Chapter-5: Water

These NCERT Class 7 Geography Chapter 5 notes explain the importance of water as a basic necessity for life on Earth. The chapter helps students understand that although Earth is called the blue planet, only a small portion of water is available for human use.

Water introduces the distribution of water on Earth, sources of fresh water, and the continuous water cycle that maintains balance in nature. The chapter also explains important concepts like tides, ocean currents, groundwater, water scarcity and the need for water conservation.

This chapter builds awareness about responsible use of water and sustainable development.

1. Introduction

• Water is essential for all forms of life on Earth.
• Plants, animals and human beings need water to survive.
• Water supports all biological and physical processes.
• Without water, daily life and natural systems cannot function.
• Water is as important for life as blood is for the human body.

2. Distribution of water on Earth

• Earth is called the blue planet, but most water is not usable.
• About 97% of Earth’s water is saline water found in oceans and seas.
• Only 3% of water is fresh water.
• Most fresh water is locked in ice caps and glaciers.
• Rivers and lakes contain only a very small usable amount of water.

3. Sources of fresh water

• Rivers are an important source of fresh water.
• Lakes and ponds store water for daily use.
• Springs provide natural groundwater at the surface.
• Glaciers act as long-term storage of fresh water.
• Rivers like Ganga, Yamuna and Brahmaputra are major sources in India.

4. Water cycle

• The water cycle is the continuous movement of water on Earth.
• Evaporation occurs when the Sun heats water and turns it into vapour.
• Condensation happens when water vapour cools and forms clouds.
• Precipitation occurs as rain, snow or hail.
• Runoff carries water back to rivers, lakes and oceans.

5. Uses of water

• Water is used for drinking, cooking and washing at home.
• Agriculture depends on water for irrigation.
• Animals need water for survival and farming activities.
• Industries use water for production and power generation.
• Waterways and seas are used for transport and trade.

6. Ocean water

• Ocean water is saline because it contains dissolved salts.
• The main salt present is sodium chloride.
• Saline water cannot be used directly for drinking.
• Oceans store the largest amount of water on Earth.
• Despite abundance, ocean water has limited direct human use.

7. Tides

• Tides are the regular rise and fall of ocean water.
• They occur twice a day in most coastal areas.
• Tides are caused by the gravitational pull of the Moon and Sun.
• High tides raise sea water levels near the coast.
• Low tides expose the shoreline and sea floor.

8. Importance of tides

• Tides help ships reach ports safely.
• They assist fishermen in catching fish.
• Tidal movements help clean coastal areas.
• Tides are used to generate tidal energy.
• They support coastal economic activities.

9. Ocean currents

• Ocean currents are continuous movements of ocean water.
• Warm currents move from the equator towards the poles.
• Cold currents flow from polar regions towards the equator.
• Currents influence climate and rainfall patterns.
• They help sailors and ships in navigation.

10. Groundwater

• Groundwater is water stored below the Earth’s surface.
• It is an important source of drinking water.
• Wells, tube wells and hand pumps extract groundwater.
• Overuse leads to a falling water table.
• Excessive extraction causes water scarcity.

11. Water scarcity

• Water scarcity occurs when demand exceeds supply.
• Increasing population raises water consumption.
• Overuse of groundwater worsens the problem.
• Pollution reduces usable fresh water.
• Regions like Rajasthan, Bundelkhand and the Deccan Plateau face shortages.

12. Water conservation

• Fresh water resources are limited on Earth.
• Demand for water is increasing rapidly.
• Rainwater harvesting helps store water.
• Avoiding wastage saves water for the future.
• Protecting rivers and lakes ensures long-term availability.

13. Important keywords

• Fresh water is water fit for human use.
• Saline water contains dissolved salts.
• Water cycle shows continuous movement of water.
• Evaporation, condensation and precipitation are key processes.
• Tides and ocean currents influence oceans and climate.
• Groundwater and water conservation are vital for sustainability.

Understanding NCERT Class 7 Geography Chapter 5 is important to learn how water supports life, agriculture, industry and transport. The chapter clearly explains natural water processes and highlights the serious problem of water scarcity.

The ideas discussed in Water help students develop environmental awareness and responsible behaviour and are highly useful for school examinations and foundation-level preparation.

Continue reading NCERT Class 7 Geography Chapter 6 – Natural Vegetation and Wildlife to understand different types of forests, wildlife diversity and the need for conservation.

FAQs

Q1. How much fresh water is available on Earth?
Only about 3% of Earth’s water is fresh water, and a very small part is directly usable.

Q2. What is the water cycle?
The water cycle is the continuous movement of water through evaporation, condensation, precipitation and runoff.

Q3. What causes tides?
Tides are caused by the gravitational pull of the Moon and the Sun.

Q4. What is groundwater?
Groundwater is water stored below the Earth’s surface and accessed through wells and tube wells.

Q5. Why is this chapter important for exams?
It explains water resources, natural processes and conservation, making it important for school exams and foundation-level preparation.