EVS / Science

Water Cycle

Class 4 | CBSE / NCERT / ICSE

🎯 Learning Objectives

Describe the four stages of the water cycle: evaporation, condensation, precipitation, and collection.
Identify different sources of water -- rain, rivers, lakes, wells, and oceans.
Explain the difference between fresh water and salt water.
List methods of water conservation and causes of water pollution.

📖 Let Us Begin!

Have you ever wondered where the rain comes from? Or where the water goes after it rains? Water keeps moving in a never-ending journey called the water cycle. The same water that dinosaurs drank millions of years ago is the water we use today!

In India, the monsoon season brings most of our rainfall. Farmers across the country wait eagerly for the rains. Let us explore how water travels, where it is found, and why we must protect it.

The Water Cycle -- Nature's Recycling

The water cycle is the continuous movement of water between the Earth and the sky. It has four main stages:

1. Evaporation: The sun heats the water in rivers, lakes, and oceans. The water turns into water vapour (a gas) and rises up into the air. You cannot see water vapour -- it is invisible. When wet clothes dry on a clothesline, the water evaporates into the air.

2. Condensation: As water vapour rises high into the sky, it cools down. The cool vapour turns back into tiny water droplets. Millions of these droplets come together to form clouds. The fog you see on cold winter mornings in Delhi or Lucknow is also condensation.

3. Precipitation: When clouds become heavy with water droplets, the water falls back to the Earth. This falling water is called precipitation. It can come as rain, hail, or even snow (like in Shimla and Kashmir in winter).

4. Collection: The water that falls collects in rivers, lakes, ponds, and oceans. Some water seeps into the ground and becomes groundwater. This groundwater fills our wells and borewells. Then the cycle starts all over again!

Image needed: The water cycle diagram showing: evaporation (sun heating water), condensation (clouds forming), precipitation (rain falling), collection (rivers/lakes). Arrows showing cycle. Title: "The Water Cycle".
Style: Clear labelled diagram, colourful, child-friendly
Size: 800×500px

Think about it: When your mother boils water for tea and you see steam rising from the kettle, which stage of the water cycle is that?

Sources of Water

Water is found in many places on Earth. These are called sources of water.

Source	Description	Indian Example
Rain	Water falling from clouds; the main source of all fresh water	Monsoon rains from June to September
Rivers	Large flowing bodies of water that carry water to the sea	Ganga, Yamuna, Brahmaputra, Godavari, Kaveri
Lakes	Large bodies of still water surrounded by land	Dal Lake (Kashmir), Chilika Lake (Odisha)
Wells and Borewells	Holes dug deep into the ground to reach groundwater	Common in villages across Rajasthan and Tamil Nadu
Oceans	Huge bodies of salt water covering most of the Earth	Arabian Sea, Bay of Bengal, Indian Ocean

Fresh Water vs Salt Water

Most of the water on Earth (about 97%) is salt water found in oceans and seas. We cannot drink salt water -- it is too salty and can make us sick.

Only about 3% of the Earth's water is fresh water. Fresh water is found in rivers, lakes, glaciers, and underground. This is the water we drink, cook with, and use for farming. Because fresh water is so little, we must use it carefully.

Think about it: If you filled 100 glasses with all the water on Earth, only 3 glasses would be fresh water. How important is it to save water?

Water Conservation -- Saving Every Drop

India faces water shortage in many areas, especially during summer. Here are ways we can conserve water:

Rainwater harvesting: Collecting rainwater from rooftops in tanks for later use. Many schools in Chennai and Bengaluru do this.
Fix leaking taps: A dripping tap wastes hundreds of litres of water every month.
Use a bucket: Bathing with a bucket and mug saves more water than using a shower.
Reuse water: Water used to wash vegetables can be used to water plants.
Drip irrigation: Farmers can use drip irrigation to water crops drop by drop, saving a lot of water.
Close the tap: Turn off the tap while brushing teeth or soaping hands.

Water Pollution -- Causes and Prevention

Causes of water pollution:

Factories dumping chemical waste into rivers (many factories along the Yamuna and Ganga do this).
Throwing garbage, plastic bags, and sewage into rivers and lakes.
Farmers using too many pesticides and fertilisers that wash into water bodies.
People washing clothes and animals in rivers and ponds.

How to prevent water pollution:

Do not throw waste or plastic into rivers, lakes, or drains.
Factories must treat their waste water before releasing it.
Use natural fertilisers instead of chemical ones.
Support clean river projects like the Namami Gange Programme.

Think about it: What would happen to the fish and other animals if we keep polluting our rivers?

