WEEK ONE LESSON

How the Water Cycle works

Rainfall and rivers play very important roles in the Water Cycle, moving all sorts of things across the Earth.

The phases of water

Have you ever looked at the sky and seen a large, fluffy cloud that looked like a rabbit, a flower, or even a car? Clouds come in all shapes and sizes, but they’re all made of the same stuff: water. This is possible because of water’s phase changes. A phase change is when water changes between a solid, a liquid, or a gas.

There are tiny particles that make up water and they’re always moving, like little bees in a hive. When the hive changes temperature, the bees move either faster or slower. The same goes for the tiny particles in water, when water’s temperature changes the particles will go faster or slower. Phase changes happen when water changes temperature.

When it isn’t changing between a solid, a liquid, or a gas it is simply called a phase. Water has three phases, a liquid phase, a solid phase, and a gas phase.

The first phase that we’ll talk about is the liquid phase. This is what we normally think of as water, like rivers and lakes or what you pour in a cup. This water is fluid and takes on the shape of whatever is holding it, such as a glass or bowl or the shape of the river.

The second phase of water is the solid phase. When water gets cold, its tiny particles—just like bees—start to move very slow as well. This is how ice is formed, from really slow particles. Ice is a solid phase of water, along with snow and hail. The phase change from a liquid into a solid is called freezing. On the other hand, when ice gets warm, it goes through another phase change called melting. Melting causes the water particles to move faster, and it changes from a solid to a liquid.

The third, and last phase of water, is the gas phase. An example of this phase is steam, the white smoke you see curling from a pot of water on the stove. We get the gas phase of water when water is warmed up to a really hot temperature. The tiny particles that make up water move really fast when they’re really hot, it’s like a hive of bees swarming.

The gas phase of water is all around us in the air, we usually can’t see it, but when it is in the middle of a phase change it becomes something we can see like steam or a cloud. Water changing from a liquid to a gas is called evaporation. On the other hand, when warm air comes in contact with something cold, water goes through a phase change called condensation. We can see condensation when a soda can is taken out of the fridge. The cold temperature of the soda in the can slows down the tiny particles of water in the air around it. The water goes through a phase change from a gas into a liquid on the side of the can, causing those little beads of water.

This is a very small version of condensation, with water forming on the side of a soda can. A larger version of condensation happens outside of the house, when clouds are formed.

Air is always moving, with warm air rising and cold air sinking, and when the two temperatures come in contact it makes a phase change happen. The tiny particles of water in warm air start to cool the higher they are carried into the air, and when water in a gas phase gets cold it goes through condensation. There’s no soda can in the sky for the water to condense on, so it groups together, and when enough water droplets group together then they become big enough for us to see as clouds.

Sometimes if the cloud is high enough in the sky and in a cold enough temperature, the water droplets that make up the cloud will turn into little ice crystals. When enough ice crystals or droplets group together, they start to get heavy. When the cloud can’t hold the droplets or crystals anymore, they begin to fall from the cloud. Precipitation is any form of water falling from the sky, like rain, snow, or hail.

The Water Cycle

The phases of water are important in determining how water moves through the Water Cycle. There is no single start or end to the Water Cycle. Instead of thinking of it as a straight line, think of the Water Cycle like a bunch of circles with water traveling constantly through them.

We’re going to start our journey through the Water Cycle with a cloud, though this isn’t the only place that the Water Cycle can start. Some clouds are white and fluffy. These clouds don’t have heavy droplets of water so they don’t rain. Other clouds, ones that are grey and dark, have a bunch of heavy droplets just waiting to fall.

Sometimes clouds can be made to rain when they’re pushed higher into the air. This often happens when we come across mountains. The air gets colder the higher up we go, so when a cloud comes across a mountain

and is pushed up along the side the cloud will condense quickly. The water in the gas phase that made up the cloud will condense into its liquid phase and rain down the side of the mountain. Water continues to fall from the cloud as it gets pushed up the mountain, and at the very top where it’s really cold, the rain will turn into snow. The snow that stays at the top of the mountain is called storage, generally any water in its solid phase in nature is a form of storage. This water won’t return to the water cycle until it melts and either runs down the mountainside as a liquid or evaporates back into the air as a gas.

