Dafla Hills, Geography, Topography, Climate & Biodiversity

The Dafla Hills are a low hill range located in Assam and Arunachal Pradesh, forming part of the Eastern Himalayan foothills. They lie between the Brahmaputra Valley and the Assam-Arunachal border and are mainly covered with forests.

Dafla Hills

• The Dafla (Daphla) Hills are a rugged hill range located along the border of Assam and western Arunachal Pradesh in northeastern India. 
• They form part of the eastern Himalayan foothills and rise steeply from the plains, with some peaks reaching great heights. 
• The region is covered with dense forests, rich wildlife, and is home to tribal societies and communities, which have helped preserve its natural environment and traditional way of life due to limited development.

Dafla Hills Geography

• The Dafla Hills are located along the border of western Arunachal Pradesh and Assam, with their southern slopes touching the Brahmaputra Valley plains near Tezpur and North Lakhimpur in Assam.
• They are bounded by the Aka Hills in the west and the Abor Range in the east, forming an important part of the northeastern hill system of India.
• Towards the north, the hills rise into the foothills of the Himalayas, while the main Dafla Hill region lies entirely within Indian territory.
• The area is traditionally inhabited by the Dafla (Nyishi) tribe and consists of extensive forested and rugged terrain.
• The region can be accessed from nearby areas such as the Ziro Valley, which acts as an important entry point to the hills.

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Dafla Hills Topography

• The Dafla Hills have a rugged and uneven landscape with steep slopes, sharp peaks and deep valleys, which has kept the region isolated and difficult to access.
• The hills rise from low foothills to high peaks above 3,000 metres, with the highest point reaching about 3,776 metres, showing strong relief.
• They are part of the eastern Himalayan Region, formed due to folding and uplift during mountain-building movements and the area is seismically active.
• Rivers and streams, especially tributaries of the Subansiri River, have cut deep V-shaped valleys and gorges, making movement across the hills difficult.

Dafla Hills Climate

• The Dafla Hills have a monsoon climate, with hot and humid lower areas and cooler conditions at higher heights.
• They receive heavy rainfall during June-September, while winters are mostly dry.
• Rivers like Ranganadi and Dikrong originate here and flow into the Brahmaputra basin.
• Strong monsoon runoff often causes floods in the Assam plains.

Dafla Hills Biodiversity and Protection

• The Dafla Hills lie in the Eastern Himalayan biodiversity hotspot and have dense forests with bamboo, orchids and evergreen trees; areas like Sessa Orchid Sanctuary are famous for orchids.
• Wildlife includes tigers, Asiatic black bears, capped langurs, leopard cats, and many small mammals, though large animals are rarely seen.
• The region is rich in birds, with around 240 species, including the rare Bugun liocichla found near Eaglenest.
• Poaching and deforestation threaten wildlife, mainly due to traditional hunting and logging activities.
• Pakke Tiger Reserve and government-NGO efforts focus on protection, but community participation and enforcement remain key challenges.