Class 10 : Social Science (In English) – Lesson 8. Water Resources

EXPLANATION & SUMMARY

🌍 1. Importance of Water
💧 Water is essential for life — for drinking, farming, industries, energy, and ecology.
🌾 Irrigation → ensures food security.
🏭 Industries → use water for cooling, cleaning, and processing.
⚡ Hydroelectric power → renewable, clean energy.
🐠 Aquatic biodiversity → rivers, lakes, wetlands sustain fish & ecosystems.

🚨 2. Water Scarcity in India
Although India receives 4% of the world’s freshwater, demand is very high.
Causes of scarcity:
👥 Population growth → pressure on resources.
🚜 Agriculture → over-irrigation, water-intensive crops (sugarcane, paddy).
🏭 Industries & urbanisation → contamination + high use.
🌡️ Uneven rainfall & droughts → regional shortages.
🧪 Pollution → industrial effluents, untreated sewage, agro-chemicals.

🗺️ 3. Multi-Purpose River Valley Projects
Designed to use river water for irrigation, drinking water, flood control, hydro power, recreation.
Examples:
🏞️ Bhakra Nangal Dam (Satluj, Himachal–Punjab) → irrigation, HEP.
🏔️ Tehri Dam (Bhagirathi, Uttarakhand) → drinking water + power.
🐘 Sardar Sarovar (Narmada, Gujarat) → water to Rajasthan, Maharashtra.
🌊 Hirakud Dam (Mahanadi, Odisha) → flood control.
Benefits:
🌾 Agricultural productivity boost (Green Revolution).
⚡ Cheap hydroelectricity.
💧 Drinking water supply to towns.
🚢 Inland navigation, tourism, fish breeding.
Problems/criticism:
🏡 Large-scale displacement of tribals.
🐟 Loss of biodiversity (submergence, fish migration blocked).
⚔️ Conflicts between states (e.g., Cauvery).
🌐 Flood/drought mismanagement when water is diverted.

🌊 4. Rainwater Harvesting
Ancient + modern technique to conserve water.
Methods:
🏠 Rooftop collection → channels to tanks.
🏜️ Small earthen dams, check dams, percolation tanks.
🌳 Traditional systems:
Rajasthan → Khadins, Johads, Tankas.
Maharashtra → Bunds.
Himachal → Kuhls (canals).
Meghalaya → Bamboo drip irrigation.
Tamil Nadu → Eris (tanks).
Advantages:
💧 Groundwater recharge.
🚰 Reduce dependence on dams.
🌍 Environment-friendly, cheap.
👥 Community participation.

🌦️ 5. Need for Sustainable Water Management
🌱 Use water judiciously for agriculture.
♻️ Reuse domestic wastewater for gardens/industries.
🚫 Reduce water pollution at source.
🌳 Afforestation → reduces runoff, increases recharge.
🧑‍🤝‍🧑 Encourage people’s movements (like Chipko, Narmada Bachao).
⚡ Promote alternative energy sources (solar, wind) to reduce dam dependence.

📝 Summary
Water is a vital resource for survival, development, and ecology. Despite India’s rich river network and monsoon, the country faces scarcity due to overuse, rising population, industrialisation, pollution, and uneven rainfall.
To address this, multi-purpose river valley projects like Bhakra Nangal, Sardar Sarovar, and Hirakud have been developed, serving irrigation, power, and flood control, but they also caused displacement, ecological loss, and conflicts.
Sustainable water practices are crucial. Rainwater harvesting (Khadins, Tankas, Johads, Bamboo drip irrigation) provides traditional solutions that recharge groundwater and reduce stress on large dams. The future depends on efficient water management, community participation, and balancing human needs with ecosystem health.

⚡ Quick Recap
💧 Water = essential for life, farming, industry, power.
🚨 Scarcity → due to population, agriculture, pollution, uneven rainfall.
🏞️ Multi-purpose projects → irrigation, power, flood control; but displacement + conflicts.
🌊 Rainwater harvesting → traditional + modern methods, groundwater recharge.
🌍 Sustainable management → judicious use, afforestation, pollution control, people’s movements.

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QUESTIONS FROM TEXTBOOK

Question 1. Multiple choice questions
(i) Based on the information given below classify each of the situations as suffering from water scarcity or not suffering from water scarcity:
(a) Region with high annual rainfall.
(b) Region having high annual rainfall and large population.
(c) Region having high annual rainfall but water is highly polluted.
(d) Region having low rainfall and low population.
Answer:
🌧️ (a) Region with high annual rainfall → ❌ Not suffering from scarcity.
👥 (b) High rainfall + large population → ✅ Suffering from scarcity (demand > supply).
🏭 (c) High rainfall but polluted water → ✅ Suffering from scarcity (usable water absent).
🏜️ (d) Low rainfall + low population → ❌ Not suffering from scarcity (demand balanced).

