Transcript The Water Cycle Causes Change
Slide 1
The Water Cycle Causes
Change
Objective 2.02
Investigate and discuss the role of the water cycle and how
movement of water over and through the landscape helps shape land
forms.
Slide 2
• Moving water is a powerful agent of
change. It moves with great force,
changing the land in the process. Moving
water shapes all different kinds of
landforms. Underground water erodes
rocks and forms caves. Ocean waves
erode beaches and change the shape of
the coastlines. The type of landform
created depends on how water moves on
the surface.
Slide 3
The Water Cycle
• Water is found everywhere on Earth. You drink
water every day. Water also falls from the sky as
rain. The ocean is full of salt water. These are
three sources of water. They are all connected to
one another. Water moves over the Earth’s
surface, under the ground, and in the
atmosphere. This cycling of water is called the
water cycle! It happens when water moves
between the Earth and the atmosphere.
Slide 4
The Water Cycle
Slide 5
• How does the water cycle work?
Precipitation in the form of rain, ice,
snow, or dew falls to the Earth. There it
soaks into the ground, runs off of rocks
and structures, or accumulates in bodies
of water.
Slide 6
• The Sun provides energy in the form of heat,
which drives evaporation. Evaporation is the
process that changes liquid water to gaseous
water. Gaseous water is called water vapor.
The process of evaporation removes water from
the Earth. It dries the ground, rocks, and
structures. It also lowers the levels of bodies of
water. In fact, small bodies of water, like puddles
and rivulets, usually evaporate completely.
Plants and animals also send a small amount of
water into the atmosphere.
Slide 7
• The water vapor rises into the
atmosphere. As it rises, it cools. When it
cools, it begins to condense into clouds.
Condensation changes water from a gas
(water vapor) to a liquid. The clouds
eventually become saturated with (full of)
water. At that point, the water is released
from the clouds as precipitation, which
starts the cycle all over again!
Slide 8
The Effects of Moving Water
• The water cycle is a continuous cycle. It never stops.
The water cycle controls how water is distributed on
Earth. Surface water includes rivers, lakes, and
puddles. These are bodies of water. A body of water
is any accumulation of water on the surface. Moving
surface waters, like rivers and creeks, erode soils
and carves a channel in the landscape. Precipitation
and evaporation change the amount of water in a
body of water. Precipitation adds water to the
surface, while evaporation removes water.
Slide 9
• As precipitation falls to the surface, some
of it soaks into the ground. This increases
groundwater flow. The rest moves over the
surface as runoff. Runoff cuts into the
ground as it moves. It carves a visible
channel in the landscape. It strips material
away from the top layer of soil, increasing
soil erosion. The amount of erosion that
occurs depends on the amount and speed
of the water. Heavy downpours or long
periods of rain increase runoff and
erosion.
Slide 10
• Runoff also depends on the soil. Any soil that is
too wet or too dry is likely to increase runoff and
erosion. Some types of soil erode more easily
than others. Areas that receive a lot of
precipitation have moist soil that is compact or
held tightly together. The soil can hold lots of
water and support a diversity of plants.
Vegetation protects the soil by soaking up more
water. It helps to decrease runoff and erosion.
On the other hand, areas that receive very little
precipitation have dry soil. Dry soil is loosely
held together. It cannot hold much water. This
also means it cannot support much vegetation.
Decreased vegetation increases runoff and,
therefore, soil erosion.
Slide 11
Severe Weather Causes Change
• The water cycle drives the weather we
experience every day. It controls the formation of
clouds and precipitation. Severe weather can
change the surface of Earth very quickly. It
increases weathering and erosion. Tornados,
strong winds, and storm surges are a few
examples of severe weather. They damage soil
and move large amounts of soil and other
material long distances. This causes a great
deal of water and wind erosion. Wind and water
also damage human structures.
Slide 12
• When a lot of rain falls over a short period
of time, a flood can occur. A flood is an
increase or overflow of a body of water.
Floods occur when the ground becomes
saturated and runoff increases
significantly. Floods are powerful forces of
erosion. They move tons of sediment and
other larger material, sometimes very long
distances.
Slide 13
• A flood that rises and falls rapidly is called a
flash flood. Flash floods can occur without
warning are very dangerous. They can
change the land very quickly. Flash floods
are caused by heavy rainfall in a small
area. The failure of a dam or the thawing of
snow or ice can also cause a flash flood.
Slide 14
• A lack of rain can cause a drought.
Droughts are long periods of dry weather.
During a drought, the Sun still heats the
surface, but no precipitation falls. This
makes everything dry. During a drought,
the level of even large bodies of water, like
lakes, drops substantially.
Slide 15
• Because water is scarce in drought areas,
wind erosion is the greatest threat. Wind
erosion can be observed best in deserts.
Wind picks up and carries loose sand to
new places. The deposition of sand forms
large sand dunes.
Slide 16
• Precipitation can increase the chance of a
landslide. Recall that a landslide occurs
when a pile of weathered material gives
away to gravity and falls down the side of
a mountain. As precipitation falls to the
ground, the water adds to the weight of the
pile, making it heavier. The added weight
increases the force of gravity acting on the
pile. This can be enough to trigger the next
landslide.
