduction, transpiration, evapotranspiration, measurement of evapotranspiration, and potential evapotranspiration.

## 5. Engineering Hydrology Multiple Choice Questions on Streamflow Measurement

The section contains questions and answers on on various aspects of streamflow measurement, including stage measurement, velocity measurement, area-velocity method, and the dilution technique of streamflow measurement.

## 6. Engineering Hydrology Questions on Floods

The section contains MCQs on floods, covering topics such as the Rational Method, empirical formulas, flood frequency studies, Gumbel’s Method, partial duration series, regional flood frequency analysis, data for frequency studies, design flood, design storm, and considerations of risk, reliability, and safety factor.

## 7. Flood Routing

The section contains Engineering Hydrology multiple choice questions and answers on flood routing equations, hydrologic storage routing (level pool routing), hydrologic channel routing, and the hydraulic method of flood routing. Additionally, it explores topics related to flood control.

## 8. Engineering Hydrology MCQs on Groundwater

The section contains questions and answers on forms of subsurface water, aquifer properties, geologic formations as aquifers, compressibility of aquifers, groundwater equation of motion, groundwater wells, steady and unsteady flow into a well, open wells, confined aquifers, well loss, specific capacity, recharge, and groundwater resource.

If you would like to learn "Engineering Hydrology" thoroughly, you should attempt to work on the complete set of 1000+ MCQs - multiple choice questions and answers mentioned above. It will immensely help anyone trying to crack an exam or an interview.

Wish you the best in your endeavor to learn and master Engineering Hydrology!

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