Mekong

Mekong (Mae Nam Khong)
Láncāng Jiāng, Mae Khaung, แม่น้ำโขง (Maenam Khong), Mékôngk, Tonle Thom, Sông Cửu Long, Megaung Myit
River
View of the Mekong before sunset.
Countries  China,  Burma,  Laos,  Thailand,  Cambodia,  Vietnam
Source Lasagongma Spring
 - location Mt. Guozongmucha, Qinghai, China
 - elevation 5,224 m (17,139 ft)
 - coordinates
Mouth Mekong Delta
 - elevation 0 m (0 ft)
Length 4,909 km (3,050 mi)
Basin 795,000 km² (307,000 sq mi)
Discharge for South China Sea
 - average 16,000 m3/s (570,000 cu ft/s)
 - max 39,000 m3/s (1,400,000 cu ft/s)

The Mekong is one of the world’s major rivers. It is the world's 12th-longest river[1] and the 7th-longest in Asia. Its estimated length is 4,350 km (2,703 mi), and it drains an area of 795,000 km2 (307,000 sq mi)[2], discharging 475 km3 (114 cu mi) of water annually.

From the Tibetan Plateau this river runs through China's Yunnan province, Burma, Laos, Thailand, Cambodia and Vietnam. Laos, Thailand, Cambodia and Vietnam established the Mekong River Commission in 1995 to assist in the management and coordinated use of the Mekong's resources. In 1996 China and Burma became "dialogue partners" of the MRC and the six countries now work together within a cooperation framework.

The extreme seasonal variations in flow and the presence of rapids and waterfalls in this river have made navigation extremely difficult.

Contents

Names

In English the river is called "the Mekong River", but in the Thai languages it is essentially the "Mae Nam Khong", where "Maenam" translates as "River". "Khong" is derived from the Sanskrit "ganga", meaning the Ganges. Many Northern Thai and Laos locals refer to it as the "River Khong", suggesting its origins and the subsequent formulation of "Mekong" literally meaning "Mother Khong". Such is the case with the Mae Nam Ping in Chiang Mai which is known as the "Ping River". The Tonle Sap in Cambodia is a similar example – where Tonle translates as "Great lake or river", making the Tonle Sap River an unnecessary repetition of what is in fact the "Sap River".

In Thai, โขง (pronounced [kʰǒːŋ]) is a species of crocodile; some believe this is tone-shifted from คด [kʰót] or โค้ง [kʰóːŋ], both adjectives to describe curves or meanders of a river or road[3].

Since the river flows through a number of countries, it has many different names in local languages:

Course

It rises on the Tibetan Plateau in the Sanjiangyuan National Nature Reserve as the Lancang and flows southwest through Yunnan Province through the Three Parallel Rivers of Yunnan Protected Areas in the Hengduan Mountains. For this first part of its course it is nearly parallel to the Salween River on the west and the Yangtze River in the east. After leaving China, it flows southeast and forms the border of Burma and Laos for about 100 kilometres (62 mi) then turns southwest to form briefly the border of Laos with Thailand. The Mekong then flows east and south into Laos for some 400 kilometres (250 mi) and defines the Laos-Thailand border again for some 850 kilometres (530 mi) as it flows east, turning south through central Southeast Asia, passing through the capital of Laos, Vientiane. The Mun River’s confluence with the Mekong occurs right before it crosses into Cambodia, where it receives the Tonle Sap River, flowing by Phnom Penh, the capital of Cambodia. The Mekong slows as it enters Vietnam, where it divides into nine channels of the Mekong Delta, where Ho Chi Minh City lies. The water from the Mekong Delta flows southeast into the South China Sea.

Fauna

The Mekong basin is one of the richest areas of biodiversity in the world. Only the Amazon boasts a higher level of biodiversity.[5] Although the Amazon has higher biodiversity, the Mekong river has more biodiversity per unit area.[6] More than 1200 species of fish have been identified and there could be possibly as many as 1700. Fishing is a very important part of the economic activities in the area and a vital source of protein in the local diet. Estimates indicate that some 120 fish species are commercially traded but most of the fishery is based on 10–20 species.[7]

In the Upper Mekong, the northern part of the river down to the Burma–Thai–Laos border, the river is relatively clear and fast flowing with the influx snowmelt guaranteeing a relatively uniform circumannual flow in the river. The water tends to be neutral, with a pH of 6.9 ranging to 8.2 and the nutrient level is low. In the Lower Mekong area the river is turbid, especially during the rainy season. Due to bank erosion the water gets a rusty-tan colour from the soil. The river temperature in the Lower Mekong varies between 21.1 to 27.8 °C (70 to 82 °F) and the pH fluctuates between 6.2 to 6.5. The two main biotopic areas in the river follow the division between the Upper and Lower Mekong. The fish in the fast-flowing upper reaches are dominated by different loaches (Cobitidae), sucker catfish (Sisoridae), hillstream loach (Homalopteridae) and carp (Garrinae). The slower middle and lower parts of the river are dominated by species of carp (Cyprinidae), catfish (Siluridae, Clariidae, Schilbeidae, Bagridae, Sisoridae and Akysidae) and murrels (Chanidae and Ophicephalidae).

