Indian Geography: Location, Extent & Physical Features

1. Location and Extent

• Latitudinal Extent: 8°4' N to 37°6' N (Mainland). The mainland extends from Kanyakumari in the south to Indira Col in the north. The southernmost point of the Indian Union is Indira Point (Pigmalion Point) in the Andaman & Nicobar Islands (6°45' N).
• Longitudinal Extent: 68°7' E to 97°25' E. Extends from Ghuar Mota (Gujarat) in the west to Kibithu (Arunachal Pradesh) in the east.
• Tropic of Cancer: (23°30' N) passes almost through the middle of the country, dividing it into two halves. It passes through 8 states: Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura, and Mizoram.
• Standard Meridian: 82°30' E, passing through Mirzapur (UP), is taken as the Standard Time Meridian of India (IST), which is 5.5 hours ahead of GMT. It passes through 5 states: UP, MP, Chhattisgarh, Odisha, and Andhra Pradesh.
• Size: India is the 7th largest country in the world, with an area of 3.28 million sq km (approx. 2.4% of the world's total geographic area).
• Boundaries: Land boundary is about 15,200 km. Coastline (including islands) is 7,516.6 km.
• Neighbours: Pakistan and Afghanistan (North-West), China, Nepal, Bhutan (North), Myanmar, Bangladesh (East). Across the sea: Sri Lanka and Maldives.

2. Physiographic Divisions of India

India is divided into broadly six physical units based on terrain and geological structure:

I. The Northern and Northeastern Mountains (The Himalayas)

• The Himalayas are young fold mountains extending from the Indus gorge in the west to the Brahmaputra gorge in the east (about 2500 km).
• Divisions from North to South:
  • Trans-Himalayas: North of the Greater Himalayas. Ranges include Karakoram, Ladakh, Zaskar, and Kailash. K2 (Godwin Austen, 8611m) in Karakoram is the highest peak of India (in PoK/Gilgit-Baltistan).
  • Greater Himalayas (Himadri): Continuous range, average height 6000m. Contains Mount Everest (8848.86m, Nepal) and Kanchenjunga (8598m, Sikkim - highest undisputed peak in India).
  • Middle/Lesser Himalayas (Himachal): Average height 3700-4500m. Ranges include Pir Panjal (longest), Dhaola Dhar, Mahabharat. Famous for hill stations like Shimla, Mussoorie, Darjeeling, and the Kashmir Valley.
  • Outer Himalayas (Shiwaliks): Southernmost, lowest range (900-1100m). Made of unconsolidated sediments. Valleys between Shiwaliks and Lesser Himalayas are called Duns (e.g., Dehradun).
• Purvanchal (Eastern Hills): Bending sharply to the south beyond the Dihang gorge. Includes Patkai Bum, Naga Hills, Manipur Hills, and Mizo Hills.

II. The Northern Plains

• Formed by the interplay of three major river systems: Indus, Ganga, and Brahmaputra, along with their tributaries.
• Composed of highly fertile alluvial soil.
• Sub-divisions based on relief features:
  • Bhabar: Narrow belt parallel to Shiwaliks where streams deposit heavy pebbles and boulders. Streams disappear here.
  • Terai: South of Bhabar. Streams re-emerge, creating a wet, swampy, marshy region largely covered with thick forests and wildlife.
  • Bhangar: Older alluvium forming terraces above floodplains. Contains calcareous deposits locally known as Kankar.
  • Khadar: Newer, younger deposits of the floodplains. Renewed almost every year, making it highly fertile and ideal for intensive agriculture.

III. The Peninsular Plateau

• A tableland composed of old crystalline, igneous, and metamorphic rocks. Formed by the breaking and drifting of Gondwanaland, making it the oldest landmass of India.
• Divisions:
  • Central Highlands: North of the Narmada river. Bounded by Aravallis in the northwest and Vindhyas in the south. Slopes from west to east. Includes Malwa Plateau, Bundelkhand, Baghelkhand, and Chotanagpur Plateau (rich in minerals).
  • Deccan Plateau: Triangular landmass south of the Narmada. Flanked by the Western Ghats and Eastern Ghats.
    • Western Ghats: Continuous range parallel to the western coast. Higher elevation than Eastern Ghats. Highest peak: Anamudi (2695m) in Kerala. Important passes: Thal Bhor, Pal Ghat.
    • Eastern Ghats: Discontinuous and irregular, highly dissected by east-flowing rivers (Mahanadi, Godavari, Krishna, Cauvery). Highest peak: Jindhagada Peak / Mahendragiri (historical).
    • Deccan Trap: The northwestern part of the plateau, formed by basaltic (volcanic) rocks, giving rise to black soil perfect for cotton cultivation.

IV. The Indian Desert (Thar Desert)

• Lies mostly to the west of the Aravalli hills in Rajasthan.
• undulating sandy plain covered with sand dunes (Barchans).
• Receives very low rainfall (below 150 mm/year). Arid climate with low vegetation cover.
• Luni is the only large river in this region.

V. The Coastal Plains

• The Peninsular plateau is flanked by narrow coastal strips bordered by the Arabian Sea on the west and Bay of Bengal on the east.
• Western Coastal Plain: Narrow plain between Western Ghats and Arabian Sea. Divided into:
  • Konkan Coast (Mumbai to Goa)
  • Kannad Coast (Karnataka)
  • Malabar Coast (Kerala) - Famous for backwaters or 'Kayals' (e.g., Vembanad Lake).
• Eastern Coastal Plain: Wider and level. Formed by large deltas of major east-flowing rivers. Divided into:
  • Northern Circars (North part)
  • Coromandel Coast (South part) - Receives winter rainfall from retreating monsoons.

VI. The Islands

• Andaman and Nicobar Islands: Archipelago in the Bay of Bengal. Erupted from submarine mountains (extension of Arakan Yoma). Ten Degree Channel separates Andaman from Nicobar. Barren Island is India's only active volcano.
• Lakshadweep Islands: In the Arabian Sea, closer to Kerala coast. Entirely made of coral deposits (atolls). Kavaratti is the administrative headquarters.