Water Resources Lecture Notes

Introduction

• Welcome and introduction to the chapter on Water Resources.
• Famous quote: "Water, water everywhere, but not a drop to drink."

Importance of Water

• Water is abundant but its use is crucial.
• Types of water resources: oceans, rivers, lakes, groundwater, and glaciers.
• 97% of earth's water is saline (not suitable for drinking or irrigation).
• Only 3% is freshwater, out of which:
  • 2.3% is locked in polar ice caps.
  • Only 0.7% is accessible as freshwater.

Types of Water Resources

Surface Water

• Water present on the surface: rivers, lakes, rainwater.

Groundwater

• Water collected underground – important for domestic use.
• Aquifer: saturated underground water that can surface naturally.

Conservation of Water

• Emphasis on saving water as a crucial natural resource for survival.
• Reasons for Conservation:
  • Increasing exploitation due to population growth.
  • Major use in agriculture through artificial irrigation methods.

Techniques of Rainwater Harvesting

• Collection and storage techniques to save rainwater.

Methods

1. Rooftop Rainwater Harvesting:
   • Collect rainwater from roofs and store in tanks.
2. Recharge Pits: Divert water into nearby wells or underground reservoirs.

Traditional Techniques

• Historical methods in Indian civilization for rainwater collection.
• Different local names (e.g., Khadin, Johad).
• Importance of storing excess rainwater to prevent evaporation and improve groundwater levels.

Irrigation Techniques

• Importance of Irrigation: Provides necessary water for agriculture, especially in rain-dependent regions.
• Types of Irrigation:
  • Well Irrigation: Simple and cost-effective.
  • Tube Wells: Deeper wells equipped with pumps for better yields.
  • Canal Irrigation: Use of canals to divert water from rivers to fields.
  • Tank Irrigation: Store water in artificial tanks for seasons of low rainfall.
  • Modern Techniques:
    • Drip Irrigation: Efficient method that delivers water directly to the roots.
    • Sprinkler Irrigation: Water is sprayed over the crops simulating rainfall.

Issues and Solutions

• Water conflict due to uneven rainfalls can lead to floods or droughts.
• Importance of understanding local needs and water scarcity issues.
• Need for effective policies and management to protect and conserve water resources.

Conclusion

• Water is vital and limited; understanding conservation methods is necessary.
• Encouraging practices for future generations to ensure sustainable water supply.
• Call to action: Importance of subscribing to educational resources to stay informed and engaged.

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• Key Takeaways:
  • Water conservation is essential due to limited freshwater resources.
  • Various irrigation and rainwater harvesting techniques can help manage water supply effectively.

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• Consider thoughts on water-saving practices used in personal life and community.