The Water Cycle

Evaporation, Condensation & Precipitation







I’m water, I make the planet blue,
From the seas to the clouds, boy I stay on the move.
Then I fall out the sky on you,
Then I roll to the sea and the cycle repeats.


First off for what it's worth,
There is just a fixed amount of water on the Earth.
And it's trapped in a cycle moving back and forth,
Between the Earth and the atmosphere, of course.
'Cause all water's been here for like billions of years,
And the sun makes the cycle move, you hear?
It makes water on the surface of the Earth evaporate,
What happens next—well, you'll have to wait!
The sun's heat turns water into steam or vapor,
Which rises in the sky and cools off to make a
Droplet which will combine to form clouds,
This is called condensation, NOW—
The clouds fill with moisture and get too heavy,
They turn dark—here's precipitation, ready—
The water falls back to the Earth's surface,
But not just in the ocean where you get to surf it.
Depending on the temperature it could be
Either rain, hail, snow or sleet.
Next time you look up and see clouds about to burst,
Just know that's the way the that the water cycle works.

I’m water, I make the planet blue,
From the seas to the clouds, boy I stay on the move.
Then I fall out the sky on you,
Then I roll to the sea and the cycle repeats.


Now, when water falls down,
Sometimes it is absorbed or taken in the ground.
It becomes ground water, waiting to be found,
Under your feet there’s water way down all around.
And it can appear in all kinds of things,
Like deep in a well or in natural springs.
But if the rain falls fast and long, then,
The ground can't absorb it all and,
Look at the ground, see the water run across?
This excess water is called runoff.
Always running downhill, it wants to be
Ending up in rivers and ponds and streams.
So, next time you're about to take a drink,
That's a great time to stop and think.
That the water went through a cycle to get there,
The same cycle that's been happening for billions of years.

Water is everywhere!


Did you know that your body is more than 72% water? Water also covers more than 70 percent of the Earth. It's found on the surface of our planet in oceans, rivers, lakes and ponds. Ocean water is salt water, while the water in ponds and rivers is fresh water. Nearly all of the Earth's available water is salt water in the ocean. Most fresh water is deep underground in the soil below our feet or frozen in glaciers. Is water important? Well, without water there would be no life on Earth, so you be the judge.

The water cycle is a process that keeps water moving from the Earth to the sky and back again, over and over. How does it work? Heat from the sun makes the water in oceans and lakes evaporate. Liquid water turns into water vapor, like when you boil water. The water vapor rises into the sky and then cools off. It condenses (turns back to water) in the form of clouds. When the clouds get heavy with water droplets, they precipitate. Precipitation is rain, snow, hail or sleet, depending on the temperature. The water returns to the Earth's surface. And the water cycle begins again.

There's a lot of water, but it's not an endless supply.


It seems like water is everywhere and that there's an endless supply of it. But that's not true. The total amount of water on Earth is estimated to be between 1-2 billion cubic kilometers. And this amount is “fixed” or finite, meaning that's all there is. We can't create new water.

That's right. All the water on the planet today has been around for billions of years. This means that the water we use now existed when dinosaurs roamed the Earth. How can this be? Water simply moves between the Earth and its atmosphere over and over again. That's the water cycle.

The sun causes evaporation.


Evaporation is when a liquid turns into a gas. The sun heats up water and turns it into water vapor. Water vapor is a gas that floats into the air. Think about a rain puddle on the street. It's there one day and gone the next. Where'd it go? It evaporated! Evaporated water eventually condenses.

Where does evaporated water go? It rises into the atmosphere, where it eventually condenses. Some of it condenses in the upper atmosphere, forming clouds. A cloud is a collection of condensed water floating in the atmosphere. Once clouds grow heavy with water droplets, the weather “precipitates.” Precipitation is the general term for any type of water falling from the sky, like rain, hail, sleet or snow.

Have you ever gone outside early in the morning and looked at the grass? Sometimes it's covered with little drops of water called dew. This is an example of condensation. Moisture in the air has cooled and condensed in the form of water. Dew forms on leaves, grass, windows and other surfaces when the air is cold enough. When water droplets form on the outside of a cold drink, that's condensation too.

Precipitation


When it rains or snows, we call that precipitation. Precipitation is water released from clouds in the form of rain, freezing rain, sleet, snow or hail. It's how the water from the clouds returns to Earth. The water is often rain, but if the air is cold enough it can freeze and turn to snow.

Groundwater


When it rains, some of the water soaks into the ground. Groundwater is water that's absorbed or taken into the ground. It collects in the rocks and soil beneath the Earth's surface.

Runoff


When it rains so much that all the water can't be absorbed by the ground, runoff is created. Runoff is water that flow across the surface of the land. Runoff carries both pollution and nutrients into our waterways. Think about all of the things that are on our roads and in our yards. Gas and oil from cars, fertilizers and pesticides from our lawns and gardens, waste from our pets—runoff carries all of these things into our rivers and streams.

Most of Earth's water is salt water.


Most of the water on Earth is in the ocean, and it's salt water, so we can't drink it. Most of the freshwater on Earth is frozen in glaciers or deep underground. It may not seem like it, but only a small amount of the planet's freshwater is in streams, lakes and wetlands, where we typically see it.

Water is not readily available everywhere on Earth.


The Egyptians were the first people to record methods for cleaning water. These records date back more than 1,500 years. Egyptians cleaned water by boiling it over a fire, heating it in the sun, or by dipping a heated piece of iron into it. Heating water kills harmful bacteria that might in it. Most Americans are lucky because all we need to do is turn on the faucet to get clean, drinkable water. In some parts of the world, clean drinking water is not always available.
What makes the planet look blue?
Water
What is water trapped in, moving back and forth?
A cycle
Water moves between what two places?
Earth and the atmosphere
How long has water been around?
Billions of years
What happens when heat from the sun turns water into vapor?
Evaporation
What happens when water vapor rises and cools to form droplets?
Condensation
What are four different forms of precipitation?
Rain, hail, sleet, snow
What is the excess water that can't be absorbed by the ground?
Runoff
What is water that is absorbed into the ground?
Ground water
What do water droplets form when they combine?
Clouds

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