PART 2: HYDROMETEOROLOGY Flashcards
the water cycle on the earth consisting of a continuous movement of moisture over, through, and beneath the surface
hydrologic cycle
is varied form of moisture that occur in the atmosphere
precipitation
quite uniform precipitation with drop less than 0.5mm in diameter
drizzle
water particles as large as 7mm in diameter
rain
grouping of small ice crystals (snowflakes)
snow
forms when raindrops are falling through air having a temperature below freezing
sleet
accumulating thin layer of ice
hail stone
water at the soil surface by direct condensation and absorption from the atmosphere
dew
measures the depth and intensity of rain falling on a flat surface
raingage
vertical, cylindrical container with top openings 203 mm (8in) in diameter
raingage
also known as a non-recording gage, has the same diameter at the rim as a standard non-recording rain gage
storage rain gage
allows for continuous measurements of rainfall amounts, which then can be used to determine the time duration, intensity and amount of rainfall for each storm event
recording rain gage
is used primarily for remotely measuring rainfall
tipping bucket rain gage
generally should be located on a flat area, with the opening oriented so that the rainfall is measured in terms of depth that accumulates over a flat surface
rain gage
recorded by individual rain gages in an area
arithmetic average
weighted method
thiessen method
lines of equal rainfall
isohyetal method
entry of water into the soil surface; has high initial rate that diminishes with time
infiltration
size of the particles that make-up the soil
soil factor
surface sealing is reduced by vegetation and increases infiltration
vegetation
a decay type function due to decrease in soil profile storage potential, washing of fine soil particles into the soil voids, and swelling of soil colloids and closing of soil cracks
horton equation
transfer of liquid water into the atmosphere
evaporation
process through which water vapor passes into the atmosphere through the tissues of living plants
transpiration
consumptive use of crops
evapotranspiration
recognizes the water moves away from evaporating and transpiring surface in response to turbulent gradient
mass transfer approach
total annual runoff output
water yield
total annual runoff output
water yield
is a graphical or tabular representation of runoff rate against time
hydrograph
time between the center of mass for a rainfall event and the peak streamflow rate
time to peak
time between the center of mass for a rainfall event and the peak streamflow rate
time to peak
preferred for measuring small watersheds, especially those in which the streamflows become quite low
weirs
can be constructed from concrete treated wood, concrete blocks, and metals
weirs and flumes
generally is a steel blade set into concrete
notch of a weir
used in situations where sensitivity to low streamflows is not critical and where a sharp-crested weir might be damaged by sediment or other debris
broad-crested weir
often used where accurate measurements of low streamflows are required
sharp-crested v-notch weir
refers to the physical characteristics, dissolved chemical constituents, and bacteriological quality of water, with reference to a specific use
water quality
found in both igneous and sedimentary rocks is leached readily into surface water and groundwater systems
sodium
is a requirement for plant growth and is cycled by aquatic vegetation
potassium
occurs naturally in water from the leaching of common igneous and sedimentary rocks
sulfur
often are used to determine if water can be utilized for drinking, swimming, and other forms of human contact
bacteriological quality
should not be used interchangeably with the word “standard” in water quality measures
criterion
monitoring which is conducted to determine the effects of specific actions on water quality constituents
cause and effect monitoring
monitoring undertaken to help a watershed manager if there are specific trends in water quality
baseline monitoring
monitoring conducted to determine if specified water quality standards are being adhered to
compliance monitoring
monitoring designed to indicate the existing water quality conditions
inventory monitoring
the average conditions of weather patterns, over a period of years, as measured by rainfall…
climate
a set of atmospheric conditions for a specified time
weather
a measure of degree of hotness or coldness of the air
air temperature
is mercury-filled and has a small constriction in the fine bore of the tube above the bulb
maximum thermometer
alcohol-filled has a small glass index rod floating in the bore
minimum thermometer
a continuous record of air temperatures frequently is an essential requirement in describing the climate of a region
thermograph
is a ratio of the actual amount of water vapor in the air compared to the total amount of water vapor that is necessary for saturation
relative humidity
used to measure relative humidity
psychrometer
operate on the principle of cooling by evaporation
wet-and-bulb thermometers
are instruments that measure and record the relative humidity on a continuous basis
hygrometers
simultaneously and continuously measures and records the air temperature and RH
hyrgrothermograph
the net loss of water from a surface surface by means of a change in the state of water from a liquid to a vapor
evaporation
measurement of evaporation that is a technique widely used by plant ecologists
atmometer
measures the transpiration rates of a plant often in employed by watershed managers
phytometer
a direct measurement of actual evapotranspiration can be obtained by analyzing the water balance for a block of soil
lysimeter
air in motion
wind
instrument used to measure wind direction
wind vane
refers to any instrument that measures radiation, regardless of the wavelength
radiometer
____ if its flat receptor is sensitive to both hemispheres, and as a result, measures the radiant flux density between them
- absorbs radiation of all wavelengths directed downward and upward
net radiometer
is the amount of energy received on a unit surface in a unit of time
radiant flux density
is equipped with a flat receptor that is open to only a hemisphere
total hemispherical radiometer
consists of a glass globe that acts as a magnifying glass, focusing a beam of sunlight onto a special recording paper when the sunlight is sufficiently strong
sunshine duration