Sankosh River

Sankosh River UPSC

The Sankosh River is a prominent transboundary river that originates in the snow-clad Greater Himalayan ranges of Tibet and flows through Bhutan and India. This river, known as the Mo Chhu in Bhutan and as the Gangadhar River in the plains of Assam beyond Srirampur, serves as a vital waterway and a natural connector between two nations before joining the mighty Brahmaputra River in Assam.

Origins and Course

The Sankosh River is formed by the confluence of two major tributaries, the Mo Chhu and Pho Chhu, near Punakha, a historic town in Bhutan. It flows for approximately 214 kilometers within Bhutan, carving through the rugged landscapes of the Himalayan region. Upon entering India, the river travels another 107 kilometers before merging with the Brahmaputra River, one of the largest river systems in the world.

As the Sankosh River crosses into India, it serves as a natural boundary between the northeastern state of Assam and the eastern state of West Bengal. Its total catchment area, spread across the two nations, spans an impressive 10,345 square kilometers.

Geographical Features

The river's journey showcases a remarkable diversity of landscapes. In its upper reaches in Bhutan, the Sankosh traverses narrow gorges with steep gradients, creating dramatic scenery typical of high-altitude Himalayan rivers. As it descends toward the Indo-Bhutan border, the terrain gradually flattens, allowing the river to meander through gentler slopes. In its lower reaches, particularly near Srirampur in Assam, the river widens further but becomes prone to annual flooding, a recurring challenge for the communities living along its banks.

Tributaries and Ecosystem

Numerous tributaries originating from the Himalayan ranges feed the Sankosh River, contributing to its robust flow and ecological significance. The river's extensive catchment supports a diverse array of flora and fauna. It plays a crucial role in sustaining the ecosystems of areas it traverses, including the Buxa Tiger Reserve in India, where it nourishes habitats vital for wildlife conservation.

The Buxa Tiger Reserve is home to a variety of species, and the Sankosh serves as an important source of water for the flora and fauna in this protected area, enhancing its ecological importance.

Cultural and Economic Significance

In addition to its ecological importance, the Sankosh River is integral to the livelihoods of the people living in its basin. It supports agriculture, fishing, and transportation, and its fertile floodplains are a critical resource for farming communities. The river's annual floods, while often destructive, also replenish the soil with nutrient-rich silt, enhancing agricultural productivity in the region.