The rain that fell down the side of the mountain collects together and always flows to the lowest point on Earth, the ocean. But often it will be absorbed into the ground like a sponge or evaporated into the air before reaching the ocean. It can go through many different parts of nature, like forests and canyons or beaches and farms. Some of the liquid water will flow over the ground in rivers or smaller streams, this water is called surface runoff. Surface runoff is open to the air and often gets filled with rocks, dirt, and anything the river runs past.

Liquid water can also get into the soil and travel through the ground, moving through tiny pockets of air between soil particles in what’s called groundwater flow. Groundwater flow can’t carry rocks and other large things, but it can carry other liquids that get into the soil such as the soda someone pours on the grass or fertilizer from farm fields.

If the water is not evaporated or taken up by plants, both groundwater flow and surface runoff eventually make their way to a water source such as a lake or an ocean, where they are largely stored with the rest of the liquid water. When the ocean is warm enough, some of the liquid water will go through a phase change and evaporate back into a gas. The water in the air can then form a cloud again and begin the Water Cycle all over again, raining back down on the land.

WEEK ONE QUESTIONNAIRE

Please match the word with the definition. One word goes with one definition. Use capital letters.

Definitions:

1. _____ When water changes between a solid, a liquid, or a gas.

2. _____ When water changes from a liquid to a solid.

3. _____ When water changes from a liquid to a gas.

4. _____ When water is a solid, a liquid, or a gas.

5. _____ When water changes from a solid to a liquid.

6. _____ When water changes from a gas to a liquid.

7. _____ Water that falls from the sky.

8. _____ Water that stays as a solid.

9. _____ Water that flows underground and moves in little air pockets in the soil.

10. _____ Water that flows over the ground and is open to the air.

Word Bank:

a. Surface runoff

b. Storage

c. Groundwater flow

d. Evaporation

e. Freezing

f. Melting

g. Condensation

h. Precipitation

i. Phase

j. Phase changes

WEEK TWO LESSON

Water Cycle Summary

Last week we learned about the Water Cycle and how it moves around the Earth. Water has three phases, a gas phase, a liquid phase, and a solid phase. It travels through these phases when falling from clouds, running along the ground to the ocean, and then going back to the sky.

This week we’re going to learn more about how the Water Cycle shapes the Earth and how we affect the Water Cycle.

Canyons

A canyon is a large crack running between two tall walls of rock, sometimes so deep in the earth that you can’t even see the bottom. The Grand Canyon is one of the most famous canyons on earth, it’s a giant maze of rock that was all shaped from a single river. Rivers can shape the ground because the water running over it picks up bits of dirt and rock and carries them away, leaving empty space behind. Over a long amount of time the river carves deeper and deeper into the ground.

Some canyons get so tall that the sun doesn’t reach the bottom, so no plants can grow there. This means that when it rains, it falls down the rocks really fast and pools at the bottom in a flash flood. It’s very dangerous to be in a canyon when it’s stormy, the rivers can run so fast that they can carry boulders!

Forests

Plants slow down the speed of rivers and change their shape. Fallen trees can make water pool in small lakes, while moss covered rocks can make a river run much more slowly. Beavers like to find sticks and make natural dams which stop large rivers and allow only a small amount of water through at a time.

Trees grow around rivers, the water usually moves too fast for a seed to take root, so the shape of a river can change how a forest grows. Sometimes we can even see two different kinds of trees growing on separate sides of the river, so where a river forms there can be two whole different forests with different animals and plants.

Prairies

When rivers are formed in nature they don’t have corners and straight lines. There are two different shapes that a river can make. The first shape is called meandering, which means the river curves like a snake. The second shape is called braided, which looks like braided hair. Braided rivers are, for the most part, formed in deserts and near glaciers, we don’t really see them in Wisconsin. Most of our rivers are meandering.

