Kosi River

The Kosi River is a 720 km long transboundary river that flows through China, Nepal, and India, draining the northern slopes of the Himalayas in Tibet and the southern slopes in Nepal. It is the third-largest tributary of the Ganges by water discharge, and its basin covers an area of approximately 74,500 km2. The river's course has shifted over time, with some studies suggesting a slight eastward shift over the past 200 years, but a review of historical maps revealed a more complex and oscillating pattern. The river's unstable nature is attributed to its passage through the steep and narrow Chatra Gorge, which causes it to build up power and change its channel, leading to flooding in India. The Kosi River catchment covers six geological and climatic belts, ranging in altitude from over 8,000 meters to 95 meters, and includes 36 glaciers and 296 glacier lakes in the Dudh-Koshi sub-basin.learn more on wikipedia