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.
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