Origin and Formation:
- The Sankosh River originates from the snow-clad Greater Himalayan ranges of Tibet.
- In Bhutan, it is formed by the confluence of two major tributaries, the Mo Chhu and Pho Chhu, near the town of Punakha.
Course Through Bhutan and India:
- The Sankosh River is one of the major rivers of Bhutan and India.
- It flows through Bhutan and then enters India where it joins the Brahmaputra River in the state of Assam.
- The river, known as Mo-chu in Bhutan, travels a distance of 214 km through the country before entering India, where it is called Gangadhar in the plains of Assam beyond Srirampur.
- As the Sankosh River crosses into India, it forms the boundary between the states of Assam and West Bengal and flows for 107 km within India.
Tributaries:
- The Sankosh River has numerous tributaries originating from the Himalayan ranges.
- It is one of the major north bank tributaries of the Brahmaputra River, eventually joining it in the state of Assam.
Catchment Area:
- The Sankosh River has a significant catchment area of 10,345 square kilometers.
Geographical Features and Flooding:
- The Sankosh River traverses various landscapes, including narrow gorges with steep gradients in its upper reaches, and then transitions to flatter slopes as it nears the Indo-Bhutan border.
- The lower reaches of the river, extending to Srirampur, are prone to annual flooding.
Ecological Significance:
- The Sankosh River is one of the major rivers that flows through the Buxa Tiger Reserve, highlighting its ecological importance.