THETHE WATERWATER CYCLECYCLE

THE WATER CYCLETHE WATER CYCLE Water moves around Earth in a Water moves around Earth in a perpetual perpetual

cyclecycle. In the atmosphere, clouds are made . In the atmosphere, clouds are made from tiny droplets of water or pieces of ice. from tiny droplets of water or pieces of ice. Precipitation from the clouds falls on the land Precipitation from the clouds falls on the land and into the lakes, rivers, and oceans. Water and into the lakes, rivers, and oceans. Water then then evaporates evaporates back into the air. The pattern back into the air. The pattern of condensation, precipitation, and evaporation of condensation, precipitation, and evaporation is called the is called the water cyclewater cycle. Let’s look at the . Let’s look at the following diagrams of a water cycle.following diagrams of a water cycle.

VOCABULARYVOCABULARY Water cycleWater cycle- - The pattern of water moving between The pattern of water moving between

the air and the ground over and over again.the air and the ground over and over again.

EvaporationEvaporation- - The sun heats up water that is in The sun heats up water that is in lakes, oceans, rivers or on land. The heat energy lakes, oceans, rivers or on land. The heat energy makes the water rise up into the air as an invisible gas makes the water rise up into the air as an invisible gas called water vapor.called water vapor.

CondensationCondensation- - When the water vapor rises into When the water vapor rises into the air, it is cooled. The water vapor turn into tiny the air, it is cooled. The water vapor turn into tiny

droplets. These come together to form clouds.droplets. These come together to form clouds. PrecipitationPrecipitation- - When the water droplets in the When the water droplets in the

clouds get too heavy, they fall to Earth as rain. If it is clouds get too heavy, they fall to Earth as rain. If it is cold enough, these raindrops can become snow, hail cold enough, these raindrops can become snow, hail

or sleet.or sleet.

THE WATER CYCLETHE WATER CYCLE

THE WATER CYCLETHE WATER CYCLE

THE WATER CYCLETHE WATER CYCLE

THE WATER CYCLETHE WATER CYCLE

WATER ON EARTHWATER ON EARTH

The world’s surface is approximately 71% The world’s surface is approximately 71% water. Of that percentage, the oceans hold water. Of that percentage, the oceans hold about 97% of Earth’s water.about 97% of Earth’s water.

The other 3% of Earth’s water is in the form The other 3% of Earth’s water is in the form of lakes, rivers, or glaciers.of lakes, rivers, or glaciers.

Some water seeps into the ground. Some water seeps into the ground. Someday this water might reach the surface Someday this water might reach the surface again by way of an underground spring. This again by way of an underground spring. This can actually take thousands of years to can actually take thousands of years to happen.happen.

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH

WATER ON EARTHWATER ON EARTH RunoffRunoff- Water that runs along the surface of - Water that runs along the surface of

the earth instead of seeping in. This water the earth instead of seeping in. This water goes directly into a larger body of water.goes directly into a larger body of water.

EVAPORATIONEVAPORATION Evaporation puts water into the air.Evaporation puts water into the air. Solar energy changes water into water vapor.Solar energy changes water into water vapor. The water vapor rises into the air.The water vapor rises into the air. Water is constantly evaporating from lakes, rivers, Water is constantly evaporating from lakes, rivers,

oceans, and even glaciers.oceans, and even glaciers. Wind helps evaporation happen even faster.Wind helps evaporation happen even faster. The amount of water in the air at any given time can The amount of water in the air at any given time can

be measured using a psychrometerbe measured using a psychrometer.. A psychrometer measures the amount of humidity in A psychrometer measures the amount of humidity in

the air. It is measured as a percentage of the air.the air. It is measured as a percentage of the air.

PSYCHROMETERPSYCHROMETER

PSYCHROMETERPSYCHROMETER

PRECIPITATION & PRECIPITATION & CONDENSATIONCONDENSATION

Precipitation forms when water vapor cools in the Precipitation forms when water vapor cools in the air.air.

The water vapor The water vapor condenses condenses , or turns back into its , or turns back into its liquid form. This process is known as liquid form. This process is known as condensation. In this process, very small water condensation. In this process, very small water dropsdrops form and group together into clouds. When form and group together into clouds. When the drops get too heavy, rain, snow, or sleet falls the drops get too heavy, rain, snow, or sleet falls out of the cloud as precipitation. The water cycle is out of the cloud as precipitation. The water cycle is said to be balanced because overall, the amount of said to be balanced because overall, the amount of water that evaporates equals the amount of water that evaporates equals the amount of precipitation that falls.precipitation that falls.

SNOWSTORMSNOWSTORM

RAINSTORMRAINSTORM