Water on the Water on the Earth NotesEarth Notes

Earth Science Earth Science

Grade 8Grade 8

The Earth is the only planet in the The Earth is the only planet in the solar system to be covered in solar system to be covered in waterwater..

Water covers about Water covers about 75%75% of the of the Earth’s surface.Earth’s surface.

Any place on the Earth that contains Any place on the Earth that contains water is called the water is called the hydrospherehydrosphere..

Of the water on the Earth, Of the water on the Earth, 97%97% is is salt water and salt water and 3%3% is fresh. is fresh.

Almost 67% of all the fresh water is Almost 67% of all the fresh water is locked up in locked up in glaciersglaciers near the North near the North and South Poles.and South Poles.

That leaves just That leaves just 1%1% of all the water of all the water on the planet available for plants on the planet available for plants and animals to live on. and animals to live on.

Water PercentagesWater Percentages

Fresh water

salt water

97%97%

3%

Fresh w ater inglaciers

fresh w ater availableto use

67% 67% locked locked in in glacierglacierss

33% available to use

33% of 3% = only 1% for all plants and animals to use

Water constantly moves through the Water constantly moves through the atmosphere by the atmosphere by the water cyclewater cycle. .

Water that does not soak into the Water that does not soak into the ground or evaporate into the ground or evaporate into the atmosphere is called atmosphere is called runoffrunoff..

RUNOFF=RIVERS RUNOFF=RIVERS

Water Cycle AnimationWater Cycle Animation

http://epa.gov/climatechange/kids/http://epa.gov/climatechange/kids/water_cycle_version2.htmlwater_cycle_version2.html

Four factors affecting Four factors affecting absorption of rainabsorption of rain

Amount of rainfallAmount of rainfall

Heavy downpour =A lot of runoff

Light, misty rain=Little run off

Four factors affecting Four factors affecting absorption of rainabsorption of rain

Time span of the rainTime span of the rain 2 inches of rain in 1 hour = a lot of 2 inches of rain in 1 hour = a lot of

runoffrunoff 2 inches of rain in 1 week = little runoff2 inches of rain in 1 week = little runoff

***Four factors affecting ***Four factors affecting absorption of rainabsorption of rain

Slope of the landSlope of the land Steeper the land, the more run offSteeper the land, the more run off Flatter the land, less runoffFlatter the land, less runoff

****Four factors affecting ****Four factors affecting absorption of rainabsorption of rain

Amount of vegetationAmount of vegetation Lots of vegetation = less run offLots of vegetation = less run off No vegetation= more offNo vegetation= more off

Velocity of the RiversVelocity of the RiversFastest at 1) very center of the riverFastest at 1) very center of the river

2)outside of the meander2)outside of the meander

1

2

Erosion/Deposition of a Erosion/Deposition of a RiverRiver

Erosion occurs on the outside of the river Erosion occurs on the outside of the river meandermeander

Deposition occurs on the inside of the Deposition occurs on the inside of the river meanderriver meander

Bed load and Suspended Bed load and Suspended loadload

Bed load: material that rolls along Bed load: material that rolls along the bottom of the riverthe bottom of the river

Suspended load: material that floats Suspended load: material that floats suspended in the watersuspended in the water

Development of an Development of an Oxbow lakeOxbow lake

1.

2.

3.

4.

Oxbow lake: cutoff meander