Irawadi

Irawadi, or IRAWADDY, the principal river of Burma. Its sources are not known with certainty. A favourite origin for it with some authorities was the Sampo (q.v.), the great river of Tibet. But this has been shown in 1878-82 to be the upper waters of the Brahmaputra. In 25° 50' N. lat., a short distance above Bhamo, two arms, the Mali-kha and the Meh-kha, unite to form the river that is undoubtedly the Irawadi of Burma. Those two arms are believed to have their sources in the Namkin or Khanung range, that walls in the Zayul basin on the south; they certainly come from that direction. But General Walker, late of the Indian Trigonometrical Survey, is responsible for the hypothesis, advanced in 1887, that the right-hand or eastern branch, the Meh-kha, is the southward continuation of the Lu-Kiang, which has hitherto been regarded as the upper part of the Salwin; and he also identifies the Lu-Kiang with the Giama-nu-chu or Nu River, which rises in the north of Tibet and has a course, south-easterly, of some 700 miles in that country. From Bhamo the Irawadi has a very sinuous channel, its predominant direction being, however, south. Over this entire stretch (about 700 miles) it is navigable for small boats, in spite of numerous islands and sandbanks that litter and impede its channel, and in spite of two rock-bound defiles through which it passes between Bhamo and Mandalay. A third defile occurs nearly 100 miles above Bhamo. Its waters are muddy and its current generally rapid. Before reaching the sea, in nearly a dozen mouths, in the west of the Bay of Martaban, the river spreads out in a wide delta, 18,000 sq. m. in extent. Of its mouths two only are used by sea-going vessels, the Bassein on the west and the Rangoon on the east. The valley and plain of the Irawadi are very fertile, and grow vast quantities of rice. The river is the chief artery of the country: on its banks stand the principal towns, Bassein, Rangoon, Prome, Ava, Mandalay, Bhamo; its banks were the home of Burmese civilisation; its waters have served as the main means of communication not only to the interior of Burma, but to the south-western provinces of China and of Tibet. The river drains an area of at least 158,000 sq. m. Its largest affluent, coming from the right hand, is the Chindwin. This and the two left-hand tributaries, the Shweli and Myit-nge, are alone navigable. The plain for 150 miles from the sea, being liable to annual inundations, has been protected by embankments built along each side of the river since 1863. The carriage of goods and merchandise is shared between the steamers of the English 'Irawadi Flotilla Company' and a numerous fleet of native boats. For the question of origin, see General Walker's papers in Proc. Roy. Geog. Soc. (1887 and 1888).