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Mekong

The Mekong or Mekong River is a trans-boundary river in East Asia and Southeast Asia. It is the world's twelfth longest river and the third longest in Asia.[1] Its estimated length is 4,909 km (3,050 mi),[1] and it drains an area of 795,000 km2 (307,000 sq mi), discharging 475 km3 (114 cu mi) of water annually.[2] From the Tibetan Plateau the river runs through China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. The extreme seasonal variations in flow and the presence of rapids and waterfalls in the Mekong make navigation difficult. Even so, the river is a major trade route between western China and Southeast Asia. The construction of hydroelectric dams along the Mekong in recent decades causes serious problems for the river's ecosystem, including the exacerbation of drought.[3][4][5]

Mekong River
湄公河 (Méigōng Hé) / 澜沧江 (Láncāng Jiāng)
မဲခေါင်မြစ် (Megaung Myit)
ແມ່ນ້ຳຂອງ (Maenam Khong)
แม่น้ำโขง (Maenam Khong)
ទន្លេមេគង្គ (Tônlé Mékôngk)
Sông Mê Kông / Sông Cửu Long (九龍)
Mekong River, Luang Prabang, Laos
Mekong River watershed
Location
CountryChina, Myanmar, Laos, Thailand, Cambodia, Vietnam
Physical characteristics
SourceLasaigongma (拉赛贡玛) Spring
 • locationMt. Guozongmucha (果宗木查), Zadoi, Yushu Tibetan Autonomous Prefecture, Qinghai, China
 • coordinates33°42.5′N 94°41.7′E / 33.7083°N 94.6950°E / 33.7083; 94.6950
 • elevation5,224 m (17,139 ft)
MouthMekong Delta
 • location
Vietnam
 • coordinates
10°11′N 106°45′E / 10.19°N 106.75°E / 10.19; 106.75Coordinates: 10°11′N 106°45′E / 10.19°N 106.75°E / 10.19; 106.75
 • elevation
0 m (0 ft)
Length4,350 km (2,700 mi)
Basin size795,000 km2 (307,000 sq mi)
Discharge 
 • locationMekong Delta, South China Sea
 • average16,000 m3/s (570,000 cu ft/s)
 • minimum1,400 m3/s (49,000 cu ft/s)
 • maximum39,000 m3/s (1,400,000 cu ft/s)
Basin features
Tributaries 
 • leftSrepok, Nam Khan, Tha, Nam Ou
 • rightMun, Tonlé Sap, Kok, Ruak

Names

The Mekong was originally called Mae Nam Khong from a contracted form of Tai shortened to Mae Khong.[6] In Thai and Lao, Mae Nam ("Mother of Water[s]") is used for large rivers and Khong is the proper name referred to as "River Khong". However, Khong is an archaic word meaning "river", loaned from Austroasiatic languages, such as Vietnamese sông (from *krong) and Mon kruŋ "river", which led to Chinese whose Old Chinese pronunciation has been reconstructed as /*kˤroŋ/[7] and which long served as the proper name of the Yangtze before becoming a generic word for major rivers. To the early European traders, the Mekong River was also known as Mekon River, May-Kiang River and Cambodia River.[8][9][10][11][12]

The local names for the river include:

  1. From Tai:
  2. Other:
    • Vietnamese: Sông Cửu Long, (九龍 Nine Dragons River [ʂə̄wŋm kɨ̂w lāwŋm]).
    • Khmer: ទន្លេធំ Tônlé Thum [tɔnlei tʰum] (lit. "Big River" or "Great River").
    • Khmuic: [ŏ̞m̥ kʰrɔːŋ̊], 'ŏ̞m̥' means 'river' or 'water', here it means 'river', 'kʰrɔːŋ̊' means 'canal'. So 'ŏ̞m̥ kʰrɔːŋ̊' means 'canal river'. In the ancient time Khmuic people called it '[ŏ̞m̥ kʰrɔːŋ̊ ɲă̞k̥]' or '[ŏ̞m̥ kʰrɔːŋ̊ ɟru̞ːʔ]' which means 'giant canal river' or 'deep canal river' respectively.

Course

The Mekong rises as the Za Qu (Tibetan: རྫ་ཆུ་, Wylie: rDza chu, ZYPY: Za qu; Chinese: 扎曲; pinyin: Zā Qū) and soon becomes known as the Lancang (simplified Chinese: 澜沧江; traditional Chinese: 瀾滄江; pinyin: Láncāng Jiāng, from the old name of Lao kingdom Lan Xang; the characters may also be literally understood as "turbulent green river"). It originates in the "three rivers source area" on the Tibetan Plateau in the Sanjiangyuan National Nature Reserve. The reserve protects the headwaters of, from north to south, the Yellow (Huang He), the Yangtze, and the Mekong Rivers.[2] It flows through the Tibetan Autonomous Region and then southeast into Yunnan Province, and then the Three Parallel Rivers Area in the Hengduan Mountains, along with the Yangtze to its east and the Salween River (Nu Jiang in Chinese) to its west.

Then the Mekong meets the China–Myanmar border and flows about 10 km (6.2 mi) along that border until it reaches the tripoint of China, Myanmar and Laos. From there it flows southwest and forms the border of Myanmar and Laos for about 100 km (62 mi) until it arrives at the tripoint of Myanmar, Laos, and Thailand. This is also the point of confluence between the Ruak River (which follows the Thai–Myanmar border) and the Mekong. The area of this tripoint is sometimes termed the Golden Triangle, although the term also refers to the much larger area of those three countries that was notorious as a drug producing region.

From the Golden Triangle tripoint, the Mekong turns southeast to briefly form the border of Laos with Thailand.

Khon Pi Long is a series of rapids along a 1.6-kilometre section of the Mekong River dividing Chiang Rai and Bokeo Province in Laos. The name of the rapids means 'where the ghost lost its way'.[13] It then turns east into the interior of Laos, flowing first east and then south for some 400 km (250 mi) before meeting the border with Thailand again. Once more, it defines the Laos-Thailand border for some 850 km (530 mi) as it flows first east, passing the capital of Laos, Vientiane, then turns south. A second time, the river leaves the border and flows east into Laos soon passing the city of Pakse. Thereafter, it turns and runs more or less directly south, crossing into Cambodia.

At Phnom Penh the river is joined on the right bank by the river and lake system the Tonlé Sap. When the Mekong is low, the Tonle Sap is a tributary: water flows from the lake and river into the Mekong. When the Mekong floods, the flow reverses: the floodwaters of the Mekong flow up the Tonle Sap.

Immediately after the Sap River joins the Mekong by Phnom Penh, the Bassac River branches off the right (west) bank. The Bassac River is the first and main distributary of the Mekong. This is the beginning of the Mekong Delta. The two rivers, the Bassac to the west and the Mekong to the east, enter Vietnam shortly after this. In Vietnam, the Bassac is called the Hậu River (Sông Hậu or Hậu Giang); the main, eastern, branch of the Mekong is called the Tiền River or Tiền Giang. In Vietnam, distributaries of the eastern (main, Mekong) branch include the Mỹ Tho River, the Ba Lai River, the Hàm Luông River, and the Cổ Chiên River.

Drainage basin

 
Mekong River south of Chamdo.
 
The Mekong from Phou si
 
The confluence of the Mekong and the Nam Ou Rivers, Laos

The Mekong Basin can be divided into two parts: the "upper Mekong basin" in Tibet, and the "lower Mekong basin" from Yunnan downstream from China to the South China Sea.[14] From the point where it rises to its mouth, the most precipitous drop in the Mekong occurs in the upper Mekong basin, a stretch of some 2,200 km (1,400 mi). Here, it drops 4,500 m (14,800 ft) before it enters the lower basin where the borders of Thailand, Laos, China, and Myanmar come together in the Golden Triangle. Downstream from the Golden Triangle, the river flows for a further 2,600 km (1,600 mi) through Laos, Thailand, and Cambodia before entering the South China Sea via a complex delta system in Vietnam.[14]

Upper basin

The upper basin makes up 24% of the total area and contributes 15–20% of the water that flows into the Mekong River. The catchment here is steep and narrow. Soil erosion has been a major problem and approximately 50% of the sediment in the river comes from the upper basin.

In Yunnan Province in China, the river and its tributaries are confined by narrow, deep gorges. The tributary river systems in this part of the basin are small. Only 14 have catchment areas that exceed 1,000 km2 (390 sq mi), yet the greatest amount of loss of forest cover in the entire river system per square kilometer has occurred in this region due to heavy unchecked demand for natural resources. In the south of Yunnan, in Simao and Xishuangbanna Prefectures, the river changes as the valley opens out, the floodplain becomes wider, and the river becomes wider and slower.

Lower basin

Major tributary systems develop in the lower basin. These systems can be separated into two groups: tributaries that contribute to the major wet season flows, and tributaries that drain low relief regions of lower rainfall. The first group are left bank tributaries that drain the high rainfall areas of Laos. The second group are those on the right bank, mainly the Mun and Chi Rivers, that drain a large part of northeast Thailand.

Laos lies almost entirely within the lower Mekong basin. Its climate, landscape and land use are the major factors shaping the hydrology of the river. The mountainous landscape means that only 16% of the country is farmed under lowland terrace or upland shifting cultivation.[14] With upland shifting agriculture (slash and burn), soils recover within 10 to 20 years but the vegetation does not. Shifting cultivation is common in the uplands of northern Laos and is reported to account for as much as 27% of the total land under rice cultivation.[14] As elsewhere in the basin, forest cover has been steadily reduced during the last three decades by shifting agriculture and permanent agriculture. The cumulative impacts of these activities on the river regime have not been measured. However, the hydrological impacts of land cover changes induced by the Vietnam War were quantified in two sub-catchments of the lower Mekong River basin.[15]

Loss of forest cover in the Thai areas of the lower basin has been the highest of all the lower Mekong countries over the past 60 years. On the Khorat Plateau, which includes the Mun and Chi tributary systems, forest cover was reduced from 42% in 1961 to 13% in 1993.[14] Although this part of northeast Thailand has an annual rainfall of more than 1,000 mm, a high evaporation rate means it is classified as a semi-arid region. Consequently, although the Mun and Chi basins drain 15% of the entire Mekong basin, they only contribute 6% of the average annual flow.[14] Sandy and saline soils are the most common soil types, which makes much of the land unsuitable for wet rice cultivation. In spite of poor fertility, however, agriculture is intensive. Glutinous rice, maize, and cassava are the principal crops.[14] Drought is by far the major hydrological hazard in this region.[14]

 
Floating homes on the Mekong, Cambodia

As the Mekong enters Cambodia, over 95% of its flows have already joined the river.[14] From here on downstream the terrain is flat and water levels rather than flow volumes determine the movement of water across the landscape. The seasonal cycle of changing water levels at Phnom Penh results in the unique "flow reversal" of water into and out of the Great Lake via the Tonle Sap River. Phnom Penh also marks the beginning of the delta system of the Mekong River. Here the mainstream begins to break up into an increasing number of branches.[14]

In Cambodia, wet rice is the main crop and is grown on the flood plains of the Tonle Sap, Mekong, and Bassac (the Mekong delta distributary known as the Hậu in Vietnam) Rivers.[14] More than half of Cambodia remains covered with mixed evergreen and deciduous broadleaf forest, but forest cover has decreased from 73% in 1973 to 63% in 1993.[14] Here, the river landscape is flat. Small changes in water level determine the direction of water movement, including the large-scale reversal of flow into and out of the Tonle Sap basin from the Mekong River.[14]

 
Mekong Delta, Vietnam

The Mekong delta in Vietnam is farmed intensively and has little natural vegetation left. Forest cover is less than 10%. In the Central Highlands of Vietnam, forest cover was reduced from over 95% in the 1950s to around 50% in the mid-1990s.[14] Agricultural expansion and population pressure are the major reasons for land use and landscape change. Both drought and flood are common hazards in the Delta, which many people believe is the most sensitive to upstream hydrological change.[14]

Water flow along its course

Table 1: Country share of Mekong River Basin (MRB) and water flows[14]

China Myanmar Laos Thailand Cambodia Vietnam Total
Basin area (km2) 165,000 24,000 202,000 184,000 155,000 65,000 795,000
Catchment as % of MRB 21 3 25 23 20 8 100
Flow as % of MRB 16 2 35 18 18 11 100

By taking into account hydrological regimes, physiography land use, and existing, planned and potential resource developments, the Mekong is divided into six distinct reaches:[14]

