Ayeyarwaddy edit
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Irrawaddy (ဧရာဝတီမြစ်)
Ayeyarwady
none Course of the Irrawaddy River
Course of the Irrawaddy River
Country Myanmar
Major cities Myitkyina, Mandalay, Bhamo
Length 2,170 km (1,348 mi)
Watershed 411,000 km² (158,688 sq mi)
Primary source Mali River
 - coordinates 28°N 22°E / 28, 22
Other source N'Mai River
 - coordinates 28°N 4°E / 28, 4
Source confluence
 - location Damphet, Kachin State
 - coordinates 25°N 42°E / 25, 42
 - elevation 147 m (482 ft)
Mouth Andaman Sea
 - location Ale-ywa, Ayeyarwady Division, Myanmar
 - coordinates 15°N 51°E / 15, 51
 - elevation m (10 ft)
Major tributaries
 - left Chindwin, Mu
 - right Myitnge
Irrawaddy watershed
Irrawaddy watershed

The Ayeyarwady River or Irrawaddy River (Burmese: ဧရာဝတီမြစ်; MLCTS: erawa.ti mrac, pronounced [ʔèjàwədì mjiʔ]) is a river that flows from north to south of Burma (Myanmar). It is the country's largest river (about 1350 miles or 2170 km long) and its most important commercial waterway, with a drainage area of about 158,700 square miles (411,000 km²).

Contents

Etymology

The names Irrawaddy and Ayeyarwady are believed to have derived either from the Sanskrit name Iravati, a sacred river and minor goddess in Indian mythology, or from her son Airavata, the elephant mount of Indra.

The Irrawaddy gives its name to a dolphin, the Irrawaddy dolphin (Orcaella brevirostris), which is found in the upper reaches of the river and known to help fishermen who practise cast-net fishing. Though sometimes called the Irrawaddy River Dolphin, it is not a true river dolphin, since it is also found at sea.12

Physiography

The Ayeyarwaddy River bisects the country from north to south and empties through a nine-armed Irrawaddy Delta into the Indian Ocean: it arises by the confluence of the N'mai and Mali Rivers in Kachin State Kachin. Both the N'mai and Mali Rivers find their sources in the Himalaya glaciers of Northern Myanmar, in the vicinity of 28° N . The eastern branch of the two, N'mai river3 , is the larger stream, but it is unnavigable because of the strong current whereas the smaller western branch, the Mali river, is navigable, despite a few rapids.

The town of Bhamo, about 150 miles (240km) south of the Mali and N'mai river confluence, is the northernmost city reachable by boat all the year round although during the monsoons most of the river cannot be used by boats. The city of Myitkyina however lies 30 miles south of the confluence and can be reached during the dry season.

Defiles

Between Myitkyina and Mandalay, the Irrawaddy flows through three well-marked defiles4 :

This sheet of lava is the Singu Plateau, a volcanic field from the Holocene. This field exists of magma from the fissure vents and cover an area of about 62 sq km. The plateau is also known as Letha Taung.6

Leaving this plateau at Kyaukmyaung 7, the river follows a broad, open course through the central dry zone8 - the ancient cultural heartland9 — where large areas consist of alluvium flats. From Mandalay (the former capital of the kingdom of Myanmar), the river makes an abrupt westward turn before curving southwest to unite with the Chindwin River, after which it continues in a southwestern direction. It is probable that the upper Irrawaddy originally flowed south from Mandalay, discharging its water through the present Sittoung River 10 to the Gulf of Martaban, and that its present westward course is geologically recent. Below its confluence with the Chindwin, the Irrawaddy continues to meander through the petroleum producing city of Yenangyaung, below which it flows generally southward. In its lower course, between Minbu and Prome, it flows through a narrow valley between forest-covered mountain ranges—the ridge of the Rakhine Yoma Mountains1112 to the west and that of the Pegu Yoma Mountains to the east.1314

The Irrawaddy Delta

Main article: Irrawaddy Delta

The delta of the Irrawaddy begins about 58 miles (93 km) above Hinthada (Henzada) and about 180 miles (290 km) from its curved base, which faces the Andaman Sea. The westernmost distributary of the delta is the Pathein (Bassein) River, while the easternmost stream is the Yangon River, on the left bank of which stands Myanmar’s capital city, Yangon (Rangoon). Because the Yangon River15 is only a minor channel, the flow of water is insufficient to prevent Yangon Harbour from silting up, and dredging is necessary. The relief of the delta’s landscape is low but not flat.16The soils consist of fine silt, which is replenished continuously by fertile alluvium carried downstream by the river. As a result of heavy rainfall varying from 80 to 120 inches a year in the delta,17 and the motion and sediment load of the river,18 the delta surface extends into the Andaman Sea at a rate of about 165 feet (50 metres) per year.19

Tributaries

  1. Taping River
  2. Shweli River
  3. Myitnge River
  4. Mu River
  5. Chindwin River

Economy and Politics

Major cities and towns

Ayeyarwady River from Sagaing Hill, Sagaing

The river flows through the following cities:

Bridges

The Ava Bridge near Sagaing, rebulit in 1954 after the wartime destruction of the original bridge built in 1934, was the only bridge over the Ayeyarwady until 1998.