📝 Key Words

Word	Meaning
Water cycle	The continuous movement of water between the Earth and the atmosphere
Evaporation	Water changing from liquid to water vapour (gas) due to heat
Condensation	Water vapour cooling and turning back into tiny water droplets
Precipitation	Water falling from clouds as rain, hail, or snow
Groundwater	Water stored under the ground in soil and rocks
Fresh water	Water that is not salty; found in rivers, lakes, and underground
Water pollution	Making water dirty and unsafe by adding harmful substances

⭐ Key Points to Remember

The water cycle has four stages: evaporation, condensation, precipitation, and collection.
Sources of water include rain, rivers, lakes, wells, and oceans.
Only 3% of Earth's water is fresh water -- we must use it wisely.
Water conservation methods: rainwater harvesting, fixing leaks, using buckets, reusing water.
Water pollution is caused by factory waste, garbage, sewage, and pesticides.
We can prevent pollution by not dumping waste and by treating factory water.

Finished learning? Now test what you know!

🎯 Quick Quiz — Test Yourself!

Answer these 8 questions about the water cycle. Read each one carefully and pick the best answer!

Score: 0 / 8

1. How many stages does the water cycle have?

The water cycle has four stages: evaporation, condensation, precipitation, and collection.

2. When the Sun heats water and it turns into vapour, this is called...

Evaporation is when heat turns water into vapour. It is the first stage of the water cycle.

3. When water vapour cools and forms clouds, this is called...

Condensation is when water vapour cools and forms clouds.

4. When water falls from the clouds as rain or snow, this is called...

Precipitation is when water falls from the clouds as rain, snow, or hail.

5. About how much of the Earth's water is fresh water?

Only about 3% of the Earth's water is fresh water, so we must use it wisely.

6. Which is a way to conserve (save) water?

We save water by rainwater harvesting, fixing leaks, using buckets, and reusing water.

7. Which of these causes water pollution?

Water pollution is caused by factory waste, garbage, sewage, and pesticides.

8. Name any ONE stage of the water cycle.

The four stages are evaporation, condensation, precipitation, and collection.

✏️ Practice Questions

A. Fill in the Blanks

1. When the sun heats water and it turns into vapour, it is called .

2. Water vapour cools and forms tiny droplets in a process called .

3. Water falling from clouds as rain or snow is called .

4. About % of Earth's water is salt water found in oceans.

5. Collecting rainwater from rooftops is called .

B. Multiple Choice Questions

1. Which is the correct order of the water cycle?

(a) Condensation, Evaporation, Collection, Precipitation

(b) Evaporation, Condensation, Precipitation, Collection

2. Which of these is a source of fresh water?

(a) Arabian Sea(b) Indian Ocean(c) River Ganga(d) Bay of Bengal

3. Which of these causes water pollution?

(a) Planting trees(b) Rainwater harvesting(c) Dumping factory waste in rivers

C. Short Answer Questions

1. Name the four stages of the water cycle.

2. Write two differences between fresh water and salt water.

3. List three ways to save water at home.

🎨 Think and Do -- Fun Activity

Make a Water Cycle in a Bag: Take a clear plastic zip-lock bag. Pour a small amount of water into it and add a drop of blue ink. Seal the bag tightly and tape it to a sunny window. Over a few hours, watch what happens!

Draw what you observe in the boxes below and label each stage of the water cycle:

After 1 Hour	After 3 Hours	After 5 Hours	Stage Name

Want to review the lesson again?

🎯 Learning Objectives

Describe the four stages of the water cycle: evaporation, condensation, precipitation, and collection.
Identify different sources of water -- rain, rivers, lakes, wells, and oceans.
Explain the difference between fresh water and salt water.
List methods of water conservation and causes of water pollution.

📖 Let Us Begin!

In India, the monsoon season brings most of our rainfall. Farmers across the country wait eagerly for the rains.

The Water Cycle -- Nature's Recycling

The water cycle is the continuous movement of water between the Earth and the sky. It has four main stages:

1. Evaporation: The sun heats water in rivers, lakes, and oceans. Water turns into water vapour and rises up into the air.

2. Condensation: Water vapour rises high, cools down, and turns back into tiny water droplets that form clouds.

3. Precipitation: When clouds become heavy, water falls back to Earth as rain, hail, or snow.

4. Collection: Water collects in rivers, lakes, ponds, and oceans. Some seeps into the ground as groundwater. The cycle starts again!

[Image: The water cycle diagram showing evaporation, condensation, precipitation, and collection with arrows showing the cycle. Title: "The Water Cycle"]

Think about it: When your mother boils water for tea and you see steam rising from the kettle, which stage of the water cycle is that?

