The course shifting tendency of the Kosi river is linked with which physical reason?

Correct answer: Deposition of heavy sediment brought from the Himalayas raises and shallows the river bed, causing the river to change its course

The Kosi carries a very large load of silt, sand and other sediments from the Himalayas into the plains of Bihar. As the gradient becomes gentle in the plains, sediment is deposited on the bed, making it raised and shallow. During floods, the river may breach banks or form a new channel, leading to course shifts. Sea tides reaching the Himalayas are not responsible for this behaviour. Exam tip: remember the Kosi as the ‘Sorrow of Bihar’, associated with heavy sediment load and shifting channels.