(ii) Which one of the following statements is not an argument in favour of multi-purpose river projects?
(a) Multi-purpose projects bring water to those areas which suffer from water scarcity.
(b) Multi-purpose projects by regulating water flow help to control floods.
(c) Multi-purpose projects lead to large scale displacements and loss of livelihood.
(d) Multi-purpose projects generate electricity for our industries and our homes.
Answer:
🚫 (c) Multi-purpose projects lead to large scale displacements and loss of livelihood.

(iii) Here are some false statements. Identify the mistakes and rewrite them correctly.
(a) Multiplying urban centres with large and dense populations and urban lifestyles have helped in proper utilisation of water resources.
❌ Wrong → ✔️ Multiplying urban centres with large populations have increased misuse and overutilisation of water resources.
(b) Regulating and damming of rivers does not affect the river’s natural flow and its sediment flow.
❌ Wrong → ✔️ Regulating and damming of rivers disturbs natural flow, sediment deposition, and aquatic life.
(c) Today in Rajasthan, the practice of rooftop rainwater harvesting has gained popularity despite high water availability due to the Indira Gandhi Canal.
❌ Wrong → ✔️ Today in Rajasthan, rooftop rainwater harvesting is gaining popularity due to water scarcity in spite of the Indira Gandhi Canal.

Question 2. Answer the following questions in about 30 words.
(i) Explain how water becomes a renewable resource.
Answer:
🌧️ Water follows a hydrological cycle → evaporation, condensation, precipitation.
💧 Rain and snow replenish rivers, lakes, groundwater.
🌍 Hence, water is renewable through natural recycling.

(ii) What is water scarcity and what are its main causes?
Answer:
💧 Water scarcity = when demand exceeds availability of usable freshwater.
🔑 Causes:
👥 Population growth.
🚜 Over-irrigation & water-intensive crops.
🏭 Industrial pollution + untreated sewage.
🌡️ Uneven rainfall & droughts.

(iii) Compare the advantages and disadvantages of multi-purpose river projects.
Answer:
Advantages:
🌾 Irrigation support for agriculture.
⚡ Hydro-power generation.
💧 Drinking water supply.
🛶 Inland navigation & tourism.
Disadvantages:
🏡 Displacement of people.
🐟 Damage to aquatic life & biodiversity.
⚔️ Inter-state disputes over sharing.
🌊 Over-regulation → floods/droughts in downstream areas.

Question 3. Answer the following questions in about 120 words.
(i) Discuss how rainwater harvesting in semi-arid regions of Rajasthan is carried out.
Answer:
🏜️ Rajasthan faces arid climate, sandy soil, scarce rainfall.
🌧️ People developed traditional rainwater harvesting methods:
Khadins → embankments built across fields to store rainwater → moisture for crops.
Johads → small check dams storing water → recharge groundwater.
Tankas → underground tanks in houses to store rooftop rainwater for drinking.
👩‍🌾 These practices ensured self-sufficiency in water before canals.
🌍 Even today, such methods are revived for sustainability.

(ii) Describe how modern adaptations of traditional rainwater harvesting methods are being carried out to conserve and store water.
Answer:
🏠 Rooftop rainwater harvesting → pipes carry rainwater to storage tanks.
🏗️ Percolation pits & recharge wells → enhance groundwater.
🌱 Urban housing societies → mandatory rainwater harvesting systems.
🏞️ Rural areas → check dams, contour bunding, percolation tanks.
🌍 Modern technology blends with traditional wisdom (e.g., tankas, johads).
👉 This ensures long-term water security and reduces overdependence on big dams.

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OTHER IMPORTANT QUESTIONS FOR EXAMS

🔵 Q1. Which of these regions is not likely to face water scarcity?
🟡 Options:
(A) Region with high rainfall but dense population
(B) Region with low rainfall and low population
(C) Region with polluted rivers
(D) Region with intensive agriculture
🟢 Answer: (B) Region with low rainfall and low population

🔵 Q2. Which one is not an argument in favour of multi-purpose river projects?
🟡 Options:
(A) Provide irrigation water
(B) Generate electricity
(C) Lead to large-scale displacement
(D) Help flood control
🟢 Answer: (C) Lead to large-scale displacement

🔵 Q3. Which of these is a traditional rainwater harvesting system of Rajasthan?
🟡 Options:
(A) Johads & Tankas
(B) Bunds & Eris
(C) Bamboo drip irrigation
(D) Kuls
🟢 Answer: (A) Johads & Tankas

🔵 Q4. Which project is built on the river Narmada?
🟡 Options:
(A) Bhakra Nangal
(B) Tehri
(C) Sardar Sarovar
(D) Hirakud
🟢 Answer: (C) Sardar Sarovar

