Drainage Chapter - Class 9 Geography Notes

Introduction

• Drainage: It is the relationship between trees, rivers, and mountains. If you have studied physical features, this chapter is connected to that.
• All geography subjects are interconnected.

Drainage System

• Meaning of Drainage: The river system of an area.
• Drainage Basin: The area where a river and its tributaries receive water.
• Great Rivers:
  • Nile: The world's longest river.
  • Amazon: The largest by water volume.

River System

• Tributary: A river that joins another river.
• Distributary: A part of a river that branches out from the main river.

Drainage Patterns

• Different types of drainage patterns:
  • Dendritic: Like the branches of a tree.
  • Trellis: Between hard and soft rocks.
  • Rectangular: At 90-degree angles.
  • Radial: Outwards from a central point.

Drainage System in India

• Himalayan River System: Indus, Ganga, Brahmaputra.
• Peninsular River System: Narmada, Tapi, Godavari, Krishna, Kaveri.

Indus River System

• Location: Origin in Tibet.
• Features: Flows through Pakistan.

Ganga River System

• Location: Origin in Uttarakhand.
• Features: Irrigates India's most densely populated areas.

Reservoirs and Their Utility

• Reservoirs: Natural water bodies important for agriculture, industry, and drinking water.
• Logic: Reservoirs store and supply water.

Types of Lakes

• Glacial Lakes: Formed by melting ice.
• Oxbow Lakes: Formed by the meandering of rivers.
• Lagoons: Saline water by the sea.

River Pollution and Conservation

• Problems: Industrial waste, urban waste.
• Conservation Plans: National River Conservation Plan, Ganga Action Plan.

Conclusion

• Understand the importance of the drainage system and water.
• It is essential to focus on environmental conservation measures.

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Note: Make sure to read the NCERT textbook.