WATER

Water is essential for all living things. Plantsabsorb water from the soil through their roots.

Aquatic animals and plants live in water andland animals drink water.

People also need water to survive. Our bodiesare approximately 75% water. Fortunately, we

can find water all over the Earth:On land, underground and in the air

Cantabric sea

Atlanctic ocean

Mediterranean sea

When we see the Earth from space, we can seeclearly why it is called the blue planet. About 75%of its surface is covered water. Most of this water

is in the oceans but a lot of it is found in thedifferent bodies of wáter.

Oceans and seas are the largest bodiesof water.

They are made up of salt water

A lake is a body of water that is surroundedby land on all sides.

Lakes can hold fresh water or salt water

A river is a long body of water that flowsinto an ocean, sea or lake

Rivers carry fresh water.

sReservoirs are man-made lakes for storingfreshwater

A dam is built to stopthe river flowing

Ice caps and glaciers are large masses of ice andsnow. They are made up of fresh water.

They are made up of fresh water.

We can also find fresh water underground.In fact, there is much more water under theEarth´s surface than in all its rivers and lakes

Groundwater mainly comes from rain and meltedsnow that is absorbed into the ground. It is stored

in underground layers of rock or earth calledaquifers

Hydrosphere is the word we use to describe allthe water on Earth: on its surface, underground

and in the air.

Water can be found three different states:LIQUID, SOLID and GAS

The water in oceans, lakes, riversand aquifers is in a LIQUID STATE

The water that is in the air(wáter vapour) is in a GAS STATE

The water in glaciers, ice caps and icebergs is in a SOLID STATE

Does water change

When liquid water is heated it changes from a liquid state to a gas state. This

gas is calledwater vapour. This process is called

EVAPORATION

When liquid water is cooled to a very lowtemperature, it changes into ice, which is water in a solid state. This process is

called

FREEZING

Ice is water in a solid state. When it heats up, it changes back into a liquid

state. This process is called

MELTING

When water vapour cools it changes back into a liquid state. This process is

called

CONDENSATION

the water cycle

All the water on the Earth is constantly changing state and moving from one place to another. We

call this the water cycle. The water cycle is continuous because water never stops changing state. There are four stages of the water cycle.

4 stages

1. EVAPORATIONWhen the Sun heats water, the water evaporates, moving up into the atmosphere as water vapour.

2. CONDENSATIONThe water vapour cools and condenses. Drops of liquid water begin to form and join together to

form clouds.

Clouds

3. PRECIPITATIONWhen the clouds cool and become heavy, drops of water

start to fall in the form of precipitation

Rain Snow Hail

5. COLLECTIONThis water collects in rivers, lakes and oceans and is also

absorbed into the ground as groundwater.

Rivers and streams return the water to the oceans and seas

The water cycle starts again.

Revision

The water cycle is a continuous process of:

Water never stopschanging the

state

1. EVAPORATION

2. CONDENSATION

3. PRECIPITATION

4. COLLECTION

THE WATER CYCLE IS A CONTINUOS PROCESS

OF :EvaporationCondensationPrecipitation Collection.

What’s the water cycle?

1. EVAPORATION 2. CONDENSATION

3. PRECIPITATION4. COLLECTION

You already know where we find fresh water on the Earth, but did you know that not all of this

water is drinkable?

We can only drink clean, fresh water. We call this water drinking water. Water from rivers and lakes is NOT drinking water. It contains

bacteria which have to be removed before it is safe to drink

FRESH WATERCAN WE DRINK ALL THE FRESH WATER?

We can only drink clean fresh water.

We call this water drinking water.

NO

Water from rivers and lakes is

non-drinking water

Approximately 2% of the Earth´s water is fresh waterstored in the form of ice in glaciers, icecaps and

icebergs

Only about 1% of the water on our planet can beconsumed by humans, animals and plants. Someof this fresh water goes through treatment plants

to be cleaned and turned into drinking water

Approximately 97% of the Earth´s water is saltwater. We cannot drink this water because too

much salt is bad for our health

We can survive without food for about a monthbut we can only survive for about a week

without water.

DID YOU KNOW?

I have to drink at least 1,5 litres of water

every day

WASTEWATER TREATMENT

We use a lot of water in our daily lives. we shower, wash the dishes, brush our teeth, water

the plants and drink water.

We all create wastewater, so do factories and farms. Before this water rejoins the water cycle, it must pass through a wastewater treatment plant

WASTEWATER TREATMENT PLANT

Treated wastewater is often used in agriculture and industry. Some farmers use it to water their crops. It can also be used to make products such

as paper and cement

Can I drink wastewater?