 
The Mekong in Laos

Reach 1: Lancang Jiang or Upper Mekong River in China. In this part of the river, the major source of water flowing into the river comes from melting snow on the Tibetan plateau. This volume of water is sometimes called the "Yunnan component" and plays an important role in the low-flow hydrology of the lower mainstream. Even as far downstream as Kratie, the Yunnan component makes up almost 30% of the average dry season flow. A major concern is that the ongoing and planned expansion of dams and reservoirs on the Mekong mainstream in Yunnan could have a significant effect on the low-flow regime of the lower Mekong basin system.[14][16][17]

Reach 2: Chiang Saen to Vientiane and Nong Khai. This reach is almost entirely mountainous and covered with natural forest although there has been widespread slash and burn agriculture. Although this reach cannot be termed "unspoiled", the hydrological response is perhaps the most natural and undisturbed of all the lower basin. Many hydrological aspects of the lower basin start to change rapidly at the downstream boundary of this reach.[14]

On 19 July 2019 this reach of the river dropped to its lowest level in a century. Officials are particularly concerned as July is in the wet season, when mainstream flows are abundant historically. Locals are blaming low water on the newly constructed Xayaburi Dam, as it enters its test phase prior to the start of commercial operation in October 2019.[18]

Reach 3: Vientiane and Nong Khai to Pakse. The boundary between Reach 2 and 3 is where the Mekong hydrology starts to change. Reach 2 is dominated in both wet and dry seasons by the Yunnan Component. Reach 3 is increasingly influenced by contributions from the large left bank tributaries in Laos, namely the Nam Ngum, Nam Theun, Nam Hinboun, Se Bang Fai, Se Bang Hieng and Se Done Rivers. The Mun-Chi river system from the right bank in Thailand enters the mainstream within this reach.[14]

Reach 4: Pakse to Kratie. The main hydrological contributions to the mainstream in this reach come from the Se Kong, Se San, and Sre Pok catchments. Together, these rivers make up the largest hydrological sub-component of the lower basin. Over 25% of the mean annual flow volume to the mainstream at Kratie comes from these three river basins. They are the key element in the hydrology of this part of the system, especially to the Tonle Sap flow reversal.[14]

Reach 5: Kratie to Phnom Penh. This reach includes the hydraulic complexities of the Cambodian floodplain, the Tonle Sap and the Great Lake. By this stage, over 95% of the total flow has entered the Mekong system. The focus turns from hydrology and water discharge to the assessment of water level, over- bank storage and flooding and the hydrodynamics that determine the timing, duration and volume of the seasonal flow reversal into and out of the Great Lake.[14]

Reach 6: Phnom Penh to the South China Sea. Here the mainstream divides into a complex and increasingly controlled and artificial system of branches and canals. Key features of flow behaviour are tidal influences and salt water intrusion. Every year, 35–50% of this reach is flooded during the rainy season. The impact of road embankments and similar infrastructure developments on the movement of this flood water is an increasingly important consequence of development.[14]

Table 2 summarises the mean annual flows along the mainstream. The mean annual flow entering the lower Mekong from China is equivalent to a relatively modest 450 mm depth of runoff. Downstream of Vientiane this increases to over 600 mm as the principal left bank tributaries enter the mainstream, mainly the Nam Ngum and Nam Theun. The flow level falls again, even with the right bank entry of the Mun-Chi system from Thailand. Although the Mun–Chi basin drains 20% of the lower system, average annual runoff is only 250 mm. Runoff in the mainstream increases again with the entry from the left bank of the Se Kong from southern Laos and Se San and Sre Pok from Vietnam and Cambodia.

 
Floating market, Cần Thơ, Mekong delta
 
Cầu khỉ (monkey bridge) and small nước mắm (fish sauce) workshop on the bank of the Tiền River (branch of Mekong), Binh Dai District, Ben Tre Province, Vietnam
 
Hamlet, Tiền River, Binh Dai District, Ben Tre Province, Vietnam

Table 2: Lower Mekong Mainstream annual flow (1960 to 2004) at selected sites.[14]

Mainstream site Catchment area (km2) Mean annual flow as % total Mekong
Discharge m3/s Volume km3 Runoff (mm)
Chiang Saen 189,000 2,700 85 450 19
Luang Prabang 268,000 3,900 123 460 27
Chiang Khan 292,000 4,200 133 460 29
Vientiane 299,000 4,400 139 460 30
Nong Khai 302,000 4,500 142 470 31
Nakhon Phanom 373,000 7,100 224 600 49
Mukdahan 391,000 7,600 240 610 52
Pakse 545,000 9,700 306 560 67
Stung Treng 635,000 13,100 413 650 90
Kratié 646,000 13,200 416 640 91
Basin Total 760,000 14,500 457 600 100

Flows at Chiang Saen entering the lower basin from Yunnan make up about 15% of the wet season flow at Kratie. This rises to 40% during the dry season, even this far downstream. During the wet season, the proportion of average flow coming from Yunnan rapidly decreases downstream of Chiang Saen, from 70% to less than 20% at Kratie. The dry season contribution from Yunnan is much more significant. The major portion of the balance comes from Laos, which points to a major distinction in the low-flow hydrology of the river. One fraction comes from melting snow in China and Tibet and the rest from over-season catchment storage in the lower basin. This has implications for the occurrence of drought conditions. For example, if runoff from melting snow in any given year is very low, then flows upstream of Vientiane-Nong Khai would be lower.[14]

In a large river system like the Mekong, seasonal flows can be quite variable from year to year. Although the pattern of the annual hydrograph is fairly predictable, its magnitude is not. The average monthly flows along the mainstream are listed in Table 3, providing an indication of their range and variability from year to year. At Pakse, for example, flood season flows during August would exceed 20,000 cubic metres per second nine years out of ten, but exceed 34,000 m3/s only one year in ten.[14]

Table 3: Mekong Mainstream monthly discharge, 1960–2004 (m3/s).[14]

Month Chiang Saen Luang Prabang Vientiane Nakhon Phanom Mukdahan Pakse Kratie
Jan 1,150 1,690 1,760 2,380 2,370 2,800 3,620
Feb 930 1,280 1,370 1,860 1,880 2,170 2,730
Mar 830 1,060 1,170 1,560 1,600 1,840 2,290
Apr 910 1,110 1,190 1,530 1,560 1,800 2,220
May 1,300 1,570 1,720 2,410 2,430 2,920 3,640
Jun 2,460 3,110 3,410 6,610 7,090 8,810 11,200
Jul 4,720 6,400 6,920 12,800 13,600 16,600 22,200
Aug 6,480 9,920 11,000 19,100 20,600 26,200 35,500
Sep 5,510 8,990 10,800 18,500 19,800 26,300 36,700
Oct 3,840 5,750 6,800 10,200 10,900 15,400 22,000
Nov 2,510 3,790 4,230 5,410 5,710 7,780 10,900
Dec 1,590 2,400 2,560 3,340 3,410 4,190 5,710

There is little evidence from the last 45 years of data of any systematic changes in the hydrological regime of the Mekong.[14]

Geology

The internal drainage patterns of the Mekong are unusual when compared to those of other large rivers.[2] Most large river systems that drain the interiors of continents, such as the Amazon, Congo, and Mississippi, have relatively simple dendritic tributary networks that resemble a branching tree.[19]

Typically, such patterns develop in basins with gentle slopes where the underlying geological structure is fairly homogeneous and stable, exerting little or no control on river morphology.[20] In marked contrast, the tributary networks of the Salween, Yangtze, and particularly the Mekong, are complex with different sub-basins often exhibiting different, and distinct, drainage patterns. These complex drainage systems have developed in a setting where the underlying geological structure is heterogeneous and active, and is the major factor controlling the course of rivers and the landscapes they carve out.[21]

The elevation of the Tibetan Plateau during the Tertiary period was an important factor in the genesis of the south-west monsoon,[22] which is the dominant climatic control influencing the hydrology of the Mekong Basin. Understanding the nature and timing of the elevation of Tibet (and the Central Highlands of Vietnam) therefore helps explain the provenance of sediment reaching the delta and the Tonle Sap Great Lake today. Studies of the provenance of sediments in the Mekong delta reveal a major switch in the source of sediments about eight million years ago (Ma).[23][24] From 36 to 8 Ma the bulk (76%) of the sediments deposited in the delta came from erosion of the bedrock in the Three Rivers Area. From 8 Ma to the present, however, the contribution from the Three Rivers Area fell to 40%, while that from the Central Highlands rose from 11 to 51%. One of the most striking conclusions of provenance studies is the small contribution of sediment from the other parts of the Mekong basin, notably the Khorat Plateau, the uplands of northern Laos and northern Thailand, and the mountain ranges south of the Three Rivers area.

The last glacial period came to an abrupt end about 19,000 years ago (19 ka) when sea levels rose rapidly, reaching a maximum of about 4.5 m above present levels in the early Holocene about 8 ka.[25] At this time the shoreline of the South China Sea almost reached Phnom Penh and cores recovered from near Angkor Borei contained sediments deposited under the influence of tides, and salt marsh and mangrove swamp deposits.[25] Sediments deposited in the Tonle Sap Great Lake about this time (7.9–7.3 ka) also show indications of marine influence, suggesting a connection to the South China Sea.[26] Although the hydraulic relationships between the Mekong and the Tonle Sap Great Lake systems during the Holocene are not well understood, it is clear that between 9,000 and 7,500 years ago the confluence of the Tonle Sap and the Mekong was in proximity to the South China Sea.

The present river morphology of the Mekong Delta developed over the last 6,000 years.[2] During this period, the delta advanced 200 km over the continental shelf of the South China Sea, covering an area of more than 62,500 km2. From 5.3 to 3.5 ka the delta advanced across a broad embayment formed between higher ground near the Cambodian border and uplands north of Ho Chi Minh City. During this phase of its development the delta was sheltered from the wave action of long-shore currents and was constructed largely through fluvial and tidal processes.[27] At this time the delta was advancing at a rate of 17–18 m per year. After 3.5 ka, however, the delta had built out beyond the embayment and became subject to wave action and marine currents. These deflected deposition south-eastwards in the direction of the Cà Mau Peninsula, which is one of the most recent features of the delta.

For much of its length the Mekong flows through bedrock channels, i.e., channels that are confined or constrained by bedrock or old alluvium in the bed and riverbanks.[2] Geomorphologic features normally associated with the alluvial stretches of mature rivers, such as meanders, oxbow lakes, cut-offs, and extensive floodplains are restricted to a short stretch of the mainstream around Vientiane and downstream of Kratie where the river develops alluvial channels that are free of control exerted by the underlying bedrock.

The Mekong basin is not normally considered a seismically active area as much of the basin is underlain by the relatively stable continental block. Nonetheless, the parts of the basin in northern Laos, northern Thailand, Myanmar and China do experience frequent earthquakes and tremors. The magnitude of these earthquakes rarely exceeds 6.5 on the Richter magnitude scale and is unlikely to cause material damage.[28][page needed]

History

 
19th century map showing the Mekong river as the "Mei-Kong" river

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 210 BCE, with Ban Chiang being an excellent example of 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 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 front line between the emergent states of Siam and Tonkin (North Vietnam), with Laos and Cambodia, then on the coast, torn between their influence.

The first European to encounter the Mekong was the Portuguese António 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 Spanish 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 invaded the region in the mid-19th century, capturing Saigon in 1861, and establishing a protectorate over Cambodia in 1863.

The first systematic European 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 and 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 found 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 expelled French from its former colony and defeated US-supported governments.

