Hydrology and Precipitation Analysis

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Questions and Answers

What type of function is usually used to weight each day's precipitation?

Linear function

Quadratic function

Logarithmic function

Exponential or reciprocal function (correct)

What does the area-elevation curve illustrate?

The total rainfall in a region

The average precipitation rate across different elevations

The area of a river basin above a certain elevation (correct)

The elevation of natural features in the basin

How is areal precipitation expressed?

As a percentage of total rainfall

As the total volume of rainwater

As the average depth of liquid water over a specified area (correct)

As the rate of rainfall per second

What does the areal reduction factor of rainfall compare?

Mean point rainfall to mean areal rainfall for the same duration Signup and view all the answers

What is primarily referred to when mentioning 'average' in ordinary usage?

Arithmetic mean Signup and view all the answers

What is average velocity in relation to discharge?

Discharge divided by cross-sectional area at right angles to flow Signup and view all the answers

What does bankfull discharge refer to?

Discharge conveyed without overtopping the banks Signup and view all the answers

How is the base-width of a flood hydrograph defined?

Time interval of direct runoff produced by a storm Signup and view all the answers

What does the term basin response refer to?

The manner in which a basin reacts to meteorological events Signup and view all the answers

What is the purpose of calibration in measurement instruments?

To determine the relationship between quantity measured and instrument indication Signup and view all the answers

What defines a climatic year?

A continuous twelve-month period for a complete climatic cycle Signup and view all the answers

How is channel frequency calculated?

Number of stream segments divided by the basin area Signup and view all the answers

What does the coefficient of determination express?

Proportion of variance of dependent variate explained by independent variates Signup and view all the answers

What is the primary purpose of the station-year method?

To create a single record from multiple independent station records. Signup and view all the answers

Which term describes hydrological processes analyzed through probability theory?

Statistical hydrology Signup and view all the answers

How is storm runoff defined?

Immediate surface runoff that reaches the catchment outlet after rain starts. Signup and view all the answers

What is meant by storm transposition?

Transferring the observed storm pattern to a different but similar basin. Signup and view all the answers

Which equation describes the balance of inflows, outflows, and storage changes in a water body?

Storage equation Signup and view all the answers

What is the storm duration?

The period between the beginning and end of precipitation. Signup and view all the answers

What technique is used to compute the movement of a flood wave through a river?

Stream routing Signup and view all the answers

What does structural flood mitigation refer to?

Physical systems designed to reduce flood impacts. Signup and view all the answers

What defines a normal in meteorological terms?

Period averages calculated over at least thirty consecutive years Signup and view all the answers

What is the meaning of 'n-year event' in hydrology?

A hydrological event with a return period of n years Signup and view all the answers

What characterizes orographic precipitation?

Precipitation caused by moist air ascending orographic barriers Signup and view all the answers

What does the term 'outflow' refer to in hydrology?

The flow of water out of various bodies like streams or reservoirs Signup and view all the answers

In hydrology, what are outliers?

Values that are significantly different from others in the sample Signup and view all the answers

What does 'overbank flow' refer to?

Flow of water over land when streamflow exceeds capacity Signup and view all the answers

What is a 'parameter' in hydrology?

A coefficient involved in hydrological models that can be adjusted Signup and view all the answers

What does 'peak flow' refer to in hydrological terms?

The maximum instantaneous discharge of a hydrograph Signup and view all the answers

What is surface flow?

The part of precipitation that flows on the ground surface. Signup and view all the answers

Which of the following does not contribute to surface retention?

Surface runoff Signup and view all the answers

What distinguishes a totalizer precipitation gauge?

It records measurements only at long-spaced time intervals. Signup and view all the answers

What is the definition of time of concentration in the context of hydrology?

The period required for runoff to reach the outlet from the farthest point in a drainage basin. Signup and view all the answers

What does a Thiessen polygon represent?

Polygons formed by the perpendicular bisectors of lines joining adjacent rainfall stations. Signup and view all the answers

Which term describes the time it takes for a water parcel to travel downstream?

Travel time Signup and view all the answers

What does a synthetic hydrograph use for its development?

Estimation of coefficients based on catchment features. Signup and view all the answers

What is an example of a method used for tracer dilution gauging?

Determining discharge by measuring tracer solution dilution. Signup and view all the answers

What defines a twin-gauge station in hydrology?

A gauging station where two water level gauges monitor the same water body. Signup and view all the answers

What is a unit hydrograph?

A hydrograph of direct runoff resulting from a unit amount of effective rainfall. Signup and view all the answers

Which best describes urban hydrology?

It studies hydrology in areas with significant impervious surfaces due to development. Signup and view all the answers

What does the term 'variance' refer to in statistics?

The second central moment of a frequency distribution. Signup and view all the answers

What is the purpose of the velocity-area method?

To measure discharge by assessing velocities across a stream's cross-section. Signup and view all the answers

Which of the following describes a V-notch weir?

