catching-raindrops-zanzibar.jpg

cloudinary

Catching Raindrops, Zanzibar

condensation.jpg

Condensation

rainstorm-near-the-bahamas.jpg

Rainstorm near The Bahamas

Water moves through our planet in many ways. This is called the 

. Water is found in many places. It is found on land. It is in the oceans and up in the air. Water comes in three forms. It exists as a solid, liquid or 

As ice melts, it turns to liquid. Water in a glass is liquid.

Water vapor is a gas. You cannot see gas. It is in the air around us.

The water cycle is made up of three parts:

 is when a liquid changes to a gas. Liquid water is found in seas, 

. The sun warms up the water and the water turns into gas. It becomes water 

. It goes up into the air. The planet is surrounded by gases. It is called the atmosphere.

Condensation is when gas changes to a liquid. This happens to water vapor in the atmosphere. The gas cools down. It turns into a liquid.

After condensation, liquid or solid water falls to Earth. Precipitation is what falls. Rain and snow are precipitation. This is how water moves from the atmosphere to Earth.

 is in the air. Places on the coast are very humid. There is a lot of water 

 in the atmosphere. Places far away from water, like deserts, are different. They are not humid.

 grow slowly. They can push up mountains. 

National Geographic: Spring Rains Darken Saturn's Moon Titan


The water cycle can change. Glacial retreat is the process in which glaciers melt faster than their ice can be replaced by precipitation. Glacial retreat limits the amount of fresh water available on Earth. We are experiencing the fastest rate of glacial retreat in recorded history.

Newsela

Jeannie Evers, Emdash Editing

Emdash Editing

National Geographic Society

The water cycle describes how water is exchanged (cycled) through Earth's land, ocean, and atmosphere.

Hydrologic Cycle

 describes how water is exchanged or cycled through Earth's land, ocean and atmosphere. Water always exists in all three places, and in many forms — as 

The water cycle is made up of three major parts: evaporation, condensation and precipitation.

Evaporation is the process of a liquid's surface changing to a gas. In the water cycle, liquid water (in the ocean, lakes or rivers) evaporates and becomes water vapor.

 surrounds us, as an important part of the air we breathe. Water 

 the Earth and keep the planet warm enough to maintain life as we know it.

 process is driven by the sun. As the sun interacts with liquid water on the surface of the ocean, the water becomes an invisible gas (water 

Condensation is the process of a gas changing to a liquid. In the water cycle, water vapor in the atmosphere condenses and becomes liquid.

 can happen high in the atmosphere or at ground level. 

 condenses, or becomes more concentrated (dense). Water 

 condenses around tiny particles called 

 is also influenced by the sun. As water 

 cools, it reaches its saturation limit or 

As was the case with evaporation and condensation, precipitation is also a process. Precipitation describes any liquid or solid water that falls to Earth as a result of condensation in the atmosphere. Precipitation includes rain, snow and hail.

Fog is not precipitation. The water in fog does not condense sufficiently to precipitate, or liquefy, and fall to Earth. Fog and mist are a part of the water cycle called suspensions: they are liquid water suspended in the atmosphere.

Precipitation is one of many ways water is cycled from the atmosphere to the Earth or ocean.

Evaporation, condensation and precipitation are important parts of the water cycle. However, they are not the only ones.

, for instance, describes a variety of ways liquid water moves across land. 

 being released from plants and soil. Plants release water 

 is strongly influenced by light, and so is often associated with the sun and the process of 

 and is sometimes used to evaluate the movement of water in the atmosphere.

Through the water cycle, water continually circulates through three states: solid, liquid and vapor.

As ice melts, it turns to liquid. The ocean, lakes, rivers and underground aquifers all hold liquid water.

Water vapor is an invisible gas. Water vapor is not evenly distributed across the atmosphere. Above the ocean, water vapor is much more abundant, making up as much as 4 percent of the air. Above isolated deserts, it can be less than 1 percent.

 conditions of an area, evaluated over a period of time. Two 

Humidity is simply the amount of water vapor in the air. As water vapor is not evenly distributed by the water cycle, some regions experience higher humidity than others. This contributes to radically different climates. Islands or coastal regions, where water vapor makes up more of the atmosphere, are usually much more humid than inland regions, where water vapor is scarcer.

, for example, it absorbs energy and cools the local environment. As water condenses, it releases energy and warms the local environment.

 caused by water are two of the ways the 

, create mountain peaks and leave behind rubble as big as boulders. Yosemite 

, part of Yosemite National Park in the U.S. state of California, is a 

 melted and retreated, leaving liquid pools.

The process of erosion and the movement of runoff also create varied landscapes across the Earth's surface. Erosion is the process by which earth is worn away by liquid water, wind or ice.

. The flow of water can help carve enormous 

 in the U.S. state of Arizona. They can also be carved by 

Reservoirs are simply where water exists at any point in the water cycle. An underground aquifer can store liquid water, for example. The ocean is a reservoir. Ice sheets are reservoirs. The atmosphere itself is a reservoir of water vapor.

 is the amount of time a water molecule spends in one reservoir. For instance, the 

Residence time for water in the Antarctic ice sheet is about 17,000 years. That means that a molecule of water will stay as ice for about that amount of time.

The residence time for water in the ocean is much shorter — about 3,200 years.

The residence time of water in the atmosphere is the shortest of all — about nine days.

