Assam GK – Complete General Knowledge for Assam Competitive Exams

Assam's geography is anchored by the Brahmaputra and Barak valleys, a dual drainage network that feeds agriculture, transport and floodplains across the state.

• The Brahmaputra traverses roughly 2,900 km across Tibet, India and Bangladesh before entering the Bay of Bengal, covering a total run of about 3,848 km from the Chemayungdung Glacier near Lake Mansarovar.
• Local names change along the course: Tsangpo in Tibet, Siang/Dihang in Arunachal Pradesh and Jamuna in Bangladesh.
• North-bank tributaries such as Subansiri, Ronganadi, Jia Bharali, Dhansiri (North), Manas, Beki, Aie and Senkosh descend with steep slopes, braided channels, boulder beds and flashy floods, while south-bank tributaries like Noadehing, Buridehing, Disang, Dikhow, Dhansiri (South), Kopili, Kulsi, Krishnai and Dudhnoi are flatter with deep meanders and lower silt loads.

Hydroelectric and multipurpose dams across the Brahmaputra basin support power, irrigation and civic water supply for Assam and neighboring Himalayan states.

• Listed projects span Meghalaya, Arunachal Pradesh, Assam, Nagaland, Sikkim and West Bengal, underscoring the shared nature of the basin.
• Subansiri Lower (NHPC) anchors Arunachal Pradesh's cascade, while the Teesta stages power Sikkim and the Dooars.
• Kyrdemkulai, Umtru and Doyang schemes combine hydropower with irrigation and drinking water supply for plateau towns.

Assam is administered through 35 districts, each led by a Deputy Commissioner who doubles as district magistrate and revenue head.

• District offices coordinate law and order with revenue collection, reflecting the dual role of the Deputy Commissioner.
• Recent reorganisations created Biswanath, Hojai, Bajali and Tamulpur districts in 2015 before temporary mergers in 2022 and restorations in 2023.
• Baksa, Chirang, Kokrajhar and Udalguri fall inside the Bodoland Territorial Area Districts (BTAD), while South Salmara-Mankachar guards the Bangladesh frontier.

Assam hosts a rich chain of national parks spanning the Brahmaputra floodplains, Himalayan foothills and the Bodoland region.

• Kaziranga (1,090 sq km) evolved from reserve forest in 1908 to national park in 1974 and tiger reserve in 2007, holding two-thirds of the world's one-horned rhinos and a UNESCO tag since 1985.
• Manas (850 sq km) straddles Chirang and Baksa with bhabar-terai habitats, UNESCO status, Project Tiger reserve (1973) and Rhinoceros reintroduction.
• Dibru-Saikhowa (340 sq km) sits between Brahmaputra, Lohit and Dibru rivers, famous for feral horses and as a biosphere reserve (765 sq km) since 1997.

Assam spans 78,438 sq km between 24°8'N–28°2'N and 89°42'E–96°E, forming the easternmost projection of the Indian Plate as it dives under Eurasia to raise the Himalayas.

• Plate tectonics uplifted sediments of the ancient Tethys geosyncline, making the Himalayas climb roughly 4 cm each year while the Brahmaputra, a palaeo-river older than the range, carves deep gorges to maintain its course.
• The Brahmaputra Valley is 80–100 km wide and nearly 1,000 km long, with the river widening up to 16 km in places; Karbi Anglong and Dima Hasao hills are remnants of the South Indian Plateau system.
• Barak Valley averages 40–50 km in width, separated from the Brahmaputra basin by the Karbi and North Cachar hills and draining westward into Bangladesh.

Assam's soils are nitrogen-rich yet erosion-prone, shaped by riverine alluvium, piedmont fans, hill slopes and lateritic plateaus.

• Alluvial soils dominate the Brahmaputra and Barak plains, support cereals, pulses, oilseeds and plantations, and include younger char-land deposits and older brown loams of upper Assam.
• Piedmont soils occupy the Himalayan foothill bhabar and tarai belts with unassorted detritus grading into saturated sandy-silty zones of tall grasses.
• Hill soils—red sandy and red loamy—line the Assam-Meghalaya border, Karbi plateau and Barail hills; they are deep, acidic and rich in organics but can lack phosphates and lime.

Assam experiences a humid tropical monsoon climate with four clear seasons, intense rainfall gradients and six agro-climatic zones.

Assam notifies 18 wildlife sanctuaries, two proposed reserves and one Ramsar site, forming a state-wide safety net for rhinos, primates, birds and wetlands.

• Sanctuaries range from tiny Garampani (6 sq km) to expansive Marat Longri (451 sq km) and Borail (326 sq km).
• Laokhowa-Burachapori, Pabitora and Sonai Rupai secure rhino, buffalo and tiger habitats adjoining the Brahmaputra.
• Karbi Anglong houses a mosaic of sanctuaries (East Karbi, Nambor, Marat Longri, Nambor-Doigrung, Garampani) that connect to Kaziranga and elephants.