No other river is home to so many species of very large fish. The biggest include the giant river carp (Probarbus jullieni), which can grow up to 1.5 metres (4 ft 11 in) and weigh 70 kilograms (150 lb), the Mekong Freshwater Stingray (Himantura chaophraya), which can have a wingspan of up to 4.3 metres (14 ft), the giant pangasius (Pangasius sanitwongsei), Siamese giant carp (Catlocarpio siamensis) and the endemic Mekong giant catfish (Pangasianodon gigas), all three of which can grow up to about 3 metres (9 ft 10 in) in length and weigh 300 kilograms (660 lb). All of these are in serious decline, both because of dams and flood control and overfishing.[8]

One species of freshwater dolphin, the Irrawaddy Dolphin (Orcaella brevirostris), was once common in the whole of the Lower Mekong but is now very rare.[9]

Among other wetland mammals that have been living in and around the river are the smooth-coated otter (Lutra perspicillata) and fishing cat (Felis viverrina).

The endangered Siamese Crocodile (Crocodylus siamensis) is reported to occur along or near the Mekong but is extremely rare. The Saltwater Crocodile (Crocodylus porosus) is considered extinct within the Mekong River (where wild populations have not been seen for at least 25 years, but were once common.)

History

A map of 1715, incorrectly showing the Chao Praya river as a branch of the Mekong
The members of the French Mekong Expedition of 1866

The difficulty of navigating the river has meant that it has divided, rather than united, the people who live near it. The earliest known settlements date to 2100 BCE, with Ban Chiang being an excellent example of that early Iron Age culture. The earliest recorded civilization was the 1st century Indianised-Khmer culture of Funan, in the Mekong Delta. Excavations at Oc Eo, near modern An Giang, have found coins from as far away as the Roman Empire. This was succeeded by the Khmer culture Chenla state by around the 5th century. The Khmer empire of Angkor was the last great Indianized state in the region. From around the time of the fall of the Khmer empire, the Mekong was the frontline between the emergent states of Siam and Tonkin (North Vietnam), with Laos and Cambodia, then situated on the coast, torn between their influence.

The first European to encounter the Mekong was the Portuguese Antonio de Faria in 1540; a European map of 1563 depicts the river, although even by then little was known of the river upstream of the delta. European interest was sporadic: the Spaniards and Portuguese mounted some missionary and trade expeditions, while the Dutch Gerrit van Wuysthoff led an expedition up the river as far as Vientiane in 1641–42.

The French took a serious interest in the region in the mid-19th century, capturing Saigon in 1861, and establishing a protectorate over Cambodia in 1863.

The first systematic exploration began with the French Mekong Expedition led by Ernest Doudard de Lagrée and Francis Garnier, which ascended the river from its mouth to Yunnan between 1866 to 1868. Their chief finding was that the Mekong had too many falls and rapids to ever be useful for navigation. The river's source was located by Pyotr Kuzmich Kozlov in 1900.

From 1893, the French extended their control of the river into Laos, establishing French Indochina by the first decade of the 20th century. This lasted until the First and Second Indochina Wars ended French and American involvement in the region began.

After the Vietnam War, the tensions between the U.S.-backed Thai government and the new Communist governments in the other countries prevented cooperation on use of the river.

Bridges

The Thai–Lao Friendship Bridge (Thai: สะพาน มิตรภาพ ไทย-ลาว Saphan Mittaphap Thai-lao) connects Nong Khai city with Vientiane in Laos. The 1,170-metre (3,840 ft)-long bridge has two 3.5-metre (11 ft)-wide lanes with an unfinished single railway line in the middle. On March 20, 2004, the Thai and Lao governments agreed to extend the railway to Tha Nalaeng in Laos.

The Second Thai–Lao Friendship Bridge connects Mukdahan to Savannakhet. The two-lane, 12-metre (39 ft)-wide, 1,600-metre (5,200 ft)-long bridge opened to the general public on January 9, 2007.

There are only three bridges, located in Champasak province, in Laos. Unlike the Friendship bridges, this bridge is not a border crossing. It is 1,380 metres (4,528 ft) long, and was completed in 2000 (Pakxe bridge ).