Sources of Water

Source	Description	Indian Example
Rain	Water falling from clouds; main source of fresh water	Monsoon rains (June–September)
Rivers	Large flowing bodies of water	Ganga, Yamuna, Brahmaputra, Godavari, Kaveri
Lakes	Large bodies of still water surrounded by land	Dal Lake (Kashmir), Chilika Lake (Odisha)
Wells and Borewells	Holes dug deep to reach groundwater	Common in Rajasthan and Tamil Nadu
Oceans	Huge bodies of salt water	Arabian Sea, Bay of Bengal, Indian Ocean

Fresh Water vs Salt Water

Most water on Earth (about 97%) is salt water in oceans. Only about 3% is fresh water found in rivers, lakes, glaciers, and underground. Fresh water is what we drink, cook with, and use for farming. We must use it carefully.

If you filled 100 glasses with all the water on Earth, only 3 glasses would be fresh water!

Water Conservation -- Saving Every Drop

Rainwater harvesting: Collecting rainwater from rooftops in tanks for later use.
Fix leaking taps: A dripping tap wastes hundreds of litres every month.
Use a bucket: Bathing with a bucket and mug saves more water than a shower.
Reuse water: Water used to wash vegetables can water plants.
Drip irrigation: Farmers water crops drop by drop, saving a lot of water.
Close the tap: Turn off the tap while brushing teeth or soaping hands.

Water Pollution -- Causes and Prevention

Causes:

Factories dumping chemical waste into rivers.
Throwing garbage, plastic bags, and sewage into water bodies.
Farmers using too many pesticides and fertilisers.
People washing clothes and animals in rivers and ponds.

Prevention:

Do not throw waste or plastic into rivers, lakes, or drains.
Factories must treat waste water before releasing it.
Use natural fertilisers instead of chemical ones.
Support clean river projects like the Namami Gange Programme.

What would happen to fish and other animals if we keep polluting our rivers?

📝 Key Words

Word	Meaning
Water cycle	The continuous movement of water between Earth and the atmosphere
Evaporation	Water changing from liquid to water vapour due to heat
Condensation	Water vapour cooling and turning back into tiny water droplets
Precipitation	Water falling from clouds as rain, hail, or snow
Groundwater	Water stored under the ground in soil and rocks
Fresh water	Water that is not salty; found in rivers, lakes, and underground
Water pollution	Making water dirty and unsafe by adding harmful substances

⭐ Key Points to Remember

The water cycle has four stages: evaporation, condensation, precipitation, and collection.
Sources of water include rain, rivers, lakes, wells, and oceans.
Only 3% of Earth's water is fresh water -- we must use it wisely.
Water conservation methods: rainwater harvesting, fixing leaks, using buckets, reusing water.
Water pollution is caused by factory waste, garbage, sewage, and pesticides.
We can prevent pollution by not dumping waste and by treating factory water.

A. Fill in the Blanks

1. When the sun heats water and it turns into vapour, it is called .

2. Water vapour cools and forms tiny droplets in a process called .

3. Water falling from clouds as rain or snow is called .

4. About % of Earth's water is salt water found in oceans.

5. Collecting rainwater from rooftops is called .

B. Multiple Choice Questions

1. Which is the correct order of the water cycle?

(a) Condensation, Evaporation, Collection, Precipitation

(b) Evaporation, Condensation, Precipitation, Collection

2. Which of these is a source of fresh water?

(a) Arabian Sea(b) Indian Ocean(c) River Ganga(d) Bay of Bengal

3. Which of these causes water pollution?

(a) Planting trees(b) Rainwater harvesting(c) Dumping factory waste in rivers

C. Short Answer Questions

1. Name the four stages of the water cycle.

2. Write two differences between fresh water and salt water.

3. List three ways to save water at home.

🎨 Think and Do -- Fun Activity

Draw what you observe and label each stage of the water cycle:

After 1 Hour	After 3 Hours	After 5 Hours	Stage Name

You are viewing the worksheet layout. Click Print to save as PDF or print on A4 paper.

Water Cycle

🎯 Learning Objectives

📖 Let Us Begin!

The Water Cycle -- Nature's Recycling

Sources of Water

Fresh Water vs Salt Water

Water Conservation -- Saving Every Drop

Water Pollution -- Causes and Prevention

📝 Key Words

🎯 Quick Quiz — Test Yourself!

✏️ Practice Questions

Water Cycle

Water Cycle (continued)

Water Cycle — Practice Questions