Prairies are places with a lot of grass and short flowers, with no trees or other big plants. It’s easy to see a river change its shape in a prairie, when there are no plants changing the shape. When rivers change their shape, they sometimes leave behind meander scars. Meander scars are curved indents in the ground where the river once flowed, they happen when the river curves so much that it makes a new shape and cuts off a part of itself.

Terraces

Terraces form over a long period of time, they’re like giant steps in the countryside and are caused from when rivers change their shape. These steps are formed the same way that canyons are, from a river carving into the ground, but instead of the river going deeper into the ground it goes sideways instead.

Because of the different speeds of water in the river—faster by the edges and slower near the bottom—the river cuts into the earth at different speeds. Whatever side is faster will result in the river moving that way, dropping the carved out earth on the other side of the river and building what we call beaches.

Farms

Farmers can’t predict the weather, so to make sure their crops have enough water over the summer they make their own rivers. From a nearby water source, like a lake or a river, a farmer can change the flow so that the water goes to their crops. This way, if there is little rain over the summer, their crops won’t dry out. When a farmer physically brings water to their crops through making their own river, it’s known as irrigation.

It’s important that farmers don’t put irrigated rivers too close to their crops, because chemicals that help the crops grow big and green can also get washed away into the water. These chemicals can make a lot of little green plants, called algae, bloom and these plants take up all the air and leave none for the fish and other animals that live there.

Swamps

Swamps, marshes, and bogs are all places where the soil has been completely filled up with water, so when surface runoff goes across it the water ends up building up into a shallow lake. If there’s no hill to move the water along, the water will stay there until it evaporates or is drained out into some other nearby water source.

Plants that grow in swamps have to grow differently in order to live there since the soil is full of water and their roots can’t get any air. Cypress trees, a type of tree that grows in swamps, have really big bases to store water and their roots grow straight up into the air.

Cities

Areas with a lot of people, like cities and towns, often get flooded streets when it rains. The reason for this is because we have so much pavement—roads and sidewalks—that rain can’t get through, so it all collects and pools on the road. We have giant storm drains on the streets to take care of this, the water on the road falls into the storm drain and flows through a tunnel to a nearby river or lake. If the storm is intense then the water moves really quickly down the streets and cause small floods.

It’s important that the streets and roads are clean, because when these small floods happen they can carry any sort of trash on the ground. This trash will go with the water to whatever source it gets drained into, making a dangerous environment for animals and plants.

Dams

Dams can be both natural and unnatural. We’ve already discussed the natural sort of dam, like a fallen tree or a beaver dam made of a lot of sticks. An unnatural dam is one created by humans, like the Hoover Dam. When humans create dams, there are usually several reasons.

The dam could be built to stop flooding in a lower area, it could be a way to make electricity, or it could be a way to store water for people during long dry seasons over the summer. Dams change the environment, and before building one, the builders have to make sure the dam won’t harm the nearby plants and animals.

Outlets

Outlets are where rivers meet the ocean, normally found around beaches and other sandy areas. The water speeds up really fast, carrying everything that the river was previously moving straight into the open water of the ocean. This is where the surface runoff and groundwater meet up again.

WEEK TWO QUESTIONNAIRE

WORD BANKCondensation Evaporation Melting Freezing Surface runoff

Groundwater flow Precipitation Phase Phase change Storage

Below is an unfinished picture of the Water Cycle. Please finish the picture and label the parts using at least three terms in the word bank.

Please write a short paragraph to describe the picture above, using at least three terms from the word bank.

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List one way that water shapes an environment, and how it does it.

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Some pictures of the design process

I used TinkerCad as it’s a very easy to use program that could easily be incorporated into Tech Ed lessons for elementary students.

This is an overall view of the stream layout and how the nine pieces of the puzzle were interchangeable.

This is a picture of the forest puzzle piece.

The city puzzle piece.

The canyon puzzle piece.

And the swamp puzzle piece. The lower depth of the swamp barriers caused the water to “fill up” the circle, meaning that it took the water longer to run through the swamp. This showed the kids how swamps store water compared to other environments.