A sharp-crested measuring weir with a downward pointing apex. Signup and view all the answers

What is indicated by water balance in hydrology?

Water gain must equal losses plus changes in storage over time. Signup and view all the answers

What does a velocity curve represent?

The distribution of flow velocity points across a vertical line in a stream. Signup and view all the answers

Study Notes

Hydrology Terminology

Accumulative precipitation gauge: A precipitation gauge used at stations visited infrequently, typically at long intervals.
Active basin area: The basin area excluding undrained parts.
Actual evaporation: The quantity of water evaporated from an open water surface or the ground.
Actual evapotranspiration: The sum of water evaporated from the soil and plants, considering the ground's natural moisture content.
Advection: The process of transferring air-mass properties by atmospheric winds.
Altitude: Vertical distance from mean sea level
Annual exceedence series: Series of values of independent events (e.g., floods), exceeding a specific base value, equal to the number of years recorded.
Annual flood: The highest peak discharge in a water year or the flood exceeded annually on average.
Annual flow: Total volume of water flowing (usually outflow) from a drainage area or river basin in a year.
Annual maximum series: A set of extreme-value series of the largest annual values.
Annual minimum series: A set of extreme-value series of the smallest annual values.
Annual runoff: Total volume of water flowing from a drainage area or river basin in a year.
Annual series: Hydrological element of a characteristic or element for each year.
Annual storage: Volume of water storable in a reservoir.
Annual storage capacity: Maximum volume of water storable in a reservoir.
Antecedent precipitation index: Weighted summation of past daily precipitation amounts, used to gauge soil moisture.

Additional Hydrology Concepts

Arithmetic mean: The sum of values divided by their count.
Area-elevation curve: Curve showing the area of a river basin above a given elevation.
Areal precipitation: Average precipitation depth across a specific geographic area.
Areal reduction factor (of rainfall): Ratio of mean areal rainfall to mean point rainfall.
Arithmetic mean: Sum of values divided by their count.
Automatic station: Station with automated instruments that record or transmit data automatically.
Average velocity: Discharge divided by cross-sectional area (at right angles to flow).
Average year: A year in which the observed hydrological or meteorological quantity equals the long-term average.
Bank-full discharge: Discharge in a water course without overflowing the surrounding banks.
Bank-full stage: Water level when the stream overflows its natural banks.
Base-width (of a flood hydrograph): Time interval between the start and finish of the direct runoff of a storm.
Basin: Drainage area of a stream, river, or lake.
Basin response: Manner in which a drainage basin responds to a meteorological event or series of events.
Basin response: Reaction of a basin to a meteorological event or series of events.
Basin response: How a basin reacts to a meteorological event.
Base width (of a flood hydrograph): Time interval from the beginning to the end of direct runoff.
Base width (of a flood hydrograph): Duration of the direct runoff from the beginning to the end.
Base width (of a flood hydrograph): Interval of time from start to end of direct runoff.
Best approximation: The best guess of the true value, often the mean of multiple calculations.
Bubble gauge: Measuring device using a gas-purged system to measure water levels.
Calibration: Determining the relationship between instrument readings and the measured quantity.
Catchment area / Catchment: Area with a common outlet for surface runoff.
Catchment response: How a basin reacts to meteorological events.
Channel frequency: Number of stream segments of all orders divided by the area.
Channel network: Arrangement of natural or man-made drainage channels.
Clear overflow weir: Weir with unobstructed flow, not submerged by tail water.
Climate: Long-term synthesis of weather conditions.
Climatic change: Significant change in regional climate.
Climatic year: Continuous 12-month period covering a complete climatic cycle.
Climatological station: A station for hydrological purposes which collects additional climatological data.
Coefficient of determination: Square of correlation coefficient, representing the proportion of variance explained.
Coefficient of variation: Ratio of standard deviation to mean, measuring relative variability.
Compound weir: Weir with multiple sections, possibly of different types and dimensions.
Conceptual hydrological model: Simplified representation of hydrological processes.
Conditional probability: Probability of event E given the occurrence of event F (Pr(E/F)).
Confidence interval: Interval likely to include the true value with a specified probability (confidence level).
Confidence level: Probability that a confidence interval contains the true value.
Confidence limits: Values defining the lower and upper bounds of the confidence interval.
Constant-rate dilution gauging: Measuring flow rates by injecting a tracer of known concentration.
Continental hydrology: Study of hydrological processes on continents, focusing on the continental phase of the water cycle.
Continuity equation: Equation expressing conservation of water mass.
Convective precipitation: Precipitation caused by convective atmospheric movements.
Correlation: Interdependence or relationship between two measurable quantities.
Correlation coefficient: Measure of interdependence between two variables.

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Description

This quiz covers essential concepts in hydrology, focusing on precipitation, discharge, and water balance. Examine your understanding of terms like areal precipitation, flood hydrograph, and basin response. Ideal for students studying environmental science and water resource management.