Transcript The Water cycle and its affect on weather

Water Cycle and it’s affects on
weather
Melissa Larkin, Lindsey
Sacksteder, Jen
Schwertman
The water cycle
What is the water cycle?
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The water cycle consist’s of four different
steps:
–
–
–
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Evaporation (Transpiration)
Condensation
Precipitation
Collection (Infiltration)
Evaporation
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Evaporation is when the sun heats up water
in rivers, 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.
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.
Evaporation in Pictures
Condensation
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Water vapor in the air gets cold and changes
back into liquid, forming clouds. This is called
condensation.
Condensation in Pictures
Precipitation
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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.
Precipitation in Pictures
Collection
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When water falls back to earth as
precipitation, it may fall back in the oceans,
lakes or rivers or it may end up on
land. When it ends up on land, it will either
soak into the earth and become part of the
“ground water” that plants and animals use to
drink or it may run over the soil and collect in
the oceans, lakes or rivers where the cycle
starts all over again.
Collection in Pictures
What are Tornadoes?
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Before thunderstorms develop, a change in wind direction and an increase in wind speed
with increasing height creates an invisible, horizontal spinning effect in the lower
atmosphere.
Rising air within the thunderstorm updraft tilts the rotating air from horizontal to vertical.
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An area of rotation, 2-6 miles wide, now extends through much of the storm.
Most strong and violent tornadoes form within this area of strong rotation.
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A lower cloud base in the center of the photograph identifies an area of rotation
known as a rotating wall cloud. This area is often nearly rain-free. Note rain in
the background.
Moments later a strong tornado develops in this
area. Softball-size hail and damaging
"straight-line" winds also occurred with this
storm.
Safety Precautions
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Go into the cellar or basement. If you don’t
have access to either, lay down in a bathtub
and put a mattress over yourself.
The Water Cycle and Hurricanes
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A hurricane is a strong storm that forms in one of the
worlds many oceans. The ideal situation for a
hurricane to form is when the ocean water is warm.
As it is forming in the sea, the warmer the water is
the stronger the hurricane becomes. This means the
places most likely to have hurricanes are the
southern Atlantic Ocean, the Caribbean Sea, the
Gulf of Mexico, and the Eastern Pacific Ocean.
However, Hurricanes can form in any ocean.
Hurricanes in Pictures
Safety Precautions
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Board up all windows and doors. Lock up
cabinets so nothing falls out.
If serious and recommended by officials,
evacuate.
The water cycle and floods
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As soon as water makes contact with the earth, it is forced by
the pull of gravity to seek the lowest level possible. If the water
is not absorbed into the ground, it will continue to seek out a
lower level. These tributaries eventually meet and form larger
troughs called streams or creeks. In turn these streams may
form large rivers which can carry significant amounts of water.
These rivers must have outlets, which may be oceans or lakes.
Eventually water levels are controlled by evaporation or
absorption into the ground. Every step along the way, from
raindrop to stream to ocean, has developed a natural capacity
and this balance is usually maintained.
More precipitation than normal cause a flood because there is
more water the river, but the river cant hold all of it, so it floods
over
Floods in Pictures
Safety Precautions
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In most small scale floods, stay on upper
levels of house or city
If serious enough, Evacuate
The water cycle and drought
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A drought is a period of abnormally dry weather that
lasts long enough to produce a serious imbalance in
the water cycle. A drought is defined and measured
in relation to normal climate conditions. The specific
factors that define droughts are rainfall amounts,
vegetation conditions, agricultural productivity, soil
moisture, reservoir levels, changes in river and
stream flows and economic impacts. Droughts can
last for many years and have devastating effects on
agriculture, water supplies and the economy.
Droughts in Pictures
Safety precautions
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Cut water off to decorative fountains and ponds;
• Only allow irrigation on certain days;
• Reduce total irrigation water use;
• Ban on planting new grass or replanting existing
grass areas;
• Total cutoff of all outdoor irrigation;
• Increase costs for excessive water use;
• Ban on filling or maintaining water level in pools
unless they are covered
Quick Overview
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Driven by these air-current cycles, Earth's water supply moves in a
cycle of its own. When the sun heats the oceans, liquid water from the
ocean's surface evaporates into water vapor in the air. The sun heats
this air so that it rises through the atmosphere and is carried along by
wind currents. As this water vapor rises, it cools down again,
condensing into droplets of liquid water. Collections of these droplets
are called clouds. If a cloud moves into a cooler environment, more
water may condense onto these droplets. If enough water accumulates
in this way, the droplets become heavy enough that they fall through
the air as precipitation. Some of this water collects in large,
underground reservoirs, but most of it forms rivers and streams that
flow into the oceans, bringing the water back to its starting point.
Works cited
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http://science.howstuffworks.com/flood1.htm
http://ims.ode.state.oh.us/ODE/IMS/Lessons/
Content/CSC_LP_S01_BC_L07_I09_01.pdf
http://school.discoveryeducation.com/lesson
plans/programs/ragingplanet-hurricane/
http://www.nssl.noaa.gov/edu/safety/tornado
guide.html
THE END