Calculating residence time can be an important tool for developers and engineers. Engineers may consult a reservoir's residence time when evaluating how quickly a pollutant will spread through the reservoir, for instance. Residence time may also influence how communities use an aquifer.

 describes how water moves through Earth's land, oceans and atmosphere. Water always exists in all three places, in many forms. It is in 

, oceans and seas. It is also found underground and as a gas in the air and 

Evaporation is when a liquid changes to a gas. In the water cycle, liquid water in the ocean, lakes or rivers evaporates. When it evaporates, it becomes water vapor. Water vapor is an invisible gas.

 is driven by the sun. The sun warms up the water on the surface of the ocean. The molecules that make up water start moving around quickly and spread apart. The liquid water then turns into an invisible gas. 

Condensation is when gas changes to a liquid. In the water cycle, water vapor in the atmosphere condenses. The gas molecules that were once warm and moving apart quickly become cooler and move closer together. This causes the vapor to become liquid. Clouds can form as water vapor condenses.

Precipitation is any liquid or solid water that falls to Earth after condensation happens in the atmosphere. Rain, snow and hail are all precipitation.

Precipitation is how water is cycled from the atmosphere to the Earth.

Through the water cycle, water continually rotates through three states: solid, liquid and vapor.

Ice turns into a liquid when it melts. The ocean, lakes and rivers all hold liquid water, and it is also found underground.

The amount of water vapor in the atmosphere is different across the Earth. There is a lot in the air above the ocean, but there is less in the deserts because there is less water there.

Humidity is the amount of water vapor in the air. Because water vapor is not evenly spread across the atmosphere, some places have higher humidity than others. This is why there are very different climates on Earth. Islands or coastal regions, like Florida or Hawaii, are usually very humid. Water vapor makes up a large part of the atmosphere in these areas. Inland regions with deserts, like Arizona, are usually not humid at all. That is because there is very little water vapor in the atmosphere.

 slowly expand, they can carve away entire 

 and create mountain peaks. They can leave behind rubble as big as boulders. The Matterhorn is a famous mountain peak between Switzerland and Italy. It was created when 

 smashed together and squeezed up the earth between them.

 of the United States and Canada. They were created when an enormous 

 melted and moved back, leaving liquid pools.

 is when water wears away part of the land. For example, the flow of water can help carve enormous 

On Earth, water moves through the land, oceans and air. This is called the 

. Water always exists in all three places, in many forms. It is in 

 is when a liquid changes to a gas. A liquid is something that flows, like water in a 

. It is not hard like a rock. A rock is a solid. In the 

 is a gas that you cannot see. It goes up into the air into the atmosphere. The Earth is surrounded by a 

Evaporation is driven by the sun. The sun warms up the water on the surface of the ocean. The tiny parts that make up water start moving around quickly and spread apart. The water turns into a gas.

Condensation is when gas changes to a liquid. This happens to water vapor in the atmosphere. The tiny parts of water vapor that were once warm and moving apart become cooler and move closer together. This causes the vapor to become liquid. Clouds can form during condensation.

Precipitation is a liquid or solid that falls to Earth. It falls after condensation happens in the atmosphere. Rain and snow are precipitation.

Precipitation is important in the water cycle. It is how water moves from the atmosphere to the Earth or ocean.

 is solid water. It is hard like a rock and does not flow. Most of Earth's 

. They are mainly found in the North and South Poles.

When ice melts it turns into a liquid. The ocean, lakes and rivers hold liquid water, and it is also underground.

The amount of water vapor in the atmosphere is different across Earth. There is a lot of water vapor in the air above the ocean. Very little vapor is above deserts because it is dry.

Humidity is the amount of water vapor in the air. Some places have higher humidity than others. This is why there are very different climates on Earth. Think of islands or coastal areas, like Florida or Hawaii. These places are usually very humid. Water vapor makes up a large part of the atmosphere in these areas. Places with deserts, like Arizona, are not humid at all.

The water cycle also affects the shape of the Earth's surface.

 slowly grow, they can carve away entire 

 can push together and squeeze up the earth between them.

 are found in between the United States and Canada. They were created when 

 carved huge bowls into the land. Then enormous sheets of 

 is when water wears away part of the land. The flow of water can carve huge 

Water moves through Earth on the land, oceans and air. This is called the 

. Water always exists in all three places, in many forms.

. A liquid is not hard like a rock. A rock is a solid. Liquid water is found in the ocean, 

. It is a gas that you cannot see. It goes up into the air. The air around the planet is called the atmosphere.

Evaporation is caused by the sun. The sun warms up the water and the water turns into gas.

Condensation is when gas changes to a liquid. This happens to water vapor in the atmosphere. The gas cools down and it turns into liquid.

After condensation, liquid or solid water falls to Earth. Precipitation is what falls. Rain and snow are precipitation.

Precipitation is important in the water cycle. It is how water moves from the atmosphere back to Earth.

Water comes in many forms and continually changes in the water cycle. Water is in three forms. They are solid, liquid and vapor.

 is solid water. It is hard like a rock. Most of Earth's 

As ice melts, it turns to liquid. The ocean, lakes and rivers hold liquid water.

Water vapor is in the atmosphere. There is a lot of water vapor above the ocean. There is very little in the air above deserts where it is very dry.

 in the atmosphere. Places far away from water are not humid.

The water cycle also affects the land on Earth.

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our 

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

ARTICLE

ARTICLE

Hydrologic Cycle

Hydrologic Cycle

Grades

Subjects

Loading ...

Articles & Profiles

Website

Credits

Media Credits

Editor

Producer

other

Last Updated

User Permissions

Media

Text

Interactives

Related Resources