Relief Features of North-East India

North-East India, occupying the extreme North-East corner of the country, is largely a mountainous territory with two-thirds of its area occupied by hilly and mountainous terrain. It is like an amphitheatre, surrounded by the Himalayan ranges on the north, the Indo-Myanmar peripheral chain of hills on the east, and the hills of Mizoram and Tripura on the south and opening out to the west in the valleys of the river Brahmaputra and Barak. The region presents an enormous amplitude of relief, with heights ranging from 50 m ASL in Brahmaputra valley to 7,000 m ASL in the Himalayan borderland. The eastern hilly region, characterised by a series of parallel and subparallel north–south-trending ridges and valleys, lies on the Indo-Myanmar plate boundary on the east and is separated from Brahmaputra valley by Naga–Disang thrust on the west. The north–south alignment of low hills continues in Mizoram, lying on the Myanmar border, and in the state of Tripura, which shares its international border with Bangladesh. The western part of Tripura is a plain, drained by the west-flowing streams that join the river Meghna in Bangladesh to find their way to the Bay of Bengal. The region is seismically active, and the plains of Assam suffer frequent and sometimes most intense floods that cause huge loss of life and property.