Meghna(mĕg`nə), river, c.130 mi (210 km) long, formed at the outlet of the Surma valley, NE Bangladesh, by the branches of the Surma River. It flows south, receiving arms of the Ganges and Brahmaputra rivers, to the Bay of Bengal. The Meghna is an important inland waterway, navigable throughout its length by river steamers, although hazardous due to its high speed. In the springtime, at high tide, tidal bores, c.20 ft (6.1 m) high, rush upstream with great destructive force.
(Megna), the eastern arm of the common delta of the Ganges and Brahmaputra rivers in Bangladesh. Formed by the confluence of the Surma River with one of the eastern arms of the Brahmaputra. Length, approximately 240 km. After merging with the delta’s main arm (the Padma), it forms an estuary up to 60 km wide. It is navigable along its entire length. The Meghna is full throughout the year, since the basin is located partially within the Shillong Mountains (the most humid place on earth). The Meghna Valley has been flooded frequently by the tides. On the banks below the city of Chandpur are mangrove forests.