Notes Class 10 Geography Chapter 3 Water Resources

Notes For All Chapters Geography Class 10 CBSE

1. Water as a Renewable Resource

• About three-fourth (¾) of the Earth’s surface is covered with water.
• But only a small portion is fresh water usable for human needs.
• Fresh water comes mainly from:
  • Surface run-off (rivers, lakes, streams)
  • Groundwater
• Water is continuously renewed and recharged through the hydrological cycle.
• Therefore, water is a renewable resource.

2. Water Scarcity and the Need for Water Conservation

Despite being renewable, water scarcity is a big issue.

Causes of Water Scarcity

1. Unequal Access and Overuse

• Over-exploitation of water resources for agriculture, industries, and urban use.
• Unequal distribution among social groups.

2. Population Growth

• Larger population = higher domestic use.
• More food production needed → overuse of irrigation.

3. Agriculture

• Irrigated agriculture is the largest consumer of water.
• Use of wells and tube-wells → falling groundwater levels.
• Need for drought-resistant crops and dry farming.

4. Industrialisation and Urbanisation

• Industries are heavy water users.
• Hydroelectric power (22% of India’s electricity) increases demand.
• Expanding cities → colonies with private groundwater pumps → depletion.

5. Pollution of Water

• Domestic and industrial waste, chemicals, pesticides, fertilizers → contaminate water.
• Even rivers like Ganga and Yamuna are highly polluted.

Government Efforts

• Jal Jeevan Mission (JJM) (2020–21):
  • Aim: Every rural household gets potable piped water.
  • 55 litres per person per day ensured.

Importance of Water Conservation

• Ensures food security
• Safeguards against health hazards
• Protects ecosystems
• Maintains livelihoods and productive activities

3. Multi-purpose River Projects and Integrated Water Resources Management

Ancient Hydraulic Structures

• 1st century B.C.: Sringaverapura (Allahabad) – floodwater harvesting from Ganga.
• Chandragupta Maurya’s time – dams, lakes, irrigation systems.
• 11th century – Bhopal Lake (one of the largest artificial lakes).
• 14th century – Hauz Khas tank (Delhi) by Iltutmish.

Modern Dams

• Definition: Barrier across flowing water creating a reservoir.
• Classified by structure, material, and height.
• Functions:
  • Irrigation
  • Hydroelectricity
  • Domestic & industrial use
  • Flood control
  • Recreation & fish breeding

Multi-purpose Projects

• After Independence → developed as “temples of modern India” (Nehru).
• Example:
  • Bhakra–Nangal Project (Sutlej-Beas basin) – irrigation + hydel power.
  • Hirakud Dam (Mahanadi basin) – water conservation + flood control.

Criticism of Large Dams

1. Environmental issues

• Regulates river flow, reduces sediment flow.
• Sedimentation in reservoirs.
• Poor habitats for aquatic life.
• Submergence of vegetation & soil.

2. Displacement and Social Issues

• Local communities lost land and livelihood.
• Benefits often go to landowners, industries, urban areas.
• Example: Narmada Bachao Andolan, Tehri Dam Andolan.

3. Economic and Ecological Issues

• Change in cropping patterns → water-intensive commercial crops.
• Soil salinisation.
• Increase in gap between rich and poor farmers.
• Conflicts:
  • Farmers vs. cities (e.g., Sabarmati Basin, Gujarat)
  • Inter-state disputes (e.g., Krishna–Godavari dispute).

4. Failure to Control Floods

• Sedimentation reduces capacity → floods worsen.
• Example: Floods in Maharashtra and Gujarat (2006).

5. Other Problems

• Induced earthquakes.
• Water-borne diseases & pests.
• Pollution due to excessive water use.

4. Rainwater Harvesting

Traditional Systems

• Western Himalayas: diversion channels – guls or kuls.
• Rajasthan: rooftop rainwater harvesting (tankas) for drinking water.
• Bengal: inundation channels.
• Jaisalmer (Rajasthan): khadins.
• Other Rajasthan areas: johads.

Rooftop Rainwater Harvesting

• Water collected from rooftops → pipes → underground tanks.
• Example:
  • Phalodi (Rajasthan): household tankas (room-sized).
  • Gendathur (Karnataka): 200 households harvest ~50,000 litres per year each.

Modern Adaptations

• Tamil Nadu: first state to make rooftop harvesting compulsory.
• Shillong (Meghalaya): 15–25% of water needs from rooftop harvesting.
• Thar Desert: underground tankas + rooms for cooling.

5. Bamboo Drip Irrigation System (Meghalaya)

• 200-year-old traditional system.
• Uses bamboo pipes to transport stream water by gravity.
• Carries water over hundreds of metres.
• Finally delivers water as 20–80 drops per minute directly to plant roots.
• An eco-friendly and efficient technique.

6. Important Movements and Projects

• Narmada Bachao Andolan: against Sardar Sarovar Dam (Gujarat).
• Tehri Dam Andolan: against displacement and environmental damage.
• Sardar Sarovar Project: supplies water to drought-prone areas of Gujarat & Rajasthan.