Also found in: Dictionary, Thesaurus, Wikipedia.


Ayeyarwady (īˌyärwädˈē) or Irrawaddy (ĭrəwŏdˈē), chief river of Myanmar, c.1,000 mi (1,600 km) long, formed by the confluence of the Mali and Nmai rivers in N Myanmar. The combined stream flows south through gorges strewn with rapids past Myitkyina, Bhamo, Mandalay, Pakokku, and Pyay; it receives the Chindwinn River, its principal tributary, just above Pakokku. The vast Ayeyarwady delta (c.200 mi/320 km wide), one of the world's great rice-producing regions, begins at Hintada, c.180 mi (290 km) from the Andaman Sea. On a mouth of the Ayeyarwady is the capital and port of Yangon. The Ayeyarwady is one of the great rivers of Asia and serves as the economic lifeline of Myanmar. It is navigable by steamers to Bhamo (c.650 mi/1,050 km upstream) and by launches up to Myitkyina. For many centuries it was Myanmar's principal communication route.
The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



the largest river in Burma. (Its headwaters are in China.) Length, 2,150 km. Basin area, 430,000 sq km (according to other data, 415,000 sq km).

The Irrawaddy rises in the eastern spurs of the Himalayas and flows mainly from north to south. In its upper course the Irrawaddy and its tributaries flow in deep gorges through jungles and have channels full of rapids. Below the city of Myitkyina the Irrawaddy valley broadens, and the channel becomes 800 m wide. The river then cuts across the western part of the Shan Upland, forming three gorges where the channel is 50–100 m wide and where in places there are whirlpools that constitute a danger to navigation. In its middle and lower course the Irrawaddy crosses the extensive Irrawaddy Plain, where the river forms a broad, terraced valley. A flat, very swampy delta covered with jungles begins 300 km from the mouth of the river. The delta has an area of up to 30,000 sq km (according to other sources, 48,000 sq km); along the coast of the Andaman Sea the delta extends for 240 km and is separated from the sea by a belt of sand dunes. The delta is formed by numerous channels and arms; Rangoon and Bassein are the largest ones and are navigable. The water is muddy, and the river carries about 250 million tons of sediments annually, owing to which the delta is advancing out into the sea at an average rate of 40–50 m a year.

The Irrawaddy has a monsoon regimen. Because of the monsoon rains, the river begins to rise in April and continues to rise until August or September, after which the water begins to drop. The amplitude of fluctuations in water level is 8–11 m, and during high water the width of the river increases in places by four to five times; thus, in the middle course at the city of Mandalay the width of the river changes from 2 km to 10 km. In its lower course the Irrawaddy experiences high tides which reach a height of 4—4.5 m at the city of Rangoon. The average water discharge in the river’s lower course is 13,000–14,000 cu m per sec, but during particularly heavy rains it can reach 40,000 cu m per sec, and sometimes even more. Catastrophic floods are frequent. The river is navigable for a distance of 1,100 km upstream, and for a distance of 1,440 km in the summer (to the city of Bhamo); small boats can ascend to the city of Myitkyina (1,600 km from the mouth). In the middle and lower course the waters of the Irrawaddy and its tributaries are used for irrigation. In its upper course timber is rafted. The river’s tremendous power resources are hardly used at all. The cities of Mandalay, Prome, and Henzada are on the Irrawaddy; Rangoon—Burma’s capital—is in the delta on an arm of the Irrawaddy.

A. P. Muranov

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


the main river in Myanmar, rising in the north in two headstreams and flowing south through the whole length of Myanmar, to enter the Andaman Sea by nine main mouths. Length: 2100 km (1300 miles)
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
Sources contacted by The Irrawaddy said the 60 mm mortar shell came from a Tatmadaw artillery base.
The Irrawaddy dolphin nearly became extinct and is currently classified as endangered.
(17) For example, "Bertil Lintner: 'They Don't Just Want a Ceasefire, They Want to Talk About the Future of the Country'", The Irrawaddy, 3 September 2015, available at <>.
I wish I could help all the kind people of this amazing country, all the lonely street dogs, and all the Irrawaddy river dolphins.
China needs to consider that the project might provoke more conflict in the ethnic areas," The Irrawaddy quoted Khin Khin Kyaw Kyee, a lead researcher at the Institute for Strategy and Policy-Myanmar, as saying.
Irrawaddy dolphins have been declared endangered by the International Union for Conservation of Nature, he added.
the third river is the Pumfleu, emptying into the sea at Cosmin near Arakan [on the western channel of the Irrawaddy delta], the fourth river is presumed to be the Ganges of Chittagong.
Right side dorsal fin photographs of adult Irrawaddy dolphins were imported in Photos 1.5 for iOS 2015, a photograph-editing program.
- VAR of flood-affected residents waiting for supplies in Kyouk Taing village near Nyaung Don township in Myanmar's Irrawaddy region.
"If the Don Sahong dam is built, it will lead to the extinction of Mekong (Irrawaddy) dolphins," Chhith Sam Ath, WWF-Cambodia's country director, told reporters.
As part of her trip, Collins was able to meet some of the children at the Pauk Taw Pauk Myaing Village school, which is a few miles downstream from Mandalay on the banks of the Irrawaddy River.
"Burma and China don't have bilateral trade agreement yet [for rice], even though the Burmese government asks for it every time they meet with China," Aung said, according to the ( Irrawaddy .