Overview
This lecture covers the "Physical Features of India" chapter, detailing India's major physiographic divisions, including their characteristics, formation, and significance.
Major Physiographic Divisions of India
- India is divided into six main physiographic regions: Himalayan Mountains, Northern Plains, Peninsular Plateau, Indian Desert, Coastal Plains, and Islands.
- These divisions result from natural processes and play vital roles in geography, culture, and resources.
The Himalayan Mountains
- The Himalayas are young fold mountains formed by the collision of the Eurasian and Indo-Australian plates.
- The range stretches 2400 km long, width varies from 400 km in Kashmir to 150 km in Arunachal Pradesh.
- Three parallel ranges: Himadri (Greater Himalayas, innermost, highest peaks, snowbound), Himachal (Middle Himalayas, hill stations, valleys), and Shivalik (outermost, made of unconsolidated sediments, lowest in height).
- The Himalayas are further divided into regions: Punjab, Kumaon, Nepal, Assam Himalayas, and Purvanchal (Eastern hills).
- Valleys between ranges are called Duns (e.g., Dehradun) and are areas of settlement.
The Northern Plains
- Located south of the Himalayas, formed by depositional work of rivers from mountains.
- Features include fertile soil, floodplains, oxbow lakes, meanders, distributaries, and doabs (land between two rivers).
- Divided into Punjab Plains, Ganga Plains, and Brahmaputra Plains.
- Further physiographic divisions: Bhabar (pebble-rich, rivers disappear), Terai (marshy, re-emergent streams), Bhangar (old alluvium), Khadar (new, fertile alluvium).
The Peninsular Plateau
- Oldest landmass, made from Gondwanaland, mainly of igneous and metamorphic rocks.
- Two divisions: Central Highlands (north of Narmada, includes Malwa, Bundelkhand, Baghelkhand, Chota Nagpur Plateau) and Deccan Plateau (triangular, south of Narmada, flanked by Western and Eastern Ghats).
- Major rivers (Godavari, Krishna, Kaveri) flow eastwards into the Bay of Bengal due to eastward tilt.
- Western Ghats (continuous, higher, orographic rainfall, Anaimudi peak) and Eastern Ghats (discontinuous, lower, Mahendragiri peak).
The Indian Desert
- Located west of the Aravallis (mainly in Rajasthan).
- Characterized by low rainfall (<150mm/year), high temperatures, and sand dunes (barchans).
- Luni is the only prominent river.
The Coastal Plains
- Western Coastal Plain (narrow, divided into Konkan, Kannada, and Malabar coasts), sandwiched between Western Ghats and Arabian Sea.
- Eastern Coastal Plain (broad, divided into Northern Circar and Coromandel coasts), between Eastern Ghats and Bay of Bengal, forming many river deltas.
The Islands
- Two main groups: Lakshadweep (west, coral islands near Kerala) and Andaman & Nicobar (east, Bay of Bengal, northern Andaman and southern Nicobar, submerged mountain chain, equatorial climate).
Significance of Diversity
- Mountains provide water, minerals, and forests.
- Plains are highly fertile and support intensive agriculture and settlements.
- Plateaus are mineral-rich, aiding industrialization.
- Coasts and islands support fishing, trade, and port activities.
Key Terms & Definitions
- Physiographic Division — Natural regions characterized by unique physical features.
- Doab — Land between two rivers.
- Dun — Valley between mountain ranges.
- Bhabar — Pebble-rich belt at the foothills of the Himalayas.
- Terai — Marshy region south of Bhabar.
- Bhangar — Old alluvial soil.
- Khadar — New, fertile alluvial deposits.
- Oxbow Lake — Crescent-shaped lake formed by meandering rivers.
- Distributary — Channel branching from the main river.
- Tributary — Stream feeding into a larger river.
- Barchan — Crescent-shaped sand dune.
- Coral Island — Island formed from coral deposits.
Action Items / Next Steps
- Review relevant textbook chapters on Physical Features of India.
- Practice map-based questions identifying physiographic regions.
- Prepare short notes on each main division and its features.
- Complete any assigned worksheets or reading on the same topic.