Water Resources Class 10 Notes | Key Concepts Explained

Looking for comprehensive Water Resources notes for Class 10 Geography? This post covers all essential topics, including the distribution of water, water scarcity, and conservation techniques. Our notes are designed to help students understand key concepts and prepare effectively for exams. 

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Water Scarcity and Its Causes

• Definition: Water scarcity occurs due to over-exploitation, excessive use, and unequal access among social groups.
• Occurrence: Even areas with ample water (e.g., cities) face scarcity due to large populations and unequal distribution.
• Causes:
• Growing population increases demand for domestic use and food production.
• Over-exploitation of water for irrigated and agriculture.
• Falling groundwater levels from wells/tube-wells affect availability and food security.
• Solutions: Develop drought-resistant crops and dry farming techniques.

Impact of Industrialization and Urbanization

• Industrial Growth: Post-independence, industries and MNCs pressure freshwater resources.
• Energy Needs: Hydroelectric power for industries adds to water demand.
• Urban Impact: Dense urban populations and lifestyles increase water/energy needs.
• Groundwater Use: Housing societies use private pumping devices, depleting fragile resources.
• Example: Atal Bhujal Yojana targets water-stressed areas in 7 states (e.g., Gujarat, Haryana) to promote conservation.

Water Quality Issues

• Pollution: Domestic/industrial waste, chemicals, pesticides, and fertilizers contaminate water.
• Health Hazard: Polluted water becomes unsafe despite availability.
• Government Response: Jal Jeevan Mission (JJM) aims for potable piped water (55L/person/day) in rural homes.
• Conservation Need: Essential to safeguard health, food security, livelihoods, and ecosystems.

Multi-Purpose River Projects

Hydraulic Structures in Ancient India

• Near Allahabad a town had a sophisticated water harvesting system, which channelised the flood water of the Ganga River. It dates back to 1st century B.C. 
• There are many extensively built dams, lakes and irrigation systems. The most important lake is Sudarshan lake at Junagarh in Gujarat. 
• Bhopal Lake is one of the largest artificial lakes built in the 11th century A.D. 
• Chandragupta Maurya had built several lakes during his rule.
• In the 14th century, the tank in Hauz Khas, Delhi was constructed by Iltutmish for supplying water to the Siri Fort area.

Multi-Purpose Projects

• Dams are referred as Multi-Purpose Projects.
• Dam: A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment.

Uses of dams

·        To impound rivers and rainwater that can be used later to irrigate agricultural fields.

·        For electricity generation.

·        Water supply for domestic and industrial uses.

·        Flood control.

·        Recreation, inland navigation and fish breeding.

Examples: Bhakra Nangal (Sutluj-Beas) for power/irrigation

Hirakud (Mahanadi) for flood control.

• Jawaharlal Nehru proudly proclaimed dams as the temples of modern India because of their potential to integrate development of agriculture and the village economy with rapid industrialisation and growth of the urban economy. (IMPORTANT POINT)

Challenges of Multi-Purpose Projects

• It affects the natural flow of rivers.
• Poor sediment flow which results in excessive sedimentation at the bottom of the reservoir.
• The reservoirs that are created on the floodplains also submerge the existing vegetation and soil leading to its decomposition over a period of time.
• The dams that were constructed to control floods have triggered floods due to sedimentation in the reservoir.
• It was also observed that the multipurpose projects induced earthquakes, caused water-borne diseases and pests and pollution resulting from excessive use of water.
• Irrigation has also changed the cropping pattern of many regions with farmers shifting to water intensive and commercial crops. It leads to the salinisation of the soil.
• People living around the river lose their land and homes.
• It affects the fauna living in the water as they cannot migrate for spawning (laying eggs).

Rainwater Harvesting

·        In hill and mountainous regions, people built diversion channels like the ‘guls’ or ‘kuls’ of the Western Himalayas for agriculture.

·        ‘Rooftop rainwater harvesting’ was commonly practised to store drinking water, particularly in Rajasthan.

·        In the flood plains of Bengal, people developed inundation channels to irrigate their fields.

·        In arid and semi-arid regions, agricultural fields were converted into rain fed storage structures that allowed the water to stand and moisten the soil like the ‘khadins’ in Jaisalmer and ‘Johads’ in other parts of Rajasthan.

·        In the semi-arid and arid regions of Rajasthan, particularly in Bikaner, Phalodi and Barmer, almost all the houses traditionally had underground tanks or tankas for storing drinking water.

In Rajasthan, the rooftop rainwater harvesting is declining because of the availability of plenty of water from the Indira Gandhi Canal which is perennial(water is available throughout the year).

IMPORTANT: Tamil Nadu is the first state in India which has made rooftop rainwater harvesting structure compulsory to all the houses across the state. There are legal provisions to punish the defaulters.

ü  Rainwater, or palar pani, as commonly referred to in some parts of Rajasthan, is considered the purest form of natural water.

Bamboo Drip Irrigation (Meghalaya)

• System: 200-year-old method using bamboo pipes to tap spring water.
• Process:
• 18-20L enters pipes, travels hundreds of meters, delivers 20-80 drops/minute to plants.
• Gravity-driven, with channels and branches for distribution.
• Adaptation: Pipes elevated over roads for uninterrupted flow.

Additional Notes

• Flood Safety:
• Prepare emergency kits (radio, food, water).
• Avoid floodwaters, snakes, and electrical hazards.
• Use boiled water and disinfect surroundings.
• Key Schemes:
• Pradhan Mantri Krishi Sinchaee Yojana: Ensures irrigation access ("har khet ko pani") and efficiency ("per drop more crop").
• Atal Jal: Promotes smart water management in water-stressed areas.
• JJM: Focuses on rural water supply quality and reliability.