Brahmapootra, Or Burrampooter(" offspring of Brahma"), one of the largest rivers of India, rises in Thibet at the E. extremity of the Himalaya mountains, between lat. 28° and 29° N, and Ion. 97° and 98° E. Here the Ta-luka and Taluding unite and form the Lohit, which, after emerging from the mountain pass in a S. W. direction, assumes the name of Brahmapootra. Near Suddya, in about lat. 27° 50 N and Ion. 95° 30' E., it is joined by the Di-hong and Dibong. The former has been traced through the Himalaya chain to lat. 28° 15 N". and Ion. 95° 10' E., and is thought to be a continuation of the Dzang-bo-tzin or Sanpo, a large river which rises in Thibet N. of that range. After receiving these tributaries, the river flows 75 m. S. W. through Assam, and then diverges into the Boree Lohit and the Dihing. Uniting again after a divided course of 65 m., it flows W. through the district of Goalpara, winds around the W. extremity of the Garrow hills, separates Goalpara and My-munsing from Rungpoor, and, after sending off a branch called the Konaie, which joins it again further down, runs S. E. for 130 m.
It then changes its name for that of Megna, receives part of the waters of the Ganges through the Kirtynassa, and after various windings enters the bay of Bengal by three channels: the Ganges on the W., the Shabazpoor in the centre, and the Hattia on the E. Its total length, from its source to the bay, is about 900 m.; but including the Dzang-bo-tzin, it is about 1,600 m. It is navigable from its mouth to the Dihong by the ordinary vessels of the country, and for some distance further by canoes. Through the last 60 m. of its course, it is from 4 to 5 m. wide, and studded with islands. Its waters are muddy; its banks are mostly covered with marshes and jungles, and are subject to annual inundations. During the season of the overflow, from the middle of June to the middle of September, the level districts of Assam are almost wholly submerged, so that travel is impossible, except on causeways 8 or 10 ft. high. The volume of water discharged by the river at such times is immense. Even in the dry season it is equal to 146,188 cubic feet a second, while under the same circumstances the Ganges discharges only about 80,000.