WaterWater

Three-fourths of the Earth’s surface is covered by water.

How much of the Earth’s surface is covered by water?

Drinkable waterDrinkable water

How much of Earth’s water is drinkable?Most of the water on Earth, 97% to be exact, is salt water found in the oceans. Only about 3% is fresh for drinking and irrigation.

WaterWater

The water in your glass may have fallen from the sky as rain just last week, but the water itself has been around pretty much as long as the earth has!  

How old is the water you drank at this morning?

Water PropertiesWater Properties

A water molecule consists of one atom of oxygen bound to two atoms of hydrogen.

States of Matter (phases)States of Matter (phases)

Water can be found as a solid, liquid or gas.

Water's state is determined mostly by temperature.

MoleculesMolecules

Small pieces of water are called molecules. Molecules are always moving.

Solid, liquid, gasSolid, liquid, gas

Solid: The molecules are relatively close to one another, and the motion of each molecule is restricted by its interaction with other molecules.

Liquid: The molecules are further apart and are not arranged in any special order. They are free to move in any direction, but are confined by their container.

Gas: The molecules are further apart and have little interaction with one another.

Density at FreezingDensity at Freezing

39°

32°

Freezing/MeltingFreezing/Melting

• Freezing turns a liquid into a solid.

• Melting turns a solid into a liquid.

Condensation and EvaporationCondensation and Evaporation

• Condensation is a gas changing into a liquid.

• Liquids evaporate into gases.

Sublimation and FrostSublimation and Frost

• Sublimation is a solid changing into a gas.

• A gas becomes solid through deposition.

Water Cycle (Hydrologic Cycle)Water Cycle (Hydrologic Cycle)

Water is constantly being cycled between the atmosphere, the ocean and land. This cycling is a very important process that helps sustain life on Earth. 

Each part of the cycle drives the

other parts.

EvaporationPrecipitation

Condensation

Infiltration

EvaporationEvaporation

Evaporation is the process where a liquid changes from its liquid state to a gaseous state.

Approximately 80% of all evaporation is from the oceans, with the remaining 20% coming from inland water and vegetation.

Only about 10 percent of the water evaporated from the oceans is transported over land and falls as precipitation. Once evaporated, a water molecule spends about 10 days in the air.

HumidityHumidity

Most of the time, you can't see it, but the air contains a lot of water.  The amount of water in the air is called humidity. The atmosphere is the super-highway of the water cycle.

Wind speed: the higher the wind speed, the more evaporation.Temperature: the higher the temperature, the more evaporation.Humidity: the lower the humidity, the more evaporation.

Wind speed: the higher the wind speed, the more evaporation.Temperature: the higher the temperature, the more evaporation.Humidity: the lower the humidity, the more evaporation.

TranspirationTranspiration

Transpiration is the loss of water from the leaves by evaporation; this helps keeps water moving round the plant by sucking water up from the roots.

10% of total evaporation

CondensationCondensation

Condensation is the opposite of evaporation. Condensation occurs when a gas is changed into a liquid.

Cloud FormationCloud Formation

In the United States, there are 40trillion gallons of water above your head on an average day.

Cloud FormationCloud Formation

When the air cools, water vapor condenses into tiny water droplets, which form clouds.

Condensation NucleiCondensation Nuclei

The particles around which water vapor condenses are called condensation nuclei. Some condensation nuclei are smoke, dust, or salt crystals from the ocean.

Three Main IngredientsThree Main Ingredients

• Moisture

• Cooling air

• Condensation Nuclei

• Moisture

• Cooling air

• Condensation Nuclei

What stops a cloud from falling?What stops a cloud from falling?

1 mile in diameter and 300 feet thick

Stratus and CumulusStratus and Cumulus

The word stratus comes from the Latin word that means "to spread out." Stratus clouds are horizontal, layered clouds that stretch out across the sky like a blanket.

The word cumulus comes from the Latin word for a heap or a pile. Cumulus clouds are puffy in appearance. They look like large cotton balls.

Cirrus and NimbusCirrus and Nimbus

The word cirrus comes from the Latin word for a tuft or curl of hair. Cirrus clouds are very wispy and feathery looking.

Nimbus means rain cloud.

Cumulus

Stratus

Cirrus

Cumulonimbus

PrecipitationPrecipitation

When the temperature and atmospheric pressure are right, the small droplets of water in clouds form larger droplets and precipitation occurs.

Cloud Droplet – Rain DropCloud Droplet – Rain Drop

Collisions and Coalescence Collisions and Coalescence

PrecipitationPrecipitation

Rain or Snow?Rain or Snow?

HailHail

Runoff and InfiltrationRunoff and Infiltration

• Once the precipitation hits the ground:– It may become run-off– It may be soaked into the ground (infiltration)

InfiltrationInfiltration

Infiltration is an important process where rain water soaks into the ground. Water that infiltrates the ground becomes groundwater making up an aquifer.

InfiltrationInfiltration

As the water infiltrates through the soil and rock layers, many of the impurities in the water are filtered out. This filtering process helps clean the water.

InfiltrationInfiltration

SlopeSlope

VegetationVegetation

1 2

3

4 5

AquiferAquifer

Aquifer is the term given to a rock unit that will yield water in usable quantities to wells or springs. Aquifers must be both

– Porous– Permeable

Snake River AquiferSnake River Aquifer

How Fast Does It Move?How Fast Does It Move?

More than 300200-300100-200

Idaho Falls

50-100

Craters of the Moon

Less than 50

Twin Falls

Surface RunoffSurface Runoff

If precipitation occurs faster than it can get into the ground, it becomes runoff. Runoff remains on the surface and flows into streams, rivers, and eventually lakes or the ocean.

Surface WaterSurface Water

Any water that travels or is stored on top of the ground. 

If you were a drop of water….If you were a drop of water….

Reservoir Approximate Residence Time

Glaciers 40 years

Seasonal Snow Cover 0.4 years

Soil Moisture 0.2 years

Groundwater: Shallow 200 years

Groundwater: Deep 10,000 years

Lakes 100 years

Rivers 0.04 years

Most Important ElementMost Important Element

Words to RememberWords to Remember

• Evaporation

• Transpiration

• Condensation

• Precipitation

• Surface Runoff

• Infiltration

• Aquifer

If you were a drop of water:If you were a drop of water:

• In a river (surface runoff)– To a lake

• Groundwater• Animal• River• Clouds• Stay in lake

– To groundwater (infiltration)

• Lake• Stays in groundwater• River

– To the ocean• Clouds• Stay in ocean

– To an animal• Soil• Clouds• Stay in animal

– To clouds (evaporation)

• Soil• Glacier• Lake• Ocean• Stay

• In a one hundred year period, an average water molecule spends 98 years in the ocean, 20 months as ice, about two weeks in lakes and rivers, and less than a week in the atmosphere.

• One inch of rain falling on one acre of land is equal to about 27,154 gallons of water. (United States Geological Survey)