During the wars in Indochina in the 1970s, a significant quantity of explosives (sometimes, entire barges loaded with military ordnance) sank in the Cambodian section of the Mekong (as well as in the country's other waterways). Besides being a danger for fishermen, unexploded ordnance also creates problems for bridge and irrigation systems construction. As of 2013, Cambodian volunteers are being trained, with the support of the Office of Weapons Removal and Abatement within the US State Department Bureau of Political-Military Affairs, to conduct underwater explosive removal.[29]

The many maps of the river basin produced throughout recorded history reflect the region's changing human geography and politics.[30]

In 1995, Laos, Thailand, Cambodia, and Vietnam established the Mekong River Commission (MRC) to manage and coordinate the use and care of the Mekong. In 1996 China and Myanmar became "dialogue partners" of the MRC and the six countries now work together in a cooperative framework. In 2000, the governments of China, Laos, Thailand and Myanmar signed a Agreement on Commercial Navigation on Lancang-Mekong River among the Governments of the People’s Republic of China, the Lao People’s Democratic Republic, the Union of Myanmar and the Kingdom of Thailand which is the mechanism for cooperation with regard to riverine trade on the upper stretches of the Mekong.[31][32]

Natural history

 
Extirpated from most of its pan-Asian range, Cantor's giant softshell turtle can still be found along a stretch of the Mekong in Cambodia (Khmer called "Kanteay")

The Mekong basin is one of the richest areas of biodiversity in the world. Only the Amazon boasts a higher level of bio-diversity.[2] Biota estimates for the Greater Mekong Subregion (GMS) include 20,000 plant species, 430 mammals, 1,200 birds, 800 reptiles and amphibians,[33] and an estimated 850 freshwater fish species (excluding euryhaline species mainly found in salt or brackish water, as well as introduced species).[34] The most species rich orders among the freshwater fish in the river basin are cypriniforms (377 species) and catfish (92 species).[35]

New species are regularly described from the Mekong. In 2009, 145 species previously unknown to science were described from the region, including 29 fish species, two bird species, 10 reptiles, five mammals, 96 plants, and six amphibians.[36] Between 1997 and 2015, an average of two new species per week were discovered in the region.[37] The Mekong Region contains 16 WWF Global 200 ecoregions, the greatest concentration of ecoregions in mainland Asia.[2]

No other river is home to so many species of very large fish.[38] The biggest include three species of Probarbus barbs, which can grow up to 1.5 m (5 ft) and weigh 70 kg (150 lb),[39] the giant freshwater stingray (Himantura polylepis, syn. H. chaophraya), which can reach at least 5 m (16 ft) in length and 1.9 m (6 ft 3 in) in width,[40] the giant pangasius (Pangasius sanitwongsei), giant barb (Catlocarpio siamensis) and the endemic Mekong giant catfish (Pangasianodon gigas). The last three can grow up to about 3 m (10 ft) in length and weigh 300 kg (660 lb).[38] All of these have declined drastically because of dams, flood control, and overfishing.[38]

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, with only 85 individuals remaining.[41]

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

The endangered Siamese crocodile (Crocodylus siamensis) occurs in small isolated pockets within the northern Cambodian and Laotian portions of the Mekong River. The saltwater crocodile (Crocodylus porosus) once ranged from the Mekong Delta up the river into Tonle Sap and beyond but is now extinct in the river, along with being extinct in all of Vietnam and possibly even Cambodia.

Protected areas

 
Bank erosion on the Song Tien, a Mekong branch, Binh Dai District, Ben Tre Province, Vietnam.

Natural phenomena

The low tide level of the river in Cambodia is lower than the high tide level out at sea, and the flow of the Mekong inverts with the tides throughout its stretch in Vietnam and up to Phnom Penh. The very flat Mekong delta area in Vietnam is thus prone to flooding, especially in the provinces of An Giang and Dong Thap (Đồng Tháp), near the Cambodian border.

Fisheries

 
Fish Farming on Mekong branch, Song Tien, Đồng Tháp Province, Vietnam

Aquatic biodiversity in the Mekong River system is the second highest in the world after the Amazon.[42][43] The Mekong boasts the most concentrated biodiversity per hectare of any river.[44] The largest recorded freshwater fish, a 300 kg giant freshwater stingray in 2022 and previously a 293 kg Mekong giant catfish in 2005, were both caught in the Mekong River.[45]

The commercially valuable fish species in the Mekong are generally divided between "black fish", which inhabit low oxygen, slow moving, shallow waters, and "white fish", which inhabit well oxygenated, fast moving, deeper waters.[46] People living within the Mekong River system generate many other sources of food and income from what are often termed "other aquatic animals" (OAAs) such as freshwater crabs, shrimp, snakes, turtles, and frogs.

OAAs account for about 20% of the total Mekong catch.[2] When fisheries are discussed, catches are typically divided between the wild capture fishery (i.e., fish and other aquatic animals caught in their natural habitat), and aquaculture (fish reared under controlled conditions). Wild capture fisheries play the most important role in supporting livelihoods. Wild capture fisheries are largely open access fisheries, which poor rural people can access for food and income.

Broadly, there are three types of fish habitats in the Mekong: i) the river, including all the main tributaries, rivers in the major flood zone, and the Tonle Sap, which altogether yield about 30% of wild catch landings; ii) rain-fed wetlands outside the river-floodplain zone, including mainly rice paddies in formerly forested areas and usually inundated to about 50 cm, yielding about 66% of wild catch landings; and iii) large water bodies outside the flood zone, including canals and reservoirs yielding about 4% of wild catch landings.[2]

The Mekong Basin has one of the world's largest and most productive inland fisheries.[42][47][48][49] An estimated two million tonnes of fish are landed a year, in addition to almost 500,000 tonnes of other aquatic animals.[50] Aquaculture yields about two million tonnes of fish a year.[46] Hence, the lower Mekong basin yields about 4.5 million tonnes of fish and aquatic products annually. The total economic value of the fishery is between US$3.9 and US$7 billion a year.[2] Wild capture fisheries alone have been valued at US$2 billion a year.[48] This value increases considerably when the multiplier effect is included, but estimates vary widely.

An estimated 2.56 million tonnes of inland fish and other aquatic animals are consumed in the lower Mekong every year.[46] Aquatic resources make up between 47 and 80% of animal protein in rural diets for people who live in the Lower Mekong Basin.[48][51][52] Fish are the cheapest source of animal protein in the region and any decline in the fishery is likely to significantly impact nutrition, especially among the poor.[42][51][53][54] Fish are the staple of the diet in Laos and Cambodia, with around 80% of the Cambodian population's annual protein intake coming from fish caught in the Mekong River system, with no alternative source to replace it. An MRC report claims that dam projects on the Mekong River will reduce aquatic life by 40% by 2020, and predicted that 80% of fish will be depleted by 2040. Thailand will be impacted, as its fish stocks in the Mekong will decline by 55%, Laos will be reduced by 50%, Cambodia by 35%, and Vietnam by 30%.[55]

It is estimated that 40 million rural people, more than two-thirds of the rural population in the lower Mekong basin, are engaged in the wild capture fishery.[2] Fisheries contribute significantly to a diversified livelihood strategy for many people, particularly the poor, who are highly dependent on the river and its resources for their livelihoods.[47][48][52] They provide a principal form of income for numerous people and act as a safety net and coping strategy in times of poor agricultural harvests or other difficulties.[47][48][52] In Laos alone, 71% of rural households (2.9 million people) rely on fisheries for either subsistence or additional cash income. Around the Tonle Sap Lake in Cambodia, more than 1.2 million people live in fishing communes and depend almost entirely on fishing for their livelihoods.[2]

Dams

The Mekong is already heavily dammed, with many more dams planned and under construction, mostly for generating hydropower. China built ten[56] or eleven[57] cascade dams on the Mekong mainstream between 1995 and mid-2019, leaving Vietnam, Laos, Cambodia and Thailand without same amount of water as before investment.[58] China, Laos and Cambodia are planning and/or building more. The Mekong has the fastest-growing hydropower construction of any large river basin worldwide.[59] The Lao Government is aiming to lift the nation out of poverty by making it "the battery of Asia".[60]

Critics fear that China's ability to control the Mekong's flow gives it leverage over downstream nations who rely on China's goodwill. In a worst-case scenario, China could well make demands on thirsty downstream countries who would not be able to refuse. "China could, in short, use its dams to 'weaponize water'".[57]

The Jinghong Dam, as of January 2020 the nearest Chinese dam upstream of the Thai border, has caused huge fluctuations in river levels, affecting people's livelihoods downstream by disrupting the river's natural cycle. It is impacting the ecosystem, disturbing the migratory patterns of fish as well as riverbank plants and local agriculture downstream.[60]

Navigation

 
Mekong ferry, Neak Loeung, Cambodia
 
Slow cruise boats, Pakbeng, Laos

For thousands of years the Mekong River has been an important conduit for people and goods between the many towns on its banks. Traditional forms of trade in small boats linking communities continue today, however the river is also becoming an important link in international trade routes, connecting the six Mekong countries to each other, and also to the rest of the world.[2] The Mekong is still a wild river and navigation conditions vary greatly along its length. Broadly, navigation of the river is divided between upper and lower Mekong, with the "upper" part of the river defined as the stretch north of the Khone Falls in southern Laos and the "lower" part as the stretch below these falls.

Narrower and more turbulent sections of water in the upstream parts of the Mekong River, coupled with large annual water level variations continue to present a challenge to navigation. The seasonal variations in water level directly affect trade in this section of the river. Volumes of trade being shipped decrease by more than 50%, primarily due to the reduced draughts available during the low water season (June–January).[2] Despite these difficulties, the Mekong River is already an important link in the transit chain between Kunming and Bangkok with about 300,000 tonnes of goods shipped via this route each year.[2] The volume of this trade is expected to increase by 8–11% per year. Port infrastructure is being expanded to accommodate the expected growth in traffic, with new facilities planned for Chiang Saen port.[2]

In Laos, 50 and 100 DWT vessels are operated for regional trade. Cargos carried are timber, agricultural products, and construction materials.[2] Thailand imports a wide variety of products from China, including vegetables, fruit, agricultural products, and fertilisers. The main exports from Thailand are dried longan, fish oil, rubber products, and consumables. Nearly all the ships carrying cargo to and from Chiang Saen Port are 300 DWT Chinese flag vessels.[2]

Waterborne trade in the lower Mekong countries of Vietnam and Cambodia has grown significantly, with trends in container traffic at Phnom Penh port and general cargo through Can Tho port both showing steady increases until 2009 when a decrease in cargo volumes can be attributed to the global financial crisis and a subsequent decline in demand for the export of garments to the US.[2] In 2009, Mekong trade received a significant boost with the opening of a new deep-water port at Cai Mep in Vietnam. This new port has generated a renewed focus on the Mekong River as a trade route. The Cai Mep container terminals can accommodate vessels with a draught of 15.2 m, equivalent to the largest container ships in the world. These mother vessels sail directly to Europe or the United States, which means that goods can be shipped internationally to and from Phnom Penh with only a single transshipment at Cai Mep.[2]

As an international river, a number of agreements exist between the countries that share the Mekong to enable trade and passage between them. The most important of these, which address the full length of the river, are:[2]

  • Agreement between China and Lao PDR on Freight and Passenger Transport along the Lancang–Mekong River, adopted in November 1994.
  • Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin, Article 9, Freedom of Navigation, 5 April 1995, Chiang Rai.
  • Hanoi Agreement between Cambodia and Viet Nam on Waterway Transportation, 13 December 1998.
  • Agreement between and among the Governments of the Laos, Thailand, and Vietnam for Facilitation of Cross border Transport of Goods and People, (amended at Yangon, Myanmar), signed in Vientiane, 26 November 1999.
  • Agreement on Commercial Navigation on Lancang–Mekong River among the governments of China, Laos, Myanmar and Thailand, adopted at Tachileik, 20 April 2000.
  • Phnom Penh Agreement between Cambodia and Vietnam on the Transit of Goods, 7 September 2000.
  • New Agreement on Waterway Transportation between Vietnam and Cambodia, signed in Phnom Penh, 17 December 2009.

In December 2016, the Thai cabinet of Prime Minister Prayut Chan-o-cha agreed "in principle" to a plan to dredge stretches of the Mekong and demolish rocky outcrops that are hindrances to easy navigation. The international Lancang-Mekong River navigation improvement plan for 2015–2025, conceived by China, Myanmar, Lao, and Thailand, aims to make the river more navigable for 500-tonne cargo vessels sailing the river from Yunnan to Luang Prabang, a distance of 890 kilometres.[61] China has been the driving force behind the demolition plan as it aims to expand trade in the area.[62] The plan is split into two phases. The first phase, from 2015 to 2020, involves a survey, a design, and an assessment of the environmental and social impacts of the project. These have to be approved by the four countries involved: China, Laos, Myanmar, Thailand. The second phase (2020–2025) involves navigational improvements from Simao in China to 243 border posts in China and Myanmar, a distance of 259 km.[61] Local groups have countered that native inhabitants already operate their boats year-round and that the plan to blast the rapids is not about making life better for local people, but about enabling year-round traffic of large Chinese commercial boats.[63]

On 4 February 2020, the Thai Cabinet voted to stop the project to blast and dredge 97 km of the river bed after Beijing failed to stump up the money for further surveys of the affected area.[64]

Bridges

 
Kizuna Bridge cross Mekong at Kampong Cham

Construction of Myanmar–Laos Friendship Bridge started on 19 February 2013. The bridge will be 691.6 m (2,269 ft) long and have an 8.5 m (28 ft) wide two-lane motorway.[65]

The Thai–Lao Friendship Bridge (Thai: สะพานมิตรภาพ ไทย-ลาว, RTGSSaphan Mittraphap Thai-Lao) connects Nong Khai city with Vientiane in Laos. The 1,170 m-long (3,840 ft) bridge opened on 8 April 1994. It has two 3.5 m-wide (11 ft) lanes with a single railway line in the middle. On 20 March 2004, the Thai and Lao governments agreed to extend the railway to Tha Nalaeng in Laos. This extension has since been completed.