🔵 Q5. Which of the following helps recharge groundwater?
🟡 Options:
(A) Rainwater harvesting
(B) Industrial waste
(C) Over-irrigation
(D) Mining
🟢 Answer: (A) Rainwater harvesting

🔵 Q6. Which Act regulates the use of river valley projects in India?
🟡 Options:
(A) Wildlife Protection Act
(B) Indian Forest Act
(C) Environment Protection Act
(D) No single uniform Act
🟢 Answer: (D) No single uniform Act

🔵 Q7. Hirakud Dam is located on which river?
🟡 Options:
(A) Godavari
(B) Mahanadi
(C) Krishna
(D) Kaveri
🟢 Answer: (B) Mahanadi

🔵 Q8. Which of these is a disadvantage of multipurpose projects?
🟡 Options:
(A) Provide power
(B) Provide irrigation
(C) Displace people
(D) Supply drinking water
🟢 Answer: (C) Displace people

🔵 Q9. Which state is famous for rooftop rainwater harvesting called Tankas?
🟡 Options:
(A) Punjab
(B) Rajasthan
(C) Kerala
(D) Tamil Nadu
🟢 Answer: (B) Rajasthan

🔵 Q10. Which multipurpose project is constructed on the Bhagirathi river?
🟡 Options:
(A) Tehri Dam
(B) Bhakra Nangal
(C) Hirakud
(D) Sardar Sarovar
🟢 Answer: (A) Tehri Dam

🔵 Q11. “Kuls” are traditional water channels in:
🟡 Options:
(A) Rajasthan
(B) Himachal Pradesh
(C) Tamil Nadu
(D) Meghalaya
🟢 Answer: (B) Himachal Pradesh

🔵 Q12. Which is not a cause of water scarcity?
🟡 Options:
(A) Pollution
(B) Over-irrigation
(C) Judicious use of water
(D) Population growth
🟢 Answer: (C) Judicious use of water

🔵 Q13. Bamboo drip irrigation is practiced in:
🟡 Options:
(A) Meghalaya
(B) Odisha
(C) Tamil Nadu
(D) Rajasthan
🟢 Answer: (A) Meghalaya

🔵 Q14. Which river project benefits Gujarat, Maharashtra, and Rajasthan?
🟡 Options:
(A) Hirakud
(B) Tehri
(C) Sardar Sarovar
(D) Bhakra Nangal
🟢 Answer: (C) Sardar Sarovar

🔵 Q15. Which method of irrigation is the most sustainable?
🟡 Options:
(A) Over-irrigation of paddy
(B) Groundwater overuse
(C) Rainwater harvesting
(D) Excessive canal irrigation
🟢 Answer: (C) Rainwater harvesting

🔵 Q16. Which is an economic advantage of multipurpose projects?
🟡 Options:
(A) Loss of fertile soil
(B) Loss of biodiversity
(C) Cheap hydroelectricity
(D) Submergence of villages
🟢 Answer: (C) Cheap hydroelectricity

🔵 Q17. Which state practices Eris (tank irrigation)?
🟡 Options:
(A) Tamil Nadu
(B) Rajasthan
(C) Himachal Pradesh
(D) Assam
🟢 Answer: (A) Tamil Nadu

🔵 Q18. Which factor causes water scarcity even in high rainfall areas?
🟡 Options:
(A) Heavy population pressure
(B) Judicious use of water
(C) Rich aquifers
(D) Dense forests
🟢 Answer: (A) Heavy population pressure

🔵 Q19. Which of the following is a function of multipurpose projects?
🟡 Options:
(A) Irrigation
(B) Flood control
(C) Electricity generation
(D) All of the above
🟢 Answer: (D) All of the above


🔵 Q20. Explain how water is a renewable resource.
🟢 Answer:
🌧️ Water recycles through the hydrological cycle (evaporation → condensation → precipitation).
💧 This continuous cycle renews freshwater supply in rivers, lakes, and groundwater.

🔵 Q21. State two causes of water scarcity.
🟢 Answer:
👥 Rapid population growth.
🚜 Over-irrigation and water-intensive farming (paddy, sugarcane).

🔵 Q22. Mention two traditional rainwater harvesting methods in India.
🟢 Answer:
🏜️ Khadins & Tankas (Rajasthan).
🌳 Kuhls (Himachal Pradesh).

🔵 Q23. Name two advantages of multipurpose river projects.
🟢 Answer:
🌾 Irrigation support for agriculture.
⚡ Generation of cheap hydroelectricity.


🌟 SECTION C — Short Answer (3 marks each)

🔵 Q24. What is water scarcity? Give any two factors responsible.
🟢 Answer:
💧 Water scarcity = when demand for usable freshwater exceeds supply.
Factors:
🏭 Industrial pollution and untreated sewage.
🌡️ Uneven rainfall & drought-prone conditions.

