THE WATER PLANET

I. THE GEOGRAPHY OF WATER

A. Water is one of our most important resources.– 1. Water is essential for agriculture.

a. Irrigation is watering land through pipes, ditches, or canals.

b. Major agricultural states, such as Texas, California, and Arizona, rely on irrigation.

– 2. Water is a valuable power source. a. Hydroelectricity is produced when water drives

turbines to produce electric power.

Grand Coulee DamThree Gorges Dam (Yangtze)

b. Ocean, rivers, and lakes provide a valuable transportation network.

c. Most industries rely on water.

B. Characteristics of water.– 1. Water is the only substance that can exist as a liquid,

solid, or gas within the earth’s temperature range.

– 2. Water has the ability to dissolve almost anything over time, including rocks.

– 3. Water heats and cools very slowly.

C. Water is not evenly distributed on the earth.– 1. The oceans contain 97 percent of the earth’s water. – 2. More than 2 percent of the earth’s water is frozen in

the polar ice caps.

– 3. Less than 1 percent of the earth’s water is available as a freshwater resource.

a. Found underground or in lakes, rivers and streams. b. A small amount in the atmosphere and biosphere.

D. The hydrologic cycle is the circulation of water among parts of the hydrosphere.– 1. The hydrologic cycle is driven by solar

energy.

– 2. Most water enters the atmosphere after being heated by the sun and evaporating from the ocean.

– 3. Evaporation causes water vapor that rises into the air.

– 4. As water vapor rises, it cools and condenses. a. It changes from a gas to tiny liquid

droplets. b. Droplets join to form clouds. c. If the droplets become heavy enough,

they will fall back to the ocean as precipitation.

E. Some precipitation falls on continents and islands.– 1. Some precipitation falls as snow on high

mountains or polar areas.– 2. Some precipitation flows off into rivers,

streams, or lakes.

– 3. The ground absorbs some precipitation where it can be used by plants.

a. When plants give off water vapor through their leaves, it is called transpiration.

b. Evapotranspiration, the combined evaporation of water from the ground with the transpiration of water by plants, is the measure of the total loss of water from the land to the atmosphere.

What is condensation? What is evaporation? What is evapotranspiration? What percent of the earth is covered with water? What percentage of earths’ water is in the ice cap? What percentage of earths’ water is a freshwater

resource?

What is transpiration?How does the water cycle affect life?What percentage of earths’ water is in the

ocean? How does water exist on earth? (3-ways)Hypothesize life without water?

Stop complaining we are finished for today! (9-18-07)

What is transpiration?How does the water cycle affect life?What percentage of earths’ water is in the ocean? How does water exist on earth? (3-ways)Hypothesize life without water? What is condensation? What is evaporation? What is evapotranspiration?

What percent of the earth is covered with water? What percentage of earths’ water is in the ice cap? What percentage of earths’ water is a freshwater

resource?

II. WATER RESOURCES

A. Surface water

– 1. Headwaters a. Are formed from runoff of precipitation down the slopes of

hills and mountains toward the lowlands and coasts. b. Are the first and smallest streams to form from this runoff.

– 2. Tributaries are any smaller streams or rivers that flow into a larger stream or river.

– 3. A watershed is an area of land that is drained by a river and its tributaries.

– 4. Rivers are a valuable water resource, providing water for agriculture, electricity, transportation.

– 5. An estuary is where rivers meet an arm of the sea. a. Estuaries are semi-enclosed bodies of fresh water

and seawater. b. Estuaries are rich in fish and shellfish.

– 6. Lakes a. Are formed when runoff is slowed or stopped

inland and water fills a depression on the land surface. b. Are mostly freshwater, except for some, such as the

Great Salt Lake in Utah, which are salty.

c. Are different from seas.– i. Lakes are totally surrounded by land.– ii. Lakes are usually not at sea level.– III. Lakes do not exchange water with oceans.

d. Are formed in different ways.– i. By glaciers.– ii. In erupted volcanoes.

– 7. Wetlands are land areas that become flooded for at least part of the year.

a. Some of the earth’s most productive lands are wetlands.

b. Florida’s Everglades is one of the best-known wetlands in the United States.

B. Groundwater– 1. Groundwater is a large freshwater resource beneath the surface

of the land found in tiny spaces between rocks and soil.

– 2. The major source of groundwater is precipitation.

a. Water seeps downward and stops when there is no more space between rock grains or when all the spaces are saturated with water.

b. The top of this saturated zone is called the water table.

c. To tap groundwater, a well must be drilled below the water table.

– 3. Groundwater generally flows through layers of rocks. a. Forms an aquifer. (underground river) b. Source of stored water.

Know the following– Aquifer– Groundwater– Tributary– Estuary– Water Table– Wetlands– Headwaters– Lakes– Seas

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C. The oceans.– 1. Oceans cover about 72 percent of the earth’s surface.– 2. Oceans are actually one continuous global body of

water surrounding the continents.

– 3. For geographic identification, this global ocean is divided into four oceans.

a. Pacific Ocean. b. Atlantic Ocean. c. Indian Ocean. d. Arctic Ocean.

– 4. Sizes of the oceans. a. The Pacific Ocean is the largest geographical

feature on the earth, covering an area larger than all the continents combined.

b. The Atlantic and Indian oceans are each about half the size of the Pacific.

c. The Arctic Ocean is the smallest ocean.

– 5. Smaller bodies of salt water. a. Seas are connected to the oceans. b. Gulfs are near coasts and extend into the land. c. Bays are inlets of seas.

– 6. The depth of the oceans varies greatly. a. The greatest ocean depth is in the Mariana’s Trench, located

in the North Pacific Ocean. b. The most shallow part of the ocean is the continental shelf,

which slopes gently downward from the continents.

D. Characteristics of seawater.– 1. Seawater contains every element known on earth,

even gold.– 2. Salts are the most common material found in

seawater.

a. About 3.5 percent of seawater is dissolved salts. b. Because of its salt content, people cannot use seawater

for drinking or for agriculture. c. It is possible, but very expensive, to remove salt from

seawater.(Desalinization plants)

– 3. Oceans do not have the temperature extremes of land.– 4. The ocean waters are always moving and circulating.

What does a desalinization plant do?What part does the ocean play in our global

energy system?What is the deepest part of the ocean?Where is the shallowest part of the oceans?

What is the most common material found in seawater?

What are the four oceans?What is the largest geographical feature on

earth?What percentage of earth is covered by the

oceans?

No More NOTES (Today) (9-20-07)