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

The Third Thai–Lao Friendship Bridge opened for traffic on 11 November 2011, connecting Nakhon Phanom Province (Thailand) and Thakhek (Laos), as part of Asian Highway 3. The Chinese and Thai governments agreed to build the bridge and share the estimated US$33 million cost.

The Fourth Thai–Lao Friendship Bridge opened to traffic on 11 December 2013.[66] It links Chiang Rai Province, Thailand with Ban Houayxay, Laos.

There is one bridge over the Mekong entirely within Laos. Unlike the Friendship Bridges, it is not a border crossing. It is at Pakse in Champasak Province. It is 1,380 m (4,528 ft) long, and was completed in 2000. 15°6′19.95″N 105°48′49.51″E / 15.1055417°N 105.8137528°E / 15.1055417; 105.8137528 (Pakxe)).

The Kizuna Bridge is in Cambodia, in the city of Kampong Cham, on the road linking Phnom Penh with the remote provinces of Ratanakiri and Mondolkiri, and Laos. The bridge opened for traffic on 11 December 2001.

The Prek Tamak Bridge, 40 km (25 mi) north of Phnom Penh opened in 2010.

Phnom Penh itself has no bridge under construction yet, although two new bridges have recently opened on the Tonle Sap, and the main bridge on the highway to Ho Chi Minh was duplicated in 2010.

Another new bridge was built at Neak Leung on the Phnom Penh to Ho Chi Minh Highway 1 with Japanese government assistance, and opened in 2015.

In Vietnam, since the year 2000 Mỹ Thuận Bridge crosses the first channel—the left, main branch of the Mekong, the Sông Tiền or Tiền Giang—near Vĩnh Long and since 2008 Rạch Miễu Bridge crosses it near Mỹ Tho, between the provinces of Tiền Giang and Bến Tre.

Cần Thơ Bridge crosses the second channel—the right, main distributary of the Mekong, the Bassac (Song Hau). Inaugurated in 2010, it is the longest main span cable-stayed bridge in Southeast Asia.

Environmental issues

Drought linked to a changing climate and dozens of hydroelectric dams are damaging the Mekong ecosystem.[67][68][69] When drought ends and the inevitable floods begin, the effects of Mekong dams on flood pulse dynamics over the entire Lower Mekong are poorly understood.[70]

Sewage treatment is rudimentary in towns and urban areas throughout much of the Mekong's length, such as Vientiane in Laos. Water pollution impacts the river's ecological integrity as a result.[citation needed]

Much of the 8.3 billion tonnes of plastic present on earth[71] makes its way to the oceans. Ninety percent of plastic in the oceans is flushed there by just 10 rivers. The Mekong is one of them.[72]

A growing number of academics, NGOs, and scientists have urged the international community and the Mekong River Commission to reduce the use of hydropower, giving concerns of long-term sustainability. Some of them have urged an immediate moratorium on new construction of hydropower projects and a shift to solar and other forms of renewable energy, which are becoming more competitive and faster to install.[73]

See also

References

  1. ^ a b S. Liu; P. Lu; D. Liu; P. Jin; W. Wang (2009). "Pinpointing source and measuring the lengths of the principal rivers of the world". International Journal of Digital Earth. 2 (1): 80–87. Bibcode:2009IJDE....2...80L. doi:10.1080/17538940902746082. S2CID 27548511.
  2. ^ a b c d e f g h i j k l m n o p q r s t u "State of the Basin Report, 2010" (PDF). Mekong River Commission. Vientiane. 2010.
  3. ^ Sasipornkarn, Emmy (16 August 2019). "A dam-building race threatens the Mekong River". Deutsche Welle. Retrieved 18 August 2019.
  4. ^ Sripiachai, Pattanapong (29 October 2019). "Mekong River falls to critical level, sand dunes emerge". Bangkok Post. Retrieved 26 November 2019.
  5. ^ Beech, Hannah (13 April 2020). "China Limited the Mekong's Flow. Other Countries Suffered a Drought". The New York Times. ISSN 0362-4331. Retrieved 14 April 2020.
  6. ^ Nguyen Thi Dieu (1999), The Mekong River and the Struggle for Indochina: Water, War, and Peace, Westport: Praeger, p. 36, ISBN 9780275961374
  7. ^ Baxter-Sagart.
  8. ^ Reid, H. (1857). A System of Modern Geography ... with Exercises of examination. To which are added treatises on Astronomy and Physical Geography. United Kingdom: (n.p.).
  9. ^ Universal Gazetteer of the World: A Dictionary, Geographical, Historical and Statistical, of the Various Kingdoms, States, Provinces, Cities, Towns, Forts, Harbors, Rivers, Lakes, Seas, Mountains, &c., in the World ... Also the Census of 1850. (1852). United States: Z. & B. F. Pratt.
  10. ^ A Gazetteer of the World: Brazil–Derry. (1856). United Kingdom: A. Fullarton.
  11. ^ Roberts, G. (1834). The Elements of Modern Geography and General History, on a Plan Entirely New ... New Edition ... Improved, Etc. United Kingdom: (n.p.).
  12. ^ Hamilton, W. (1815). The East India Gazetteer: Containing Particular Descriptions of the Empires, Kingdoms, Principalities, Provinces, Cities, Towns, Districts, Fortresses, Harbours, Rivers, Lakes, &c. of Hindostan, and the Adjacent Countries, India Beyond the Ganges, and the Eastern Archipelago; Together with Sketches of the Manners, Customs, Institutions, Agriculture, Commerce, Manufactures, Revenues, Population, Castes, Religion, History, &c. of Their Various Inhabitants. United Kingdom: J. Murray.
  13. ^ Wangkiat, Paritta (15 January 2017). "Against the flow". Bangkok Post. No. Spectrum. Retrieved 3 May 2018.
  14. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab Mekong River Commission (2005). (PDF). MRC, Vientiane, Laos. Archived from the original (PDF) on 13 July 2018. Retrieved 21 April 2012.
  15. ^ G. Lacombe; A. Pierret; C. T. Hoanh; O. Sengtaheuanghoung; A. Noble (2010). "Conflict, migration and land-cover changes in Indochina: a hydrological assessment". Ecohydrology. 3 (4): 382–391. doi:10.1002/eco.166. S2CID 131563940.
  16. ^ Michael Buckley (30 March 2015). "The Price of Damming Tibet's Rivers". The New York Times. p. A25. from the original on 31 March 2015. Retrieved 1 April 2015. Other plans call for diversion of water from the Brahmaputra, Salween and Mekong – all rivers that cross national boundaries.
  17. ^ Yeophantong, Pichamon (2014). "China's Lancang Dam Cascade and Transnational Activism in the Mekong Region: Who's Got the Power?". Asian Survey. 54 (4): 700–724. doi:10.1525/as.2014.54.4.700.
  18. ^ "Mekong River in Golden Triangle drops to lowest level in a century". Thai PBS. 20 July 2019. Retrieved 21 July 2019.
  19. ^ M. Clark; L. Schoenbohm; L. Royden; K. Whipple; B. Burchfiel; W. Zhang; W. Tang; E. Wang; L. Chen (2004). "Surface uplift, tectonics, and erosion of eastern Tibet from large-scale drainage patterns". Tectonics. 23 (TC1006): 227–234. Bibcode:2004Tecto..23.1006C. doi:10.1029/2002TC001402.
  20. ^ C. Twidale (2004). "River patterns and their meanings". Earth-Science Reviews. 67 (3–4): 159–218. Bibcode:2004ESRv...67..159T. doi:10.1016/j.earscirev.2004.03.001.
  21. ^ S. K. Tandon & R. Sinha (2007). "Geology of large river systems". In A. Gupta (ed.). Large rivers: geomorphology and management. London: John Wiley & Sons. pp. 7–28. ISBN 978-0-470-84987-3.
  22. ^ P. D. Clift & A. R. Plumb (2008). The Asian monsoon: causes, history, and effects. Cambridge, UK: Cambridge University Press. ISBN 9780521847995.
  23. ^ P. D. Clift; A. Carter; I. H. Campbell; M. Pringle; V. Nguyen; C. Allen; C. M. Allen; K. V. Hodges; T. T Mai (2006). "Thermochronology of mineral grains in the Red and Mekong Rivers, Viet Nam: Provenance and exhumation implications for Southeast Asia" (PDF). Geochemistry, Geophysics, Geosystems. 7 (10): 1–28. Bibcode:2006GGG.....710005C. doi:10.1029/2006GC001336.
  24. ^ P. D. Clift, G. Layne & J. Blusztajn (2004). "Marine sedimentary evidence for monsoon strengthening, Tibetan uplift, and drainage evolution in East Asia". Geophysical Monograph Series. 149 (2004): 255–282. Bibcode:2004GMS...149..255C. doi:10.1029/149GM14. ISBN 0-87590-414-9.
  25. ^ a b T. Tamura; Y. Saito; S. Sotham; B. Bunnarin; K. Meng; S. Im; S. Choup; F. Akiba (2009). "Initiation of the Mekong River Delta at 8 ka: Evidence from the sedimentary succession in the Cambodian lowland". Quaternary Science Reviews. 28 (3–4): 327–344. Bibcode:2009QSRv...28..327T. doi:10.1016/j.quascirev.2008.10.010.
  26. ^ D. Penny (2006). "The Holocene history and development of the Tonle Sap, Cambodia". Quaternary Science Reviews. 25 (3–4): 310–322. Bibcode:2006QSRv...25..310P. doi:10.1016/j.quascirev.2005.03.012.
  27. ^ T. K. Ta; V. L. Nguyen; M. Tateishi; I. Kobayashi; S. Tanabe; Y. Saito (2002). "Holocene delta evolution and sediment discharge of the Mekong River, Southern Viet Nam". Quaternary Science Reviews. 21 (16–17): 1807–1819. Bibcode:2002QSRv...21.1807T. doi:10.1016/S0277-3791(02)00007-0.
  28. ^ C. H. Fenton, P. Charusiri & S. H. Wood (2003). "Recent paleoseismic investigations in northern and western Thailand". Annals of Geophysics. 46 (5): 957–981. hdl:2122/998.
  29. ^ Cambodia: Demining in the depths 25 March 2013 at the Wayback Machine. Denise Hruby, 24 March 2013
  30. ^ Romanos, Christoforos (2023). Liquid Territories : configurations of geographic space in the cartographic projections of the Mekong River’s catchment areas. Delft: Delft University of Technology. p. 325.
  31. ^ Lazarus, K.; Dubeau, P.; Bambaradeniya, C.; Friend, R.; Sylavong, L. (2006). "Increasing pace of change" (PDF). An Uncertain Future: Biodiversity and Livelihoods Along the Mekong River in Northern Lao PDR. Bangkok, Thailand and Gland, Switzerland: The World Conservation Union (IUCN). pp. 21–24. ISBN 978-2-8317-0956-7. Retrieved 21 August 2019.
  32. ^ (PDF). JCCN. 20 April 2000. Archived from the original (PDF) on 21 August 2019. Retrieved 21 August 2019.
  33. ^ C. Thompson (2008). "First Contact in the Greater Mekong" (PDF). WWF Greater Mekong Program.[permanent dead link]
  34. ^ K. G. Hortle (2009). . Catch and Culture. Mekong River Commission. Archived from the original on 30 July 2012.
  35. ^ Valbo-Jørgensen, J; Coates, D.; and Hortle, K. (2009). Fish diversity in the Mekong River basin. pp. 161–196 in: Campbell, I.C. (editor). The Mekong – Biophysical Environment of an International River Basin, 1st edition. Academic Press, Elsevier. ISBN 978-0-12-374026-7
  36. ^ N. Gephart; G. Blate; C. McQuistan; C. Thompson (2010). "New Blood: Greater Mekong New Species Discoveries, 2009" (PDF). WWF.
  37. ^ "163 new species, including 'Klingon Newt', discovered". Fox News. 20 December 2016. Retrieved 20 December 2016.
  38. ^ a b c "River of Giants: Giant Fish of the Mekong" (PDF). WWF Greater Mekong Program. 2012.
  39. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). Species of Probarbus in FishBase. February 2017 version.
  40. ^ Last, P.R.; Compagno, L.J.V. (1999). "Myliobatiformes: Dasyatidae". In Carpenter, K.E.; Niem, V.H. (eds.). FAO identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Food and Agriculture Organization of the United Nations. pp. 1479–1505. ISBN 92-5-104302-7.
  41. ^ Ryan, Gerard Edward; Dove, Verne; Trujillo, Fernando; Doherty, Paul F. (2011). "Irrawaddy dolphin demography in the Mekong River: an application of mark–resight models". Ecosphere. 2 (5): art58. doi:10.1890/ES10-00171.1.
  42. ^ a b c International Center for Environmental Management (2010). "Strategic Environmental Assessment (SEA) of hydropower on the Mekong mainstream" (PDF). Mekong River Commission.
  43. ^ J.W. Ferguson; M. Healey; P. Dugan; C. Barlow (2011). "Potential Effects of Dams on Migratory Fish in the Mekong River: Lessons from the Fraser and Columbia Rivers". Environmental Management. 47 (1): 141–159. Bibcode:2011EnMan..47..141F. doi:10.1007/s00267-010-9563-6. PMID 20924582. S2CID 19900859.
  44. ^ J. Valbo-Jørgensen, D. Coates & K.G. Hortle (2009). "Fish diversity in the Mekong River Basin.". In I.C. Campbell (ed.). The Mekong: Biophysical Environment of an International River Basin. London: Elsevier Publishers. pp. 161–196. ISBN 978-0123740267.
  45. ^ "Largest freshwater fish ever recorded caught in Cambodia". the Guardian. Associated Press. 20 June 2022. Retrieved 20 June 2022.
  46. ^ a b c Mekong River Commission (2010). "Assessment of Basin-wide Development Scenarios: Technical Note 11: Impacts on Fisheries" (PDF). Mekong River Commission.[permanent dead link]
  47. ^ a b c E. Baran & C. Myschowoda (2009). "Dams and fisheries in the Mekong Basin". Aquatic Ecosystem Health and Management. 12 (3): 227–234. doi:10.1080/14634980903149902. S2CID 85279301.
  48. ^ a b c d e E. Baran & B. Ratner (2007). (PDF). Science Brief. World Fish Center. Archived from the original (PDF) on 9 May 2013. Retrieved 12 October 2012.
  49. ^ J. Sarkkula, M. Keskinen, J. Koponen, M. Kummu, J. E. Richery & O. Varis (2009). "Hydropower in the Mekong Region: What Are the Likely Impacts Upon Fisheries?". In F. Molle; T. Foran; M. Käkönen (eds.). Contested Waterscapes in the Mekong Region: Hydropower, Livelihoods and Governance. London: Earthscan. pp. 227–249. ISBN 978-1-84407-707-6.{{cite book}}: CS1 maint: multiple names: authors list (link)
  50. ^ K. G. Hortle (2007). "Consumption and the yield of fish and other aquatic animals from the Lower Mekong Basin" (PDF). MRC Technical Paper No. 16. Mekong River Commission.
  51. ^ a b S. Bush (2007). "Give a man a fish..." Contextualising Living Aquatic Resources Development in the Lower Mekong Basin" (PDF). AMRC Working Papers 8. Australian Mekong Resource Centre, University of Sydney.
  52. ^ a b c R. Friend & D. J. H. Blake (2009). "Negotiating trade-offs in water resources development in the Mekong Basin: implications for fisheries and fishery-based livelihoods". Water Policy. 11 (S1): 13–30. doi:10.2166/wp.2009.001.
  53. ^ I. G. Baird (2009). "The Don Sahong Dam: Potential Impacts on Regional Fish Migrations, Livelihoods and Human Health" (PDF). POLIS Project on Environmental Governance, University of Victoria.[permanent dead link]
  54. ^ I. G. Baird (2011). "The Don Sahong Dam". Critical Asian Studies. 43 (2): 211–235. doi:10.1080/14672715.2011.570567. S2CID 55168234.
  55. ^ Wipatayotin, Apinya (20 July 2019). "Dam tests spark crisis". Bangkok Post. Retrieved 20 July 2019.
  56. ^ "Dam disaster on the way" (Opinion). Bangkok Post. 20 July 2019. Retrieved 20 July 2019.
  57. ^ a b Chellaney, Brahma (2 August 2019). "Damming the Mekong Basin to Environmental Hell" (Opinion). Project Syndicate. Retrieved 5 August 2019.
  58. ^ "China's dams exacerbated extreme drought in lower Mekong: Study". Al Jazeera. 25 April 2020.
  59. ^ "Requiem for a river". The Economist. Retrieved 18 February 2016.
  60. ^ a b Bainbridge, Amy; Vimonsuk, Supattra (20 January 2020). "Chinese dams are 'exacerbating' Mekong River drought, and locals say they've never seen it this low". ABC News. Australian Broadcasting Corporation. Retrieved 20 January 2020.
  61. ^ a b Suksamran, Nauvarat (9 January 2017). "Locals slam Mekong blasting plan". Bangkok Post. Retrieved 9 January 2017.
  62. ^ "Spare the Mekong" (Opinion). Bangkok Post. 30 December 2016. Retrieved 30 December 2016.
  63. ^ Roykaew, Niwat (17 July 2019). "China must be sincere on Mekong" (Opinion). Bangkok Post. Retrieved 20 July 2019.
  64. ^ "Thais ditch China-led plan to dredge Mekong". The Straits Times. 6 February 2020. Retrieved 6 February 2020.
  65. ^ . Archived from the original on 25 February 2013. Retrieved 17 March 2013.
  66. ^ . Archived from the original on 29 December 2012. Retrieved 17 March 2013.
  67. ^ Sasipornkarn, Emmy (16 August 2019). "A dam-building race threatens the Mekong River". Deutsche Welle. Retrieved 18 August 2019.
  68. ^ Sripiachai, Pattanapong (29 October 2019). "Mekong River falls to critical level, sand dunes emerge". Bangkok Post. Retrieved 26 November 2019.
  69. ^ Beech, Hannah (13 April 2020). "China Limited the Mekong's Flow. Other Countries Suffered a Drought". The New York Times. ISSN 0362-4331. Retrieved 14 April 2020.
  70. ^ Pokhrel, Yadu; et al. (10 December 2018). "Potential Disruption of Flood Dynamics in the Lower Mekong River Basin Due to Upstream Flow Regulation". Scientific Reports. 8 (17767): 17767. Bibcode:2018NatSR...817767P. doi:10.1038/s41598-018-35823-4. PMC 6288158. PMID 30532063.
  71. ^ Franzen, Harald (20 July 2017). "There are 8.3 billion tons of plastic in the world". Deutsche Welle. Retrieved 17 April 2018.
  72. ^ Franzen, Harald (30 November 2017). "Almost all plastic in the ocean comes from just 10 rivers". Deutsche Welle. Retrieved 17 April 2018.
  73. ^ Fawthrop, Tom (28 November 2019). "Dams and Climate Change Kill the Mekong". YaleGlobal Online. Yale University. Retrieved 26 November 2019.