Until the construction of the Ava (Innwa) Bridge, a 16 span rail and road cantilever bridge built by the British colonial government in 1934, the only way across the Irrawaddy was by ferry. The bridge was destroyed by the retreating British Army during the World War II and was rebuilt in 1954 after Burmese independence and was the only bridge to span the Ayeyarwady until recent times when a spate of bridge construction has been carried out by the government.2021

  1. Ayeyarwady Bridge (Yadanabon) just upstream from the old Ava Bridge at Sagaing
  2. Bala Min Htin Bridge over the N'Mai Hka at Myitkyina, November 1998
  3. Anawrahta Bridge at Chauk, April 2001 22
  4. Ayeyarwady-Magway Bridge at Magway
  5. Bo Myat Tun Bridge at Nyaungdon, November 1999
  6. Nawaday Bridge at Pyay, September 1997
  7. Maubin Bridge at Maubin, February 1998
  8. Ayeyarwady-Dedaye Bridge at Dedaye23

Gallery

Notes

  1. ^ Brian D Smith et al. Asian Marine Biology 1997:Investigation of Cetaceans in the Ayeyarwady River and Northern Coastal Waters of Myanmar. Hong Kong University Press. p. 173. http://books.google.co.uk/books?id=7UEJcYiT5eoC&pg=PA173&lpg=PA173&dq=ayeyarwady+river+bridges&source=web&ots=f3lrzEzgC1&sig=I8YRQYYfXoHCsdldo5GZb9zMcCU&hl=en&sa=X&oi=book_result&resnum=1&ct=result#PPA173,M1. Retrieved on 2008-10-06. 
  2. ^ Tint Tun. "Irrawaddy Dolphin". Retrieved on 2008-10-06.
  3. ^ Document about the floradiversity in Northern Kachin, in the N'mai watershed. Studies on Floradiversity of North-eastern Kachin Myanmar Section of Sino-himalaya (N'mai Hka-Than Lwin Water Division) - Ma Kalayar Lu, Myitkyina University, faculty of Botanics, 28-8-06. retrieved d.d. 6-12-2008.
  4. ^ Encyclopedia Britannica Online topic: Physical features » Physiography, paragraph 3. Retrieved d.d. 5-12-2008
  5. ^ Kabwet, Myanmar: topografische & klimatografische informatie over Kabwet
  6. ^ Global Volcanism Program - vulkanologic ranking.
  7. ^ Location of Kyaukmyaung in Google Maps geocode
  8. ^ "All areas with P/PET ratio less than 0.65" according to the definition of the Convention on Biological Diversity, retrieved d.d. 16-12
  9. ^ Thomas Streissguth, Myanmar in pictures, Twenty-First Century Books, 2007. ISBN: 0822571463. Retrieved d.d. 16-12.
  10. ^ Gewijzigde riviernamen in Myanmar
  11. ^ Rakhine State op Travel Myanmar
  12. ^ Rakhine Mountain Range on The Free Dictionary Encyclopedia
  13. ^ Article about the Bago Mountains on Encyclopedia Britannica Online.
  14. ^ Basic information about the Bago Division on the site of the Myanmar Government
  15. ^ Information about sediment dynamics in the Yangon River at the site of National Center for Biotechnology Information. Retrieved d.d. 17/12/2008
  16. ^ Profile of the Irrawaddy Delta from Henzhada to the river mouth, in feet
  17. ^ Map on the rainfall in Myanmar retrieved d.d. 17-12-2008.
  18. ^ A detailed documentation of sediment dynamics can be found in The Journal of Geology
  19. ^ Encyclopedia Britannica Online Physiography, alinea 4. Retrieved d.d. 17-12-2008.
  20. ^ ""Big Push" for Sustained Development". Perspective, August 2000. Retrieved on 2008-10-06.
  21. ^ "Roads and Bridges". Union Solidarity and Development Association April 7, 2006. Retrieved on 2008-10-06.
  22. ^ "Sr General Than Shwe attends opening of Anawrahta Bridge linking Chauk and Seikphyu on Ayeyawady River", The New Light of Myanmar, April 5, 2001, http://www.myanmargeneva.org/01nlm/n010405.htm#(1), retrieved on 6 October 2008 
  23. ^ "The Nation's Longest Bridge Inaugurated". Perspective, November 1999. Retrieved on 2008-10-06.

External links

Coordinates: 15°50′N 95°06′E / 15.833, 95.1