Download Water Cycle

Water Cycle
Bell Work:
Where does the water
cycle get its energy
from?
What is the water cycle?
• The water cycle describes
the existence and
movement of water on, in,
and above the Earth.
• Water is always in motion
• Water is always changing
states
– Liquid
– Solid
– gas
Hydrologic Cycle
• The water cycle can also be called the Hydrologic
Cycle…WHY?
• Since the water cycle is truly a "cycle," there is no
beginning or end.
• Water can change states among liquid, vapor, and
ice at various places in the water cycle
• These processes have been happening over
millions of years.
• The water in the apple you ate yesterday may have
fallen as rain half-way around the world last year
or could have been used 100 million years ago by
Mama Dinosaur to give her baby a bath.
Components of the Water Cycle
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Water storage in oceans
Evaporation
Sublimation
Evaporation
Water in the atmosphere
Condensation
Precipitation
Water storage in ice and snow
Snowmelt runoff to streams
Surface runoff
Stream flow
Freshwater storage
Infiltration
Ground-water storage
Ground-water discharge
Springs
Water storage
• 96.5% of the water on
earth is in the oceans
• 3.5% of the water on
earth is fresh
• 90% of the evaporated
water contained in the
water cycle came from
the ocean
• Ice caps and glaciers
Evaporation
• Evaporation is when the sun heats up
water in rivers or lakes or the ocean and
turns it into vapor or steam.
• The water vapor, or steam, leaves the
river, lake or ocean and goes into the
air.
• 90% comes from oceans, seas, lakes
and rivers
• 10% comes from plants: transpiration
• Humidity
• Evaporation removes heat from the
environment: HOW??
• Once evaporated, a water molecule
spend about 10 days in the air.
Sublimation
• Sublimation: The change of
snow or ice to water vapor
without melting
• Solid  gas
• High amounts of energy is
needed….Where would this
energy come from???
• South side of Mt. Everest:
– Low temperatures
– Strong winds
– Intense sunlight
– Low air pressure
Transpiration
• Transpiration is the process by which
plants lose water out of their leaves.
• Transpiration gives evaporation a bit of a
hand in getting the water vapor back up
into the air
• Moisture is carried through plants from
roots to small pores on the underside of the
leaves, where it changes to vapor and is
released to the atmosphere.
• A large oak tree can transpire 40,000 gallons
of water a year.
• Factors that effect Transpiration:
– Temperature
– Relative humidity
– Wind and air movement
– Soil-moisture availability
– Types of plants
Water in the atmosphere
• The atmosphere always
contains water
• Tiny water particles are
too small to see
UNLESS….
• Clouds
• Superhighway used to
move water around the
globe
Condensation
• Condensation: Water vapor in the air gets
cold and changes back into liquid, forming
clouds.
• Responsible for the formation of CLOUDS
• Vapor  liquid
• Condensation is the opposite of evaporation
• Fog
• Moisture on your windows or drink
– Water vapor in the warm air, turns
back into liquid when it touches the
cold glass
Precipitation
• Precipitation: Occurs
when so much water has
condensed that the air
cannot hold it anymore.
• The clouds get heavy and
water falls back to the earth
in the form of rain, hail,
sleet or snow
• Millions of cloud droplets
are required to make a
single raindrop
Precipitation Rates Vary by location
Surface Runoff
• Surface Runoff: Occurs as precipitation travels
over the soil surface to the nearest stream channel.
• Run over the soil and collect in the oceans, lakes
or rivers where the cycle starts
• Ground saturation
• Flash flood
• Deposition can happen during this time….What
was that??
• Dangerous time for pollution to occur
A
watershed is
an area of
land where
all of the
water that
falls in it and
drains off of
it goes into
the same
place.
Groundwater
• A portion of the water that falls as precipitation
can infiltrate (seeps into) the subsurface soil and
rock.
• Used by plants and burrowing animals
• Keeps soil cool during the summer
Groundwater
Air
Water
Unsaturated
Zone
Permeable
Layers
Water Table
Saturated Zone
Solid Rock
Unconnected
Pores
Impermeable
Layer
Water Table
• The top of the surface where ground water occurs is
called the water table
Aquifer
• An underground layer of water-bearing porous
stone, earth, or gravel
Groundwater
Spring
Artesian Well
Aquifer
Aquifer
Water
Table
Aquifer
Impermeable
Rock
Dry
Well
Well