UPSC MainsGEOLOGY-PAPER-I201115 Marks150 Words
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Q3.

Geomorphic divisions of the Indian subcontinent

How to Approach

This question requires a descriptive answer outlining the major geomorphic divisions of the Indian subcontinent. The approach should be to categorize these divisions – the Himalayas, Indo-Gangetic Plain, Peninsular Plateau, Coastal Plains, and Islands – detailing their formation, characteristics, and significance. A structured answer with clear headings and subheadings will be beneficial. Focus on geological processes and resulting landforms. Mentioning relevant examples will enhance the answer.

Model Answer

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Introduction

The Indian subcontinent exhibits a remarkable diversity of landforms, a result of its complex geological history and ongoing geomorphic processes. These landforms are broadly classified into several major geomorphic divisions, each with unique characteristics and influencing factors. Understanding these divisions is crucial for comprehending the region’s climate, drainage patterns, and resource distribution. The subcontinent’s geomorphology is largely shaped by the collision of the Indian plate with the Eurasian plate, leading to the formation of the Himalayas and subsequent development of other features.

1. The Himalayas

The Himalayas, the youngest and most prominent geomorphic feature, extend for approximately 2,500 km from west to east. They were formed by the collision of the Indian and Eurasian plates, resulting in folding, faulting, and upliftment.

  • Formation: Tectonic activity, primarily during the Cenozoic era.
  • Divisions: Greater Himalayas (Himadri), Lesser Himalayas (Himachal), and Outer Himalayas (Shiwaliks).
  • Characteristics: High peaks, deep valleys, glaciers, and active seismic zones.
  • Significance: Source of major rivers, climate control, biodiversity hotspot.

2. Indo-Gangetic Plain

This vast alluvial plain, formed by the deposition of sediments carried by the Indus, Ganga, and Brahmaputra rivers, stretches across northern India and Pakistan. It is one of the world’s most fertile and densely populated regions.

  • Formation: Sedimentary deposition over millions of years.
  • Divisions: Bhabar, Tarai, Bhangar, and Khadar.
  • Characteristics: Flat terrain, fertile soil, extensive river systems, and prone to flooding.
  • Significance: Agricultural heartland, supports a large population, and crucial for irrigation.

3. Peninsular Plateau

The Peninsular Plateau is a large, stable landmass formed by ancient crystalline and metamorphic rocks. It is bounded by the Himalayas in the north and the coastal plains in the east and west.

  • Formation: Gondwana land breakup and subsequent weathering and erosion.
  • Divisions: Deccan Plateau, Central Highlands, and Eastern Ghats.
  • Characteristics: Tablelands, undulating terrain, river valleys, and rich mineral resources.
  • Significance: Source of major rivers, mineral wealth, and supports diverse ecosystems.

4. Coastal Plains

The coastal plains are narrow strips of land along the Arabian Sea and the Bay of Bengal. They are formed by the deposition of sediments by rivers and marine processes.

  • Western Coastal Plain: Narrower, rocky, and characterized by lagoons and estuaries (e.g., Kerala backwaters).
  • Eastern Coastal Plain: Broader, formed by the deposition of the Ganga, Mahanadi, Godavari, and Krishna rivers, with deltas (e.g., Sundarbans delta).
  • Characteristics: Fertile soil, suitable for agriculture, and important fishing grounds.
  • Significance: Supports a large population, harbors, and tourism.

5. Islands

The Indian subcontinent includes two major island groups: the Andaman and Nicobar Islands in the Bay of Bengal and the Lakshadweep Islands in the Arabian Sea.

  • Andaman and Nicobar Islands: Volcanic in origin, covered with dense forests, and home to diverse flora and fauna.
  • Lakshadweep Islands: Coral in origin, small atolls, and known for their pristine beaches.
  • Characteristics: Tropical climate, rich biodiversity, and unique ecosystems.
  • Significance: Tourism, strategic importance, and biodiversity conservation.
Geomorphic Division Formation Key Characteristics
Himalayas Tectonic Collision High Peaks, Glaciers, Seismic Activity
Indo-Gangetic Plain Alluvial Deposition Fertile Soil, River Systems, Flat Terrain
Peninsular Plateau Ancient Crystalline Rocks Tablelands, Mineral Resources, River Valleys
Coastal Plains Sedimentary Deposition Fertile Soil, Lagoons, Deltas
Islands Volcanic/Coral Origin Tropical Climate, Biodiversity, Beaches

Conclusion

The geomorphic divisions of the Indian subcontinent are a testament to its dynamic geological past and ongoing processes. Each division possesses unique characteristics that influence the region’s climate, resources, and human settlements. Understanding these divisions is vital for sustainable development, disaster management, and effective resource utilization. Continued research and monitoring are crucial to address the challenges posed by climate change and geological hazards in this diverse and complex landscape.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Geomorphology
The scientific study of the origin and evolution of landforms.
Alluvial Plain
A flat landform created from the deposition of sediment carried by rivers and streams.

Key Statistics

Approximately 55% of India’s land area is composed of Peninsular Plateau.

Source: National Geographic Society (Knowledge Cutoff: 2023)

The Indo-Gangetic Plain supports over 40% of India’s population.

Source: Census of India, 2011 (Knowledge Cutoff: 2023)

Examples

Sundarbans Delta

The Sundarbans delta, formed by the confluence of the Ganga and Brahmaputra rivers, is the world’s largest mangrove forest and a UNESCO World Heritage Site. It exemplifies the dynamic nature of coastal plains.

Frequently Asked Questions

How do the Himalayas influence the Indian monsoon?

The Himalayas act as a barrier to cold, dry winds from Central Asia, forcing the moisture-laden monsoon winds to rise and cause rainfall over the Indian subcontinent.

Topics Covered

GeographyPhysical GeographyIndian GeographyLandforms