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Purvanchal Hills


The Purvanchal Hills are an eastern extension of the Himalayan system, bending southward from Arunachal Pradesh along the Indo-Myanmar border. They include a series of discontinuous hill ranges such as the Patkai Bum, Naga Hills, Manipur Hills, Mizo (Lushai) Hills, Barail Range, and the Meghalaya Plateau (Khasi, Jaintia, and Garo Hills).

They are geologically young fold mountains (Tertiary period) made of sedimentary rocks (sandstone, shale, siltstone). Their structure is the result of the collision of the Indian and Eurasian Plates, which uplifted the Himalayan orogeny. Unlike the snow-clad Greater Himalayas, these hills are moderate in elevation (600–3000 m), with dense forests, heavy rainfall, and humid climate.

1. Barail Range

  • Location: Separates the Brahmaputra Valley (north) and Barak Valley (south) in Assam.

  • Geomorphology: Tertiary folded ranges with elongated ridges and valleys.

  • Drainage: Acts as a watershed between the Barak River and the Brahmaputra River.

  • Vegetation: Tropical evergreen and semi-evergreen forests.

  • Tourism: Haflong (Assam's only hill station), known as the Switzerland of the East.

  • Economy: Bamboo products, horticulture, shifting cultivation (jhum).

2. Patkai Bum

  • Location: Along the Indo-Myanmar border, east of Nagaland and Arunachal Pradesh.

  • Geology: Formed of volcanic rocks with sediments; folded Tertiary formations.

  • Elevation: Average height 1500–2000 m.

  • Drainage: Numerous rain-fed streams feeding into the Brahmaputra and Chindwin rivers.

  • Climate: Receives very heavy monsoonal rainfall; dense evergreen forest cover.

  • Tourism: Tribal cultural circuits, unexplored trekking routes, and wildlife.

  • Strategic importance: International boundary hills between India and Myanmar.

3. Naga Hills

  • Location: Predominantly in Nagaland, stretching into northern Myanmar.

  • Highest Peak: Saramati (3,841 m).

  • Geology: Strongly folded sedimentary rocks (sandstone, shale).

  • Relief: Rugged, steep slopes, and deep valleys.

  • Drainage: Dhansiri and Doyang rivers, tributaries of Brahmaputra.

  • Vegetation: Dense tropical rainforests, bamboo, and medicinal plants.

  • Tourism: Kohima (capital), Hornbill Festival, Dzukou Valley trekking.

  • Culture: Home to Naga tribes with distinct traditions.

4. Garo Hills

  • Location: Western Meghalaya Plateau.

  • Geology: Very old rocks of the Precambrian era (gneiss, granite).

  • Elevation: 400–1500 m; Nokrek Peak (1515 m).

  • Vegetation: Subtropical forests, citrus fruits, and betel nut.

  • Tourism: Nokrek National Park (UNESCO Biosphere Reserve), limestone caves, waterfalls.

  • Culture: Matrilineal society (Garo tribe).

  • Drainage: Simsang and other short rivers draining into Brahmaputra.

5. Khasi Hills

  • Location: Central Meghalaya Plateau.

  • Highest Peak: Shillong Peak (1961 m).

  • Geology: Precambrian rocks with coal, limestone, uranium deposits.

  • Climate: Extremely high rainfall due to monsoon funneling effect; Mawsynram and Cherrapunji are among the wettest places on Earth.

  • Tourism: Shillong (Scotland of the East), living root bridges, waterfalls.

  • Vegetation: Evergreen forests, pine groves.

  • Drainage: Short, swift rivers flowing north into Brahmaputra.

6. Mizo Hills (Lushai Hills)

  • Location: Mizoram, forming southern Purvanchal extension.

  • Highest Peak: Phawngpui (Blue Mountain, 2,157 m).

  • Geology: Folded ridges and valleys, sedimentary rocks.

  • Relief: Parallel ranges with north–south orientation.

  • Climate: Humid subtropical, heavy monsoonal rainfall.

  • Tourism: Phawngpui National Park, bamboo forests, cultural heritage.

  • Vegetation: Bamboo forests (often affected by Mautam—cyclical flowering of bamboo).

  • Culture: Home to Mizo tribes with rich dance and festivals.

7. Jaintia Hills

  • Location: Eastern Meghalaya Plateau.

  • Elevation: 1200–1500 m.

  • Geology: Rich in limestone and coal deposits.

  • Geomorphology: Karst landscape with extensive caves (Krem Mawmluh, Krem Liat Prah—the longest cave in India).

  • Tourism: Caves, waterfalls, sacred groves.

  • Drainage: Rivers like Myntdu flow into Bangladesh plains.

8. Manipur Hills

  • Location: Surrounding the Imphal Valley in Manipur.

  • Elevation: 800–2000 m.

  • Geology: Sedimentary rocks with steep folded structures.

  • Relief: Saucer-shaped Imphal Valley encircled by hills.

  • Drainage: Rivers like Barak, Manipur River system.

  • Tourism: Loktak Lake (largest freshwater lake in NE India, with floating phumdis), Keibul Lamjao National Park (home of endangered Sangai deer).

  • Culture: Rich tribal diversity with unique traditions.

Geographical Concepts & Features

Geological Setting

  • These ranges belong to the Tertiary fold mountain system (young, unstable).

  • Composition: sandstone, shale, siltstone (sedimentary rocks).

  • Meghalaya Plateau: ancient block of the Peninsular shield, separated from Chotanagpur Plateau by Garo-Rajmahal Gap.

Drainage

  • Rivers: Barak, Dhansiri, Doyang, Kopili, Simsang.

  • Act as watersheds between Brahmaputra Basin and Barak Basin.

Vegetation

  • Tropical evergreen and semi-evergreen forests.

  • Bamboo, citrus fruits, orchids, and sacred groves.

Climate

  • Humid tropical with heavy monsoonal rainfall.

  • Cherrapunji and Mawsynram: rainfall >11,000 mm annually.


Tourism Potential

  • Adventure Tourism: Trekking (Dzukou Valley, Phawngpui).

  • Eco-Tourism: Caves (Meghalaya), Loktak Lake.

  • Cultural Tourism: Tribal festivals (Hornbill, Mizo festivals, Khasi heritage).

The Purvanchal Hills represent a unique geographical entity, distinct from the Greater Himalayas, with:

  • Young folded ranges (Tertiary origin).

  • Moderate heights (600–3000 m).

  • Heavy monsoonal rainfall, lush forests, and biodiversity.

  • Tourist attractions like Shillong, Loktak Lake, Haflong, Phawngpui, Cherrapunji.

  • Economic activities: shifting cultivation, forestry, coal and limestone mining.

  • Cultural significance: Tribal societies with unique traditions.


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