🔵 Q25. Give three disadvantages of multipurpose projects.
🟢 Answer:
🏡 Displacement of people.
🐟 Disturb aquatic ecosystems and fisheries.
⚔️ Interstate disputes over water sharing.

🔵 Q26. How does rainwater harvesting help in water conservation?
🟢 Answer:
💧 Recharges groundwater.
🏠 Provides local supply of drinking water.
🌍 Reduces dependence on large dams.

🔵 Q27. Explain any three modern adaptations of traditional rainwater harvesting.
🟢 Answer:
🏠 Rooftop harvesting with pipes leading to tanks.
🏗️ Percolation pits & recharge wells in cities.
🌱 Contour bunding & check dams in rural areas.

🔵 Q28. List three aims of Sardar Sarovar Project.
🟢 Answer:
💧 Supply water to Rajasthan, Gujarat, Maharashtra.
🌾 Support irrigation for agriculture.
⚡ Generate hydroelectric power.


🌟 SECTION D — Long Answer (5 marks each)

🔵 Q29. Explain five reasons for water scarcity in India.
🟢 Answer:
👥 Population growth → higher demand.
🚜 Over-irrigation → waterlogging & wastage.
🏭 Industrialisation → heavy consumption + pollution.
🌡️ Uneven monsoon & climate change.
💧 Groundwater overuse for agriculture & cities.

🔵 Q30. Compare advantages and disadvantages of multipurpose projects.
🟢 Answer:
Advantages:
🌾 Irrigation to large areas.
⚡ Cheap hydropower supply.
🛶 Navigation & tourism benefits.
💧 Drinking water for towns.
🌍 Flood control in some basins.
Disadvantages:
🏡 Displacement of tribals & locals.
🐟 Ecological imbalance in rivers.
🌐 Conflicts between states.
🪵 Submergence of forests.
⚔️ Over-regulation sometimes worsens floods.

🔵 Q31. Describe rainwater harvesting methods used in semi-arid regions of Rajasthan.
🟢 Answer:
🏜️ Khadins: Embankments across fields to retain rainwater → soil moisture for crops.
💧 Johads: Small earthen check dams → store rainwater, recharge groundwater.
🏠 Tankas: Underground storage tanks in houses → store rooftop rainwater for drinking.
👉 These ensured self-sufficiency in scarce rainfall conditions.

🔵 Q32. Suggest five measures for sustainable water management.
🟢 Answer:
🌱 Judicious use of water in irrigation.
♻️ Reuse domestic wastewater for non-drinking uses.
🚫 Prevent pollution of rivers & lakes.
🌳 Afforestation to enhance recharge.
👥 Community participation in rainwater harvesting.


🌟 SECTION E — Case/Source-Based (4 marks each; 1+1+2)

🔵 Q33. Case: A city suffers from water scarcity despite heavy rainfall.
(i) Which problem is this? (1)
(ii) Give one reason. (1)
(iii) Suggest two solutions. (2)
🟢 Answer:
(i) Water scarcity due to pollution/overuse.
(ii) Heavy demand, contamination of water.
(iii) Rooftop harvesting, strict pollution control.

🔵 Q34. Case: A multipurpose project led to large-scale displacement of tribals.
(i) Identify one such project. (1)
(ii) What is the main issue? (1)
(iii) Suggest two remedies. (2)
🟢 Answer:
(i) Sardar Sarovar / Tehri Dam.
(ii) Displacement & loss of livelihood.
(iii) Proper rehabilitation, alternative livelihood support.

🔵 Q35. Source: “Traditional rainwater harvesting is being revived in Rajasthan.”
(i) Mention one system. (1)
(ii) State one reason for revival. (1)
(iii) Give two benefits. (2)
🟢 Answer:
(i) Tankas/Johads/Khadins.
(ii) Rising water scarcity in desert areas.
(iii) Groundwater recharge, drinking water security.


🌟 SECTION F — Map/Skill-Based (5 marks)

🔵 Q36. On an outline map of India, locate and label any four:
🏞️ Bhakra Nangal Dam (Satluj, Himachal–Punjab)
🏔️ Tehri Dam (Bhagirathi, Uttarakhand)
🌊 Hirakud Dam (Mahanadi, Odisha)
🐘 Sardar Sarovar (Narmada, Gujarat)
🏜️ Area of Tankas (Rajasthan desert region)

🔵 Q37. For visually impaired candidates: List four major multipurpose river valley projects.
🟢 Answer:
Bhakra Nangal (Satluj).
Tehri (Bhagirathi).
Hirakud (Mahanadi).
Sardar Sarovar (Narmada).

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