This set of Engineering Hydrology Multiple Choice Questions & Answers (MCQs) focuses on “Streamflow – Stage Measurement”.
1. Which of the following is not a direct method of streamflow measurement?
a) Area-velocity method
b) Slope-area method
c) Electromagnetic method
d) Ultrasonic method
Answer: b
Explanation: The methods for measuring streamflow are mainly classified into two categories, that is indirect and direct methods. The direct methods involve area-velocity method, electromagnetic method and ultrasonic method.
[/expand]
2. Which of the following is not an indirect method for determination of stream discharge?
a) Dilution technique
b) Slope-area method
c) Weirs
d) Parshall flume
Answer: a
Explanation: The dilution technique is a direct method for determination of streamflow. The indirect methods for streamflow measurement include slope-are method and the use of hydraulic structures like weirs and flumes.
[/expand]
3. Which of the following factors is least significant while selecting a point for streamflow measurement?
a) Depth of stream
b) Width of stream
c) Presence of curve
d) Scouring effect on riverbank
Answer: a
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.
[/expand]
4. What is the surface elevation of a river measured above a fixed reference level is known as?
a) Depth
b) Water table
c) Meander
d) Stage
Answer: d
Explanation: The elevation of the water surface of a river measured above a datum, usually taken as the mean sea level, is known as the stage of the river. It is important parameter for streamflow measurement.
[/expand]
5. Which of the following pairs of instruments are manual gauges for measuring stage?
a) Staff gauge and wire gauge
b) Wire gauge and bubble gauge
c) Float gauge and bubble gauge
d) Float gauge and staff gauge
Answer: a
Explanation: The staff gauge and wire gauge are examples of manual gauges for measuring the stage of a river. They are economical and simple to use. However, they have to be used at regular intervals to measure the variation in stage reliably.
[/expand]
6. Which of the following is not a desirable feature for a manual staff gauge?
a) Durable material
b) Low coefficient of thermal expansion
c) Low coefficient of moisture expansion
d) Flexible
Answer: d
Explanation: The staff gauge is a graduated rod which should be fixed in position. It should be made of a durable material of low coefficient of thermal and moisture expansion, so as to maintain its reliability for giving readings.
[/expand]
7. When the range of water surface elevations is beyond the scope of a single staff gauge, which type of gauge is used?
a) Rigid gauge
b) Adhesive gauge
c) Molded-in gauge
d) Sectional gauge
Answer: d
Explanation: Sectional gauges are not a different type of gauge but defined on the basis of the use of multiple manual staff gauges. Different staff gauges are built in at different locations in the stream so as to maintain a continuity between various measurements.
[/expand]
8. Which of the following is not true with respect to staff gauges?
a) It may be held inclined
b) It must be fixed rigidly to a structure
c) Graduated markings should be accurate and easy to read
d) It measures the water surface elevation from a datum above the surface
Answer: d
Explanation: A staff gauge is fixed rigidly to a structure by positioning it on the river bed and measuring the water surface elevation from the bottom of the river. The measurements may be taken while keeping the staff inclined or vertical.
[/expand]
9. Which of the following is not a part of a manual wire gauge apparatus?
a) Reel and wire
b) Weight
c) Recorder
d) Mechanical counter
Answer: c
Explanation: A wire gauge is a manual gauge which does not record any observations. Unlike a staff gauge the measurements are taken from above the water surface by lowering a weight attached to a wire through a reel. A mechanical counter notes the number of reel rotations and it can be related to the length of the wire drawn out.
[/expand]
10. The general operating range of a wire gauge is more than 100m.
a) True
b) False
Answer: b
Explanation: A wire gauge relies on a thin wire and weight to give reading of river stage. It is only reliable for heights upto 25 m above the water surface. For longer wires, the effect of wind, etc. may come into play to affect the accuracy of the measurements.
[/expand]
Sanfoundry Global Education & Learning Series – Engineering Hydrology.
To practice all areas of Engineering Hydrology, here is complete set of 1000+ Multiple Choice Questions and Answers.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
