The Water Cycle

The Water CycleEvaporation

Sun heats water

Liquid water changes to gas (vapor)

Water vapor riseswith warm air

Humidity Amount of water

vapor, or moisture in the air

Changes with temperature

Warm air holds more moisture than cold air

Cold AirWarm Air

Measuring Humidity

Hygrometer is used to measure the amount of water vapor in the air.

The Water CycleCondensation

Water vapor cools

Tiny water droplets or ice crystals form

Get bigger and heavier

The Water CyclePrecipitation

Air can’t hold up heavy water

droplets or ice crystals

They begin to fall

The Water Cycle

All the different forms of water that fall from the sky.

PrecipitationThe air temperature determines the form of

precipitation.

Types of PrecipitationRain Liquid Air temperature above 32 degrees FahrenheitSnow Solid Air temperature below 32 degrees FahrenheitHail Solid Formed in clouds Winds carry frozen drops higher Layers of ice are added RepeatsSleet Mixture Air temperature just above freezing

Measuring PrecipitationRain gauge

Open container that collects precipitation

Scale on side of container shows how much has fallen

The Water CycleRunoff

Water that does not soak into the ground

Runs downhill into puddles, streams, rivers, or lakes

Then the whole cycle begins again

Review of the Water Cycle