CLASS-VII SCIENCE

NAVODAYA VIDYALAYA SAMITI

CHAPTER-16

Water : A Precious Resource

Prepared by :Meenakshi Patidar

TGT (Science)

JNV, Sonitpur (Assam)

�LEARNING OUTCOMES

1. Identify different forms of water and their availability.
2. Understand the processes involved in recycling of water in nature and changes involved in it.
3. Explain the term ground water and understand the significance of different sources of ground water.
4. To critically analyse the concept of depletion of water; factors and processes which relate it with recharging of ground water.
5. Understand the concept of water management and examine the role of an individual in this.

• IMPORTANCE OF WATER

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• SOURCES OF WATER

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• WORLD WATER DAY

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WATER

IMPORTANCE OF WATER

• Water is natural resource that is vital for both Plant and Animals .
• Water is used for drinking, cooking, bathing, washing, and cleaning.
• Agriculture and Industries.

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SOURCES OF WATER

• Fresh Water- Rain, River, Lake, Pond, Streams, Glaciers, and underground water.
• Saline Water- Ocean and Seas.

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WORLD WATER DAY

• World Water Day is held annually on 22 March as a means of focusing attention on the importance of freshwater and advocating for the sustainable management of freshwater resources.
• This Day is an opportunity to learn more about water related issues, be inspired to tell others and take action to make a difference.

AVAILABILITY OF WATER

71% of earth’s surface is covered with water but only 0.006% of all the water on the earth is available for human consumption.

FORMS OF WATER

Water exists in three states in nature – solid(as ice and snow),liquid (as water) and gas (as water vapour).

WATER CYCLE

GROUND WATER

DEPLETION OF WATER TABLE

• Increasing population
• Increasing industries
• Agricultural activities

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DISTRIBUTION OF WATER

WATER MANAGEMENT

• WATER MANAGEMENT
• USE JUDICIALLY

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• RAIN WATER HARVESTING

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• DRIP IRRIGATION

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USE JUDICIALLY

RAIN WATER HARVESTING

SURFACE RUN-OFF

ROOF TOP

DRIP IRRIGATION

EFFECT OF WATER SCARCITY ON PLANTS

WHAT YOU HAVE LEARNT

• Water is essential for all living beings. There can be no life without it.
• Water exist in three forms: solid, liquid and vapour.
• Though water is maintained by the water cycle, yet there is an acute scarcity of water in many parts of the globe.
• There is an uneven distribution of water. Much of it has resulted from human activities.
• Rapid growth of industries, increasing population, growing irrigation requirements and mismanagement are some of the causes for water shortage.
• We need to be worried about the wastage during the supply of water through pies, the leaking taps in buildings and other places. Unnecessary use of water and overdrawing from groundwater should be avoided. Recharge of water to the ground should be increased.
• The need of the hour is that every individual uses water economically.
• Plants wilt and ultimately dry-up if they are not watered fro a few days.

usefull web links

1. CBSE 7th Science Water A Precious Resource : https://www.youtube.com/watch?v=YErfhiB0o40
2. Water - A precious resource https://www.youtube.com/watch?v=p52sVcnQ_AI
3. Water Scarcity - Water: A Precious Resource https://www.youtube.com/watch?v=pqcWf27Op-I
4. Water Table: https://www.youtube.com/watch?v=rOzDIojofCg
5. CLASS 7 science chap.16"WATER ; A PRECIOUS RESOURCE" ncert https://www.youtube.com/watch?v=nWl43r4l3JI
6. Water: Water Cycle, Forms of Water and Water Conservation - Something Fishy https://www.youtube.com/watch?v=TTkFHO2-jsc
7. The Water Cycle https://www.youtube.com/watch?v=al-do-HGuIk
8. The Sustainable Development Goals Explained: Clean Water and Sanitation https://www.youtube.com/watch?v=LCKsU4bPFOQ
9. WATER our most precious resource https://www.youtube.com/watch?v=VIaw5mCjHPI
10. The Global Water Crisis | How Much Water Do We Really Use Everyday?https://www.youtube.com/watch?v=On9WRrFHVjY

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THANK YOU