A new bridge over the Mekong is to be completed by 2011, connecting the border towns of Chiang Khong (Thailand) and Ban Houayxay (Laos), as part of Asian Highway 3. The Chinese and Thai governments agreed to build the bridge and share the estimated $33USD million dollar cost of the project.

Cambodia has one two-lane bridge, the Kizuna bridge in the city of Kompong Cham, on the road linking Phnom Penh with the remote provinces of Ratanakiri and Mondolkiri, and further away Laos.

The Prek Tamak Bridge, 40 km north of Phnom Penh will provide another link in 2011.

Phnom Penh itself has no bridge under construction yet.

In Vietnam, since the year 2000 My Thuan Bridge (Mỹ Thuận), crosses the first channel a dozen km ahead of Vinh Long (Vĩnh Long) and since 2008 Rach Mieu Bridge (Rạch Miễu) crosses it a dozen km ahead of de My Tho (Mỹ Tho), between the provinces de Tien Giang (Tiền Giang) and Ben Tre (Bến Tre).

Can Tho Bridge (Cần Thơ), should cross the second channel in 2010; this was a delayed because of a heavy accident in 2007.

Dams

China Western Development[10]

Mekong Dams compl. MW Geo coordinate
Gongguoqiao Dam 2008 750
Xiaowan Dam 2013 4200
Manwan Dam 1996 1500
Dachaoshan Dam 2003 1350
Nuozhadu Dam 2017 5850
Jinghong Dam 2010 1750
Ganlanba Dam n/a 150
Mengsong Dam n/a 600

Environmental concerns

Crossing the Mekong by ferry, near Champasak, Laos

The two most current issues facing the river are the building of dams and blasting of rapids.

A number of dams have already been built on the river's tributaries, notably the Pak Mun dam in Thailand. This has been criticised on grounds of cost as well as damage to the environment and to the livelihoods of affected villagers, though none have been built on the main part itself.

China is engaged in an extensive program of dam-building on the river itself: it has already completed three, the first called the Manwan dam, another twelve are under consideration.

Poverty stricken Cambodia is one nation that is completely dependent on the river for food and the vast majority of its fledgling economy. The annual floods provide much needed water for crops of the otherwise dry dusty land, and to refresh Tonle Sap, yet its major cities are all vulnerable to flooding. The Tonle Sap Biosphere Reserve has been created to try to protect areas around the Tonle Sap Lake and river, which is connected to the Mekong.[11]

The Mekong River Commission, a panel of the region's nations, has accused China of blatantly disregarding the nations downstream in its plans to dam the river in an effort to stop the dams, but to no avail. Since the building of the first Chinese dam, many species have become endangered, including the Mekong Dolphin and dugong, water levels have dropped as ferries get stuck, fish caught are small and the catch is less than half of before the dam, the turnover at Chiang Rai port is less than one fourth of previous years, and crossings from Chiang Rai to isolated Luang Prabang have lengthened from 8 hours to 2 days due to inadequate water levels.

Despite all these problems, new dams planned will have significantly worse impact if carried out as planned. All nations downstream and the environment will suffer from added pollution (due to development and relatively lax regulation and enforcement in China compared to Thailand, poisoning the food supply from pesticide runoff and heavy industry, as well as promoting algal blooms from organophosphates from agriculture, as well as water hyacinth infestation), river blockage problems as fish cannot swim upstream to spawn, and potentially devastating very low water flow.

Other environmental concerns arise from increased water flow in some parts as China clears rocks and sandbars, blasts gorges, and slows water as it dams and floods other sections, and relocates indigenous peoples. Cambodia is by far the most exposed, depending on a fine balance of water flow, fearing scenarios of mass famine and devastating floods, the likes of which destroyed the Angkor kingdom 700 years ago. Laos' biggest cities all hug the Mekong as does Vietnam's largest city and financial hub, Ho Chi Minh City, which would be vulnerable mostly to low flow and pollution.

Protected areas

Miscellany

See also

References

Notes

  1. ↑ http://www.rrcap.unep.org/pub/GMEO/GMEO_2007_01overview.pdf
  2. ↑ Source of the Mekong River (Langcang Jiang)
  3. ↑ Thai folk: The knowledge of Thai life-style
  4. ↑ The Chinese name of Lan Xang is both Nanzhang and Láncāng
  5. ↑ www.mrcmekong.org/download/.../Mekong_Development_No2.pdf
  6. ↑ www.mrcmekong.org/download/.../Mekong_Development_No2.pdf
  7. ↑ Mekong Development
  8. ↑ ASEAN Regional Centre for Biodiversity Conservation
  9. ↑ IUCN Red list
  10. ↑ Probe International 30.06.2006 The Hydrolancang cascade
  11. ↑ http://www.tsbr-ed.org

Bibliography

External links

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