Further reading

  • Kuenzer, C., I. Campbell, M. Roch, P. Leinenkugel, V. Q. Tuan and S. Dech (2012): Understanding the impact of hydropower developments in the context of upstream–downstream relations in the Mekong river basin. In: Sustainability Science 8 (4), pp. 565–584. DOI: 10.1007/s11625-012-0195-z.
  • Kuenzer, C., H. Guo, J. Huth, P. Leinenkugel, X. Li and S. Dech (2013): Flood Mapping and Flood Dynamics of the Mekong Delta. ENVISAT-ASAR-WSM Based Time-Series Analyses. In: Remote Sensing 5, pp. 687–715. DOI: 10.3390/rs5020687.
  • Leinenkugel, P., C. Kuenzer, N. Oppelt and S. Dech (2013): Characterisation of land surface phenology and land cover based on moderate resolution satellite data in cloud prone areas – A novel product for the Mekong Basin. In: Remote Sensing of Environment 136, pp. 180–198. DOI: 10.1016/j.rse.2013.05.004.
  • Moder, F., C. Kuenzer, Z. Xu, P. Leinenkugel and Q. Bui Van (2012): IWRM for the Mekong Basin. In: Renaud, F. G. and C. Kuenzer (eds.): The Mekong Delta System. Interdisciplinary Analyses of a River Delta. Dordrecht: Springer, pp. 133–166.
  • Renaud, F. G. und C. Kuenzer (2012): The Mekong Delta System. Interdisciplinary Analyses of a River Delta (= Springer Environmental Science and Engineering). Dordrecht: Springer. ISBN 978-94-007-3961-1.
  • Kuenzer, C. and F. G. Renaud (2012): Climate Change and Environmental Change in River Deltas Globally. In: Renaud, F. G. and C. Kuenzer (eds.): The Mekong Delta System. Interdisciplinary Analyses of a River Delta. Dordrecht: Springer, pp. 7–48.
  • Kuenzer, C. (2014): Remote Sensing the Mekong. In: International Journal of Remote Sensing 35 (8), pp. 2747–2751. DOI: 10.1080/01431161.2014.890377.
  • Kuenzer, C., P. Leinenkugel, M. Vollmuth and S. Dech (2014): Comparing global land-cover products – implications for geoscience applications: an investigation for the trans-boundary Mekong Basin. In: International Journal of Remote Sensing 35 (8), pp. 2752–2779. DOI: 10.1080/01431161.2014.890305.
  • Shoemaker, Bruce; Robichaud, William, eds. (November 2019). Dead in the Water; Global Lessons from the World Bank's Model Hydropower Project in Laos (Paper ed.). Madison: University of Wisconsin Press. ISBN 9780299317942. Retrieved 26 November 2019.

External links

Map all coordinates using: OpenStreetMap 
Download coordinates as: KML
  • The WISDOM Project, a Water related Information System for the Mekong Delta
  • Mekong River Commission
  • CGIAR Research Program on Water, Land and Ecosystems - Greater Mekong 9 July 2021 at the Wayback Machine
  • Countries of the Mekong River: The Greater Mekong Subregion Asian Development Bank
  • Rivers Network : Mekong river blog 5 November 2018 at the Wayback Machine

mekong, river, trans, boundary, river, east, asia, southeast, asia, world, twelfth, longest, river, third, longest, asia, estimated, length, drains, area, discharging, water, annually, from, tibetan, plateau, river, runs, through, china, myanmar, laos, thailan. The Mekong or Mekong River is a trans boundary river in East Asia and Southeast Asia It is the world s twelfth longest river and the third longest in Asia 1 Its estimated length is 4 909 km 3 050 mi 1 and it drains an area of 795 000 km2 307 000 sq mi discharging 475 km3 114 cu mi of water annually 2 From the Tibetan Plateau the river runs through China Myanmar Laos Thailand Cambodia and Vietnam The extreme seasonal variations in flow and the presence of rapids and waterfalls in the Mekong make navigation difficult Even so the river is a major trade route between western China and Southeast Asia The construction of hydroelectric dams along the Mekong in recent decades causes serious problems for the river s ecosystem including the exacerbation of drought 3 4 5 Mekong River湄公河 Meigōng He 澜沧江 Lancang Jiang မ ခ င မ စ Megaung Myit ແມ ນ ຳຂອງ Maenam Khong aemnaokhng Maenam Khong ទន ល ម គង គ Tonle Mekongk Song Me Kong Song Cửu Long 九龍 Mekong River Luang Prabang LaosMekong River watershedLocationCountryChina Myanmar Laos Thailand Cambodia VietnamPhysical characteristicsSourceLasaigongma 拉赛贡玛 Spring locationMt Guozongmucha 果宗木查 Zadoi Yushu Tibetan Autonomous Prefecture Qinghai China coordinates33 42 5 N 94 41 7 E 33 7083 N 94 6950 E 33 7083 94 6950 elevation5 224 m 17 139 ft MouthMekong Delta locationVietnam coordinates10 11 N 106 45 E 10 19 N 106 75 E 10 19 106 75 Coordinates 10 11 N 106 45 E 10 19 N 106 75 E 10 19 106 75 elevation0 m 0 ft Length4 350 km 2 700 mi Basin size795 000 km2 307 000 sq mi Discharge locationMekong Delta South China Sea average16 000 m3 s 570 000 cu ft s minimum1 400 m3 s 49 000 cu ft s maximum39 000 m3 s 1 400 000 cu ft s Basin featuresTributaries leftSrepok Nam Khan Tha Nam Ou rightMun Tonle Sap Kok RuakThis article contains Tibetan script Without proper rendering support you may see very small fonts misplaced vowels or missing conjuncts instead of Tibetan characters This article contains Lao text Without proper rendering support you may see question marks boxes or other symbols instead of Lao script This article contains Khmer text Without proper rendering support you may see question marks boxes or other symbols instead of Khmer script This article contains Burmese script Without proper rendering support you may see question marks boxes or other symbols instead of Burmese script Contents 1 Names 2 Course 3 Drainage basin 3 1 Upper basin 3 2 Lower basin 3 3 Water flow along its course 4 Geology 5 History 6 Natural history 6 1 Protected areas 6 2 Natural phenomena 7 Fisheries 8 Dams 9 Navigation 10 Bridges 11 Environmental issues 12 See also 13 References 14 Further reading 15 External linksNames EditThe Mekong was originally called Mae Nam Khong from a contracted form of Tai shortened to Mae Khong 6 In Thai and Lao Mae Nam Mother of Water s is used for large rivers and Khong is the proper name referred to as River Khong However Khong is an archaic word meaning river loaned from Austroasiatic languages such as Vietnamese song from krong and Mon kruŋ river which led to Chinese 江 whose Old Chinese pronunciation has been reconstructed as kˤroŋ 7 and which long served as the proper name of the Yangtze before becoming a generic word for major rivers To the early European traders the Mekong River was also known as Mekon River May Kiang River and Cambodia River 8 9 10 11 12 The local names for the river include From Tai Thai aemnaokhng mɛ ː naːm kʰǒːŋ or just aemokhng mɛ ː kʰǒːŋ Lao ແມ ນ ຳຂອງ mɛː naːm kʰɔːŋ ນ ຳຂອງ naːm kʰɔːŋ Tai Lue naaemkhxng naːm mɛː kʰɔ ːŋ nakhxng naːm kʰɔ ːŋ Khmer ម គង គ Mekongk meːkɔŋ ទន ល ម គង គ Tonle Mekongk tɔnlei meikɔŋ Burmese မ ခ င မ စ IPA mɛ ɡaʊɰ mjɪ ʔ Shan ၼမ ၶ င nam kʰɔ ŋ or ၼမ မ ၶ င nam mɛ kʰɔ ŋ Chinese 湄公河 Meigōng he Vietnamese Song Me Kong IPA ʂe wŋm me ke wŋm Other Vietnamese Song Cửu Long 九龍 Nine Dragons River ʂe wŋm kɨ w lawŋm Khmer ទន ល ធ Tonle Thum tɔnlei tʰum lit Big River or Great River Khmuic ŏ m kʰrɔːŋ ŏ m means river or water here it means river kʰrɔːŋ means canal So ŏ m kʰrɔːŋ means canal river In the ancient time Khmuic people called it ŏ m kʰrɔːŋ ɲă k or ŏ m kʰrɔːŋ ɟru ːʔ which means giant canal river or deep canal river respectively Course EditThe Mekong rises as the Za Qu Tibetan ར ཆ Wylie rDza chu ZYPY Za qu Chinese 扎曲 pinyin Za Qu and soon becomes known as the Lancang simplified Chinese 澜沧江 traditional Chinese 瀾滄江 pinyin Lancang Jiang from the old name of Lao kingdom Lan Xang the characters may also be literally understood as turbulent green river It originates in the three rivers source area on the Tibetan Plateau in the Sanjiangyuan National Nature Reserve The reserve protects the headwaters of from north to south the Yellow Huang He the Yangtze and the Mekong Rivers 2 It flows through the Tibetan Autonomous Region and then southeast into Yunnan Province and then the Three Parallel Rivers Area in the Hengduan Mountains along with the Yangtze to its east and the Salween River Nu Jiang in Chinese to its west Then the Mekong meets the China Myanmar border and flows about 10 km 6 2 mi along that border until it reaches the tripoint of China Myanmar and Laos From there it flows southwest and forms the border of Myanmar and Laos for about 100 km 62 mi until it arrives at the tripoint of Myanmar Laos and Thailand This is also the point of confluence between the Ruak River which follows the Thai Myanmar border and the Mekong The area of this tripoint is sometimes termed the Golden Triangle although the term also refers to the much larger area of those three countries that was notorious as a drug producing region From the Golden Triangle tripoint the Mekong turns southeast to briefly form the border of Laos with Thailand Khon Pi Long is a series of rapids along a 1 6 kilometre section of the Mekong River dividing Chiang Rai and Bokeo Province in Laos The name of the rapids means where the ghost lost its way 13 It then turns east into the interior of Laos flowing first east and then south for some 400 km 250 mi before meeting the border with Thailand again Once more it defines the Laos Thailand border for some 850 km 530 mi as it flows first east passing the capital of Laos Vientiane then turns south A second time the river leaves the border and flows east into Laos soon passing the city of Pakse Thereafter it turns and runs more or less directly south crossing into Cambodia At Phnom Penh the river is joined on the right bank by the river and lake system the Tonle Sap When the Mekong is low the Tonle Sap is a tributary water flows from the lake and river into the Mekong When the Mekong floods the flow reverses the floodwaters of the Mekong flow up the Tonle Sap Immediately after the Sap River joins the Mekong by Phnom Penh the Bassac River branches off the right west bank The Bassac River is the first and main distributary of the Mekong This is the beginning of the Mekong Delta The two rivers the Bassac to the west and the Mekong to the east enter Vietnam shortly after this In Vietnam the Bassac is called the Hậu River Song Hậu or Hậu Giang the main eastern branch of the Mekong is called the Tiền River or Tiền Giang In Vietnam distributaries of the eastern main Mekong branch include the Mỹ Tho River the Ba Lai River the Ham Luong River and the Cổ Chien River Drainage basin Edit Mekong River south of Chamdo The Mekong from Phou si The confluence of the Mekong and the Nam Ou Rivers Laos The Mekong Basin can be divided into two parts the upper Mekong basin in Tibet and the lower Mekong basin from Yunnan downstream from China to the South China Sea 14 From the point where it rises to its mouth the most precipitous drop in the Mekong occurs in the upper Mekong basin a stretch of some 2 200 km 1 400 mi Here it drops 4 500 m 14 800 ft before it enters the lower basin where the borders of Thailand Laos China and Myanmar come together in the Golden Triangle Downstream from the Golden Triangle the river flows for a further 2 600 km 1 600 mi through Laos Thailand and Cambodia before entering the South China Sea via a complex delta system in Vietnam 14 Upper basin Edit The upper basin makes up 24 of the total area and contributes 15 20 of the water that flows into the Mekong River The catchment here is steep and narrow Soil erosion has been a major problem and approximately 50 of the sediment in the river comes from the upper basin In Yunnan Province in China the river and its tributaries are confined by narrow deep gorges The tributary river systems in this part of the basin are small Only 14 have catchment areas that exceed 1 000 km2 390 sq mi yet the greatest amount of loss of forest cover in the entire river system per square kilometer has occurred in this region due to heavy unchecked demand for natural resources In the south of Yunnan in Simao and Xishuangbanna Prefectures the river changes as the valley opens out the floodplain becomes wider and the river becomes wider and slower Lower basin Edit Major tributary systems develop in the lower basin These systems can be separated into two groups tributaries that contribute to the major wet season flows and tributaries that drain low relief regions of lower rainfall The first group are left bank tributaries that drain the high rainfall areas of Laos The second group are those on the right bank mainly the Mun and Chi Rivers that drain a large part of northeast Thailand Laos lies almost entirely within the lower Mekong basin Its climate landscape and land use are the major factors shaping the hydrology of the river The mountainous landscape means that only 16 of the country is farmed under lowland terrace or upland shifting cultivation 14 With upland shifting agriculture slash and burn soils recover within 10 to 20 years but the vegetation does not Shifting cultivation is common in the uplands of northern Laos and is reported to account for as much as 27 of the total land under rice cultivation 14 As elsewhere in the basin forest cover has been steadily reduced during the last three decades by shifting agriculture and permanent agriculture The cumulative impacts of these activities on the river regime have not been measured However the hydrological impacts of land cover changes induced by the Vietnam War were quantified in two sub catchments of the lower Mekong River basin 15 Loss of forest cover in the Thai areas of the lower basin has been the highest of all the lower Mekong countries over the past 60 years On the Khorat Plateau which includes the Mun and Chi tributary systems forest cover was reduced from 42 in 1961 to 13 in 1993 14 Although this part of northeast Thailand has an annual rainfall of more than 1 000 mm a high evaporation rate means it is classified as a semi arid region Consequently although the Mun and Chi basins drain 15 of the entire Mekong basin they only contribute 6 of the average annual flow 14 Sandy and saline soils are the most common soil types which makes much of the land unsuitable for wet rice cultivation In spite of poor fertility however agriculture is intensive Glutinous rice maize and cassava are the principal crops 14 Drought is by far the major hydrological hazard in this region 14 Floating homes on the Mekong Cambodia As the Mekong enters Cambodia over 95 of its flows have already joined the river 14 From here on downstream the terrain is flat and water levels rather than flow volumes determine the movement of water across the landscape The seasonal cycle of changing water levels at Phnom Penh results in the unique flow reversal of water into and out of the Great Lake via the Tonle Sap River Phnom Penh also marks the beginning of the delta system of the Mekong River Here the mainstream begins to break up into an increasing number of branches 14 In Cambodia wet rice is the main crop and is grown on the flood plains of the Tonle Sap Mekong and Bassac the Mekong delta distributary known as the Hậu in Vietnam Rivers 14 More than half of Cambodia remains covered with mixed evergreen and deciduous broadleaf forest but forest cover has decreased from 73 in 1973 to 63 in 1993 14 Here the river landscape is flat Small changes in water level determine the direction of water movement including the large scale reversal of flow into and out of the Tonle Sap basin from the Mekong River 14 Mekong Delta Vietnam The Mekong delta in Vietnam is farmed intensively and has little natural vegetation left Forest cover is less than 10 In the Central Highlands of Vietnam forest cover was reduced from over 95 in the 1950s to around 50 in the mid 1990s 14 Agricultural expansion and population pressure are the major reasons for land use and landscape change Both drought and flood are common hazards in the Delta which many people believe is the most sensitive to upstream hydrological change 14 Water flow along its course Edit Table 1 Country share of Mekong River Basin MRB and water flows 14 China Myanmar Laos Thailand Cambodia Vietnam TotalBasin area km2 165 000 24 000 202 000 184 000 155 000 65 000 795 000Catchment as of MRB 21 3 25 23 20 8 100Flow as of MRB 16 2 35 18 18 11 100By taking into account hydrological regimes physiography land use and existing planned and potential resource developments the Mekong is divided into six distinct reaches 14 The Mekong in Laos Reach 1 Lancang Jiang or Upper Mekong River in China In this part of the river the major source of water flowing into the river comes from melting snow on the Tibetan plateau This volume of water is sometimes called the Yunnan component and plays an important role in the low flow hydrology of the lower mainstream Even as far downstream as Kratie the Yunnan component makes up almost 30 of the average dry season flow A major concern is that the ongoing and planned expansion of dams and reservoirs on the Mekong mainstream in Yunnan could have a significant effect on the low flow regime of the lower Mekong basin system 14 16 17 Reach 2 Chiang Saen to Vientiane and Nong Khai This reach is almost entirely mountainous and covered with natural forest although there has been widespread slash and burn agriculture Although this reach cannot be termed unspoiled the hydrological response is perhaps the most natural and undisturbed of all the lower basin Many hydrological aspects of the lower basin start to change rapidly at the downstream boundary of this reach 14 On 19 July 2019 this reach of the river dropped to its lowest level in a century Officials are particularly concerned as July is in the wet season when mainstream flows are abundant historically Locals are blaming low water on the newly constructed Xayaburi Dam as it enters its test phase prior to the start of commercial operation in October 2019 18 Reach 3 Vientiane and Nong Khai to Pakse The boundary between Reach 2 and 3 is where the Mekong hydrology starts to change Reach 2 is dominated in both wet and dry seasons by the Yunnan Component Reach 3 is increasingly influenced by contributions from the large left bank tributaries in Laos namely the Nam Ngum Nam Theun Nam Hinboun Se Bang Fai Se Bang Hieng and Se Done Rivers The Mun Chi river system from the right bank in Thailand enters the mainstream within this reach 14 Reach 4 Pakse to Kratie The main hydrological contributions to the mainstream in this reach come from the Se Kong Se San and Sre Pok catchments Together these rivers make up the largest hydrological sub component of the lower basin Over 25 of the mean annual flow volume to the mainstream at Kratie comes from these three river basins They are the key element in the hydrology of this part of the system especially to the Tonle Sap flow reversal 14 Reach 5 Kratie to Phnom Penh This reach includes the hydraulic complexities of the Cambodian floodplain the Tonle Sap and the Great Lake By this stage over 95 of the total flow has entered the Mekong system The focus turns from hydrology and water discharge to the assessment of water level over bank storage and flooding and the hydrodynamics that determine the timing duration and volume of the seasonal flow reversal into and out of the Great Lake 14 Reach 6 Phnom Penh to the South China Sea Here the mainstream divides into a complex and increasingly controlled and artificial system of branches and canals Key features of flow behaviour are tidal influences and salt water intrusion Every year 35 50 of this reach is flooded during the rainy season The impact of road embankments and similar infrastructure developments on the movement of this flood water is an increasingly important consequence of development 14 Table 2 summarises the mean annual flows along the mainstream The mean annual flow entering the lower Mekong from China is equivalent to a relatively modest 450 mm depth of runoff Downstream of Vientiane this increases to over 600 mm as the principal left bank tributaries enter the mainstream mainly the Nam Ngum and Nam Theun The flow level falls again even with the right bank entry of the Mun Chi system from Thailand Although the Mun Chi basin drains 20 of the lower system average annual runoff is only 250 mm Runoff in the mainstream increases again with the entry from the left bank of the Se Kong from southern Laos and Se San and Sre Pok from Vietnam and Cambodia Floating market Cần Thơ Mekong delta Cầu khỉ monkey bridge and small nước mắm fish sauce workshop on the bank of the Tiền River branch of Mekong Binh Dai District Ben Tre Province Vietnam Hamlet Tiền River Binh Dai District Ben Tre Province Vietnam Table 2 Lower Mekong Mainstream annual flow 1960 to 2004 at selected sites 14 Mainstream site Catchment area km2 Mean annual flow as total MekongDischarge m3 s Volume km3 Runoff mm Chiang Saen 189 000 2 700 85 450 19Luang Prabang 268 000 3 900 123 460 27Chiang Khan 292 000 4 200 133 460 29Vientiane 299 000 4 400 139 460 30Nong Khai 302 000 4 500 142 470 31Nakhon Phanom 373 000 7 100 224 600 49Mukdahan 391 000 7 600 240 610 52Pakse 545 000 9 700 306 560 67Stung Treng 635 000 13 100 413 650 90Kratie 646 000 13 200 416 640 91Basin Total 760 000 14 500 457 600 100Flows at Chiang Saen entering the lower basin from Yunnan make up about 15 of the wet season flow at Kratie This rises to 40 during the dry season even this far downstream During the wet season the proportion of average flow coming from Yunnan rapidly decreases downstream of Chiang Saen from 70 to less than 20 at Kratie The dry season contribution from Yunnan is much more significant The major portion of the balance comes from Laos which points to a major distinction in the low flow hydrology of the river One fraction comes from melting snow in China and Tibet and the rest from over season catchment storage in the lower basin This has implications for the occurrence of drought conditions For example if runoff from melting snow in any given year is very low then flows upstream of Vientiane Nong Khai would be lower 14 In a large river system like the Mekong seasonal flows can be quite variable from year to year Although the pattern of the annual hydrograph is fairly predictable its magnitude is not The average monthly flows along the mainstream are listed in Table 3 providing an indication of their range and variability from year to year At Pakse for example flood season flows during August would exceed 20 000 cubic metres per second nine years out of ten but exceed 34 000 m3 s only one year in ten 14 Table 3 Mekong Mainstream monthly discharge 1960 2004 m3 s 14 Month Chiang Saen Luang Prabang Vientiane Nakhon Phanom Mukdahan Pakse KratieJan 1 150 1 690 1 760 2 380 2 370 2 800 3 620Feb 930 1 280 1 370 1 860 1 880 2 170 2 730Mar 830 1 060 1 170 1 560 1 600 1 840 2 290Apr 910 1 110 1 190 1 530 1 560 1 800 2 220May 1 300 1 570 1 720 2 410 2 430 2 920 3 640Jun 2 460 3 110 3 410 6 610 7 090 8 810 11 200Jul 4 720 6 400 6 920 12 800 13 600 16 600 22 200Aug 6 480 9 920 11 000 19 100 20 600 26 200 35 500Sep 5 510 8 990 10 800 18 500 19 800 26 300 36 700Oct 3 840 5 750 6 800 10 200 10 900 15 400 22 000Nov 2 510 3 790 4 230 5 410 5 710 7 780 10 900Dec 1 590 2 400 2 560 3 340 3 410 4 190 5 710There is little evidence from the last 45 years of data of any systematic changes in the hydrological regime of the Mekong 14 Geology EditThe internal drainage patterns of the Mekong are unusual when compared to those of other large rivers 2 Most large river systems that drain the interiors of continents such as the Amazon Congo and Mississippi have relatively simple dendritic tributary networks that resemble a branching tree 19 Typically such patterns develop in basins with gentle slopes where the underlying geological structure is fairly homogeneous and stable exerting little or no control on river morphology 20 In marked contrast the tributary networks of the Salween Yangtze and particularly the Mekong are complex with different sub basins often exhibiting different and distinct drainage patterns These complex drainage systems have developed in a setting where the underlying geological structure is heterogeneous and active and is the major factor controlling the course of rivers and the landscapes they carve out 21 The elevation of the Tibetan Plateau during the Tertiary period was an important factor in the genesis of the south west monsoon 22 which is the dominant climatic control influencing the hydrology of the Mekong Basin Understanding the nature and timing of the elevation of Tibet and the Central Highlands of Vietnam therefore helps explain the provenance of sediment reaching the delta and the Tonle Sap Great Lake today Studies of the provenance of sediments in the Mekong delta reveal a major switch in the source of sediments about eight million years ago Ma 23 24 From 36 to 8 Ma the bulk 76 of the sediments deposited in the delta came from erosion of the bedrock in the Three Rivers Area From 8 Ma to the present however the contribution from the Three Rivers Area fell to 40 while that from the Central Highlands rose from 11 to 51 One of the most striking conclusions of provenance studies is the small contribution of sediment from the other parts of the Mekong basin notably the Khorat Plateau the uplands of northern Laos and northern Thailand and the mountain ranges south of the Three Rivers area The last glacial period came to an abrupt end about 19 000 years ago 19 ka when sea levels rose rapidly reaching a maximum of about 4 5 m above present levels in the early Holocene about 8 ka 25 At this time the shoreline of the South China Sea almost reached Phnom Penh and cores recovered from near Angkor Borei contained sediments deposited under the influence of tides and salt marsh and mangrove swamp deposits 25 Sediments deposited in the Tonle Sap Great Lake about this time 7 9 7 3 ka also show indications of marine influence suggesting a connection to the South China Sea 26 Although the hydraulic relationships between the Mekong and the Tonle Sap Great Lake systems during the Holocene are not well understood it is clear that between 9 000 and 7 500 years ago the confluence of the Tonle Sap and the Mekong was in proximity to the South China Sea The present river morphology of the Mekong Delta developed over the last 6 000 years 2 During this period the delta advanced 200 km over the continental shelf of the South China Sea covering an area of more than 62 500 km2 From 5 3 to 3 5 ka the delta advanced across a broad embayment formed between higher ground near the Cambodian border and uplands north of Ho Chi Minh City During this phase of its development the delta was sheltered from the wave action of long shore currents and was constructed largely through fluvial and tidal processes 27 At this time the delta was advancing at a rate of 17 18 m per year After 3 5 ka however the delta had built out beyond the embayment and became subject to wave action and marine currents These deflected deposition south eastwards in the direction of the Ca Mau Peninsula which is one of the most recent features of the delta For much of its length the Mekong flows through bedrock channels i e channels that are confined or constrained by bedrock or old alluvium in the bed and riverbanks 2 Geomorphologic features normally associated with the alluvial stretches of mature rivers such as meanders oxbow lakes cut offs and extensive floodplains are restricted to a short stretch of the mainstream around Vientiane and downstream of Kratie where the river develops alluvial channels that are free of control exerted by the underlying bedrock The Mekong basin is not normally considered a seismically active area as much of the basin is underlain by the relatively stable continental block Nonetheless the parts of the basin in northern Laos northern Thailand Myanmar and China do experience frequent earthquakes and tremors The magnitude of these earthquakes rarely exceeds 6 5 on the Richter magnitude scale and is unlikely to cause material damage 28 page needed History Edit 19th century map showing the Mekong river as the Mei Kong river 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 210 BCE with Ban Chiang being an excellent example of 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 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 front line between the emergent states of Siam and Tonkin North Vietnam with Laos and Cambodia then 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 Spanish 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 invaded the region in the mid 19th century capturing Saigon in 1861 and establishing a protectorate over Cambodia in 1863 Members of the Mekong expedition of 1866 1868 The first systematic European exploration began with the French Mekong Expedition led by Ernest Doudard de Lagree and Francis Garnier which ascended the river from its mouth to Yunnan between 1866 and 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 found 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 expelled French from its former colony and defeated US supported governments During the wars in Indochina in the 1970s a significant quantity of explosives sometimes entire barges loaded with military ordnance sank in the Cambodian section of the Mekong as well as in the country s other waterways Besides being a danger for fishermen unexploded ordnance also creates problems for bridge and irrigation systems construction As of 2013 Cambodian volunteers are being trained with the support of the Office of Weapons Removal and Abatement within the US State Department Bureau of Political Military Affairs to conduct underwater explosive removal 29 The many maps of the river basin produced throughout recorded history reflect the region s changing human geography and politics 30 In 1995 Laos Thailand Cambodia and Vietnam established the Mekong River Commission MRC to manage and coordinate the use and care of the Mekong In 1996 China and Myanmar became dialogue partners of the MRC and the six countries now work together in a cooperative framework In 2000 the governments of China Laos Thailand and Myanmar signed a Agreement on Commercial Navigation on Lancang Mekong River among the Governments of the People s Republic of China the Lao People s Democratic Republic the Union of Myanmar and the Kingdom of Thailand which is the mechanism for cooperation with regard to riverine trade on the upper stretches of the Mekong 31 32 Natural history Edit Extirpated from most of its pan Asian range Cantor s giant softshell turtle can still be found along a stretch of the Mekong in Cambodia Khmer called Kanteay The Mekong basin is one of the richest areas of biodiversity in the world Only the Amazon boasts a higher level of bio diversity 2 Biota estimates for the Greater Mekong Subregion GMS include 20 000 plant species 430 mammals 1 200 birds 800 reptiles and amphibians 33 and an estimated 850 freshwater fish species excluding euryhaline species mainly found in salt or brackish water as well as introduced species 34 The most species rich orders among the freshwater fish in the river basin are cypriniforms 377 species and catfish 92 species 35 New species are regularly described from the Mekong In 2009 145 species previously unknown to science were described from the region including 29 fish species two bird species 10 reptiles five mammals 96 plants and six amphibians 36 Between 1997 and 2015 an average of two new species per week were discovered in the region 37 The Mekong Region contains 16 WWF Global 200 ecoregions the greatest concentration of ecoregions in mainland Asia 2 No other river is home to so many species of very large fish 38 The biggest include three species of Probarbus barbs which can grow up to 1 5 m 5 ft and weigh 70 kg 150 lb 39 the giant freshwater stingray Himantura polylepis syn H chaophraya which can reach at least 5 m 16 ft in length and 1 9 m 6 ft 3 in in width 40 the giant pangasius Pangasius sanitwongsei giant barb Catlocarpio siamensis and the endemic Mekong giant catfish Pangasianodon gigas The last three can grow up to about 3 m 10 ft in length and weigh 300 kg 660 lb 38 All of these have declined drastically because of dams flood control and overfishing 38 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 with only 85 individuals remaining 41 Among other wetland mammals that have been living in and around the river are the smooth coated otter Lutra perspicillata and fishing cat Prionailurus viverrinus The endangered Siamese crocodile Crocodylus siamensis occurs in small isolated pockets within the northern Cambodian and Laotian portions of the Mekong River The saltwater crocodile Crocodylus porosus once ranged from the Mekong Delta up the river into Tonle Sap and beyond but is now extinct in the river along with being extinct in all of Vietnam and possibly even Cambodia Protected areas Edit The headwaters of the Mekong in Zadoi County Qinghai China are protected in Sanjiangyuan National Nature Reserve The name Sanjiangyuan means the sources of the Three Rivers The reserve also includes the headwaters of the Yellow River and the Yangtze The section of the river flowing through deep gorges in Yunnan Province is part of the Three Parallel Rivers of Yunnan Protected Areas a UNESCO World Heritage Site The Tonle Sap Biosphere Reserve in Cambodia contains the largest lake in Southeast Asia It is a UNESCO Biosphere reserve Bank erosion on the Song Tien a Mekong branch Binh Dai District Ben Tre Province Vietnam Natural phenomena Edit The low tide level of the river in Cambodia is lower than the high tide level out at sea and the flow of the Mekong inverts with the tides throughout its stretch in Vietnam and up to Phnom Penh The very flat Mekong delta area in Vietnam is thus prone to flooding especially in the provinces of An Giang and Dong Thap Đồng Thap near the Cambodian border Fisheries Edit Fish Farming on Mekong branch Song Tien Đồng Thap Province Vietnam Aquatic biodiversity in the Mekong River system is the second highest in the world after the Amazon 42 43 The Mekong boasts the most concentrated biodiversity per hectare of any river 44 The largest recorded freshwater fish a 300 kg giant freshwater stingray in 2022 and previously a 293 kg Mekong giant catfish in 2005 were both caught in the Mekong River 45 The commercially valuable fish species in the Mekong are generally divided between black fish which inhabit low oxygen slow moving shallow waters and white fish which inhabit well oxygenated fast moving deeper waters 46 People living within the Mekong River system generate many other sources of food and income from what are often termed other aquatic animals OAAs such as freshwater crabs shrimp snakes turtles and frogs OAAs account for about 20 of the total Mekong catch 2 When fisheries are discussed catches are typically divided between the wild capture fishery i e fish and other aquatic animals caught in their natural habitat and aquaculture fish reared under controlled conditions Wild capture fisheries play the most important role in supporting livelihoods Wild capture fisheries are largely open access fisheries which poor rural people can access for food and income Broadly there are three types of fish habitats in the Mekong i the river including all the main tributaries rivers in the major flood zone and the Tonle Sap which altogether yield about 30 of wild catch landings ii rain fed wetlands outside the river floodplain zone including mainly rice paddies in formerly forested areas and usually inundated to about 50 cm yielding about 66 of wild catch landings and iii large water bodies outside the flood zone including canals and reservoirs yielding about 4 of wild catch landings 2 The Mekong Basin has one of the world s largest and most productive inland fisheries 42 47 48 49 An estimated two million tonnes of fish are landed a year in addition to almost 500 000 tonnes of other aquatic animals 50 Aquaculture yields about two million tonnes of fish a year 46 Hence the lower Mekong basin yields about 4 5 million tonnes of fish and aquatic products annually The total economic value of the fishery is between US 3 9 and US 7 billion a year 2 Wild capture fisheries alone have been valued at US 2 billion a year 48 This value increases considerably when the multiplier effect is included but estimates vary widely An estimated 2 56 million tonnes of inland fish and other aquatic animals are consumed in the lower Mekong every year 46 Aquatic resources make up between 47 and 80 of animal protein in rural diets for people who live in the Lower Mekong Basin 48 51 52 Fish are the cheapest source of animal protein in the region and any decline in the fishery is likely to significantly impact nutrition especially among the poor 42 51 53 54 Fish are the staple of the diet in Laos and Cambodia with around 80 of the Cambodian population s annual protein intake coming from fish caught in the Mekong River system with no alternative source to replace it An MRC report claims that dam projects on the Mekong River will reduce aquatic life by 40 by 2020 and predicted that 80 of fish will be depleted by 2040 Thailand will be impacted as its fish stocks in the Mekong will decline by 55 Laos will be reduced by 50 Cambodia by 35 and Vietnam by 30 55 It is estimated that 40 million rural people more than two thirds of the rural population in the lower Mekong basin are engaged in the wild capture fishery 2 Fisheries contribute significantly to a diversified livelihood strategy for many people particularly the poor who are highly dependent on the river and its resources for their livelihoods 47 48 52 They provide a principal form of income for numerous people and act as a safety net and coping strategy in times of poor agricultural harvests or other difficulties 47 48 52 In Laos alone 71 of rural households 2 9 million people rely on fisheries for either subsistence or additional cash income Around the Tonle Sap Lake in Cambodia more than 1 2 million people live in fishing communes and depend almost entirely on fishing for their livelihoods 2 Dams EditMain article Hydropower in the Mekong River Basin The Mekong is already heavily dammed with many more dams planned and under construction mostly for generating hydropower China built ten 56 or eleven 57 cascade dams on the Mekong mainstream between 1995 and mid 2019 leaving Vietnam Laos Cambodia and Thailand without same amount of water as before investment 58 China Laos and Cambodia are planning and or building more The Mekong has the fastest growing hydropower construction of any large river basin worldwide 59 The Lao Government is aiming to lift the nation out of poverty by making it the battery of Asia 60 Critics fear that China s ability to control the Mekong s flow gives it leverage over downstream nations who rely on China s goodwill In a worst case scenario China could well make demands on thirsty downstream countries who would not be able to refuse China could in short use its dams to weaponize water 57 The Jinghong Dam as of January 2020 update the nearest Chinese dam upstream of the Thai border has caused huge fluctuations in river levels affecting people s livelihoods downstream by disrupting the river s natural cycle It is impacting the ecosystem disturbing the migratory patterns of fish as well as riverbank plants and local agriculture downstream 60 Navigation Edit Mekong ferry Neak Loeung Cambodia Slow cruise boats Pakbeng Laos For thousands of years the Mekong River has been an important conduit for people and goods between the many towns on its banks Traditional forms of trade in small boats linking communities continue today however the river is also becoming an important link in international trade routes connecting the six Mekong countries to each other and also to the rest of the world 2 The Mekong is still a wild river and navigation conditions vary greatly along its length Broadly navigation of the river is divided between upper and lower Mekong with the upper part of the river defined as the stretch north of the Khone Falls in southern Laos and the lower part as the stretch below these falls Narrower and more turbulent sections of water in the upstream parts of the Mekong River coupled with large annual water level variations continue to present a challenge to navigation The seasonal variations in water level directly affect trade in this section of the river Volumes of trade being shipped decrease by more than 50 primarily due to the reduced draughts available during the low water season June January 2 Despite these difficulties the Mekong River is already an important link in the transit chain between Kunming and Bangkok with about 300 000 tonnes of goods shipped via this route each year 2 The volume of this trade is expected to increase by 8 11 per year Port infrastructure is being expanded to accommodate the expected growth in traffic with new facilities planned for Chiang Saen port 2 In Laos 50 and 100 DWT vessels are operated for regional trade Cargos carried are timber agricultural products and construction materials 2 Thailand imports a wide variety of products from China including vegetables fruit agricultural products and fertilisers The main exports from Thailand are dried longan fish oil rubber products and consumables Nearly all the ships carrying cargo to and from Chiang Saen Port are 300 DWT Chinese flag vessels 2 Waterborne trade in the lower Mekong countries of Vietnam and Cambodia has grown significantly with trends in container traffic at Phnom Penh port and general cargo through Can Tho port both showing steady increases until 2009 when a decrease in cargo volumes can be attributed to the global financial crisis and a subsequent decline in demand for the export of garments to the US 2 In 2009 Mekong trade received a significant boost with the opening of a new deep water port at Cai Mep in Vietnam This new port has generated a renewed focus on the Mekong River as a trade route The Cai Mep container terminals can accommodate vessels with a draught of 15 2 m equivalent to the largest container ships in the world These mother vessels sail directly to Europe or the United States which means that goods can be shipped internationally to and from Phnom Penh with only a single transshipment at Cai Mep 2 As an international river a number of agreements exist between the countries that share the Mekong to enable trade and passage between them The most important of these which address the full length of the river are 2 Agreement between China and Lao PDR on Freight and Passenger Transport along the Lancang Mekong River adopted in November 1994 Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin Article 9 Freedom of Navigation 5 April 1995 Chiang Rai Hanoi Agreement between Cambodia and Viet Nam on Waterway Transportation 13 December 1998 Agreement between and among the Governments of the Laos Thailand and Vietnam for Facilitation of Cross border Transport of Goods and People amended at Yangon Myanmar signed in Vientiane 26 November 1999 Agreement on Commercial Navigation on Lancang Mekong River among the governments of China Laos Myanmar and Thailand adopted at Tachileik 20 April 2000 Phnom Penh Agreement between Cambodia and Vietnam on the Transit of Goods 7 September 2000 New Agreement on Waterway Transportation between Vietnam and Cambodia signed in Phnom Penh 17 December 2009 In December 2016 the Thai cabinet of Prime Minister Prayut Chan o cha agreed in principle to a plan to dredge stretches of the Mekong and demolish rocky outcrops that are hindrances to easy navigation The international Lancang Mekong River navigation improvement plan for 2015 2025 conceived by China Myanmar Lao and Thailand aims to make the river more navigable for 500 tonne cargo vessels sailing the river from Yunnan to Luang Prabang a distance of 890 kilometres 61 China has been the driving force behind the demolition plan as it aims to expand trade in the area 62 The plan is split into two phases The first phase from 2015 to 2020 involves a survey a design and an assessment of the environmental and social impacts of the project These have to be approved by the four countries involved China Laos Myanmar Thailand The second phase 2020 2025 involves navigational improvements from Simao in China to 243 border posts in China and Myanmar a distance of 259 km 61 Local groups have countered that native inhabitants already operate their boats year round and that the plan to blast the rapids is not about making life better for local people but about enabling year round traffic of large Chinese commercial boats 63 On 4 February 2020 the Thai Cabinet voted to stop the project to blast and dredge 97 km of the river bed after Beijing failed to stump up the money for further surveys of the affected area 64 Bridges EditSee also List of crossings of the Mekong River Kizuna Bridge cross Mekong at Kampong Cham Construction of Myanmar Laos Friendship Bridge started on 19 February 2013 The bridge will be 691 6 m 2 269 ft long and have an 8 5 m 28 ft wide two lane motorway 65 The Thai Lao Friendship Bridge Thai saphanmitrphaph ithy law RTGS Saphan Mittraphap Thai Lao connects Nong Khai city with Vientiane in Laos The 1 170 m long 3 840 ft bridge opened on 8 April 1994 It has two 3 5 m wide 11 ft lanes with a single railway line in the middle On 20 March 2004 the Thai and Lao governments agreed to extend the railway to Tha Nalaeng in Laos This extension has since been completed The Second Thai Lao Friendship Bridge connects Mukdahan to Savannakhet The two lane 12 m wide 39 ft 1 600 m long 5 200 ft bridge opened to the public on 9 January 2007 The Third Thai Lao Friendship Bridge opened for traffic on 11 November 2011 connecting Nakhon Phanom Province Thailand and Thakhek Laos as part of Asian Highway 3 The Chinese and Thai governments agreed to build the bridge and share the estimated US 33 million cost The Fourth Thai Lao Friendship Bridge opened to traffic on 11 December 2013 66 It links Chiang Rai Province Thailand with Ban Houayxay Laos There is one bridge over the Mekong entirely within Laos Unlike the Friendship Bridges it is not a border crossing It is at Pakse in Champasak Province It is 1 380 m 4 528 ft long and was completed in 2000 15 6 19 95 N 105 48 49 51 E 15 1055417 N 105 8137528 E 15 1055417 105 8137528 Pakxe The Kizuna Bridge is in Cambodia in the city of Kampong Cham on the road linking Phnom Penh with the remote provinces of Ratanakiri and Mondolkiri and Laos The bridge opened for traffic on 11 December 2001 The Prek Tamak Bridge 40 km 25 mi north of Phnom Penh opened in 2010 Phnom Penh itself has no bridge under construction yet although two new bridges have recently opened on the Tonle Sap and the main bridge on the highway to Ho Chi Minh was duplicated in 2010 Another new bridge was built at Neak Leung on the Phnom Penh to Ho Chi Minh Highway 1 with Japanese government assistance and opened in 2015 In Vietnam since the year 2000 Mỹ Thuận Bridge crosses the first channel the left main branch of the Mekong the Song Tiền or Tiền Giang near Vĩnh Long and since 2008 Rạch Miễu Bridge crosses it near Mỹ Tho between the provinces of Tiền Giang and Bến Tre Cần Thơ Bridge crosses the second channel the right main distributary of the Mekong the Bassac Song Hau Inaugurated in 2010 it is the longest main span cable stayed bridge in Southeast Asia Environmental issues EditDrought linked to a changing climate and dozens of hydroelectric dams are damaging the Mekong ecosystem 67 68 69 When drought ends and the inevitable floods begin the effects of Mekong dams on flood pulse dynamics over the entire Lower Mekong are poorly understood 70 Sewage treatment is rudimentary in towns and urban areas throughout much of the Mekong s length such as Vientiane in Laos Water pollution impacts the river s ecological integrity as a result citation needed Much of the 8 3 billion tonnes of plastic present on earth 71 makes its way to the oceans Ninety percent of plastic in the oceans is flushed there by just 10 rivers The Mekong is one of them 72 A growing number of academics NGOs and scientists have urged the international community and the Mekong River Commission to reduce the use of hydropower giving concerns of long term sustainability Some of them have urged an immediate moratorium on new construction of hydropower projects and a shift to solar and other forms of renewable energy which are becoming more competitive and faster to install 73 See also Edit Rivers portalGreater Mekong Subregion Greater Mekong Sub region Academic and Research Network GMS Environment Operations Center Indochina Sekong River Mekong River Basin Hydropower Mekong River massacre 2011 killings on Mekong river Stung Sen River Mekong Expedition of 1