Slide 17
The End
The Water Cycle Causes
Change
Objective 2.02
Investigate and discuss the role of the water cycle and how
movement of water over and through the landscape helps shape land
forms.
Slide 2
• Moving water is a powerful agent of
change. It moves with great force,
changing the land in the process. Moving
water shapes all different kinds of
landforms. Underground water erodes
rocks and forms caves. Ocean waves
erode beaches and change the shape of
the coastlines. The type of landform
created depends on how water moves on
the surface.
Slide 3
The Water Cycle
• Water is found everywhere on Earth. You drink
water every day. Water also falls from the sky as
rain. The ocean is full of salt water. These are
three sources of water. They are all connected to
one another. Water moves over the Earth’s
surface, under the ground, and in the
atmosphere. This cycling of water is called the
water cycle! It happens when water moves
between the Earth and the atmosphere.
Slide 4
The Water Cycle
Slide 5
• How does the water cycle work?
Precipitation in the form of rain, ice,
snow, or dew falls to the Earth. There it
soaks into the ground, runs off of rocks
and structures, or accumulates in bodies
of water.
Slide 6
• The Sun provides energy in the form of heat,
which drives evaporation. Evaporation is the
process that changes liquid water to gaseous
water. Gaseous water is called water vapor.
The process of evaporation removes water from
the Earth. It dries the ground, rocks, and
structures. It also lowers the levels of bodies of
water. In fact, small bodies of water, like puddles
and rivulets, usually evaporate completely.
Plants and animals also send a small amount of
water into the atmosphere.
Slide 7
• The water vapor rises into the
atmosphere. As it rises, it cools. When it
cools, it begins to condense into clouds.
Condensation changes water from a gas
(water vapor) to a liquid. The clouds
eventually become saturated with (full of)
water. At that point, the water is released
from the clouds as precipitation, which
starts the cycle all over again!
Slide 8
The Effects of Moving Water
• The water cycle is a continuous cycle. It never stops.
The water cycle controls how water is distributed on
Earth. Surface water includes rivers, lakes, and
puddles. These are bodies of water. A body of water
is any accumulation of water on the surface. Moving
surface waters, like rivers and creeks, erode soils
and carves a channel in the landscape. Precipitation
and evaporation change the amount of water in a
body of water. Precipitation adds water to the
surface, while evaporation removes water.
Slide 9
• As precipitation falls to the surface, some
of it soaks into the ground. This increases
groundwater flow. The rest moves over the
surface as runoff. Runoff cuts into the
ground as it moves. It carves a visible
channel in the landscape. It strips material
away from the top layer of soil, increasing
soil erosion. The amount of erosion that
occurs depends on the amount and speed
of the water. Heavy downpours or long
periods of rain increase runoff and
erosion.
Slide 10
• Runoff also depends on the soil. Any soil that is
too wet or too dry is likely to increase runoff and
erosion. Some types of soil erode more easily
than others. Areas that receive a lot of
precipitation have moist soil that is compact or
held tightly together. The soil can hold lots of
water and support a diversity of plants.
Vegetation protects the soil by soaking up more
water. It helps to decrease runoff and erosion.
On the other hand, areas that receive very little
precipitation have dry soil. Dry soil is loosely
held together. It cannot hold much water. This
also means it cannot support much vegetation.
Decreased vegetation increases runoff and,
therefore, soil erosion.
Slide 11
Severe Weather Causes Change
• The water cycle drives the weather we
experience every day. It controls the formation of
clouds and precipitation. Severe weather can
change the surface of Earth very quickly. It
increases weathering and erosion. Tornados,
strong winds, and storm surges are a few
examples of severe weather. They damage soil
and move large amounts of soil and other
material long distances. This causes a great
deal of water and wind erosion. Wind and water
also damage human structures.
Slide 12
• When a lot of rain falls over a short period
of time, a flood can occur. A flood is an
increase or overflow of a body of water.
Floods occur when the ground becomes
saturated and runoff increases
significantly. Floods are powerful forces of
erosion. They move tons of sediment and
other larger material, sometimes very long
distances.
Slide 13
• A flood that rises and falls rapidly is called a
flash flood. Flash floods can occur without
warning are very dangerous. They can
change the land very quickly. Flash floods
are caused by heavy rainfall in a small
area. The failure of a dam or the thawing of
snow or ice can also cause a flash flood.
Slide 14
• A lack of rain can cause a drought.
Droughts are long periods of dry weather.
During a drought, the Sun still heats the
surface, but no precipitation falls. This
makes everything dry. During a drought,
the level of even large bodies of water, like
lakes, drops substantially.
Slide 15
• Because water is scarce in drought areas,
wind erosion is the greatest threat. Wind
erosion can be observed best in deserts.
Wind picks up and carries loose sand to
new places. The deposition of sand forms
large sand dunes.
Slide 16
• Precipitation can increase the chance of a
landslide. Recall that a landslide occurs
when a pile of weathered material gives
away to gravity and falls down the side of
a mountain. As precipitation falls to the
ground, the water adds to the weight of the
pile, making it heavier. The added weight
increases the force of gravity acting on the
pile. This can be enough to trigger the next
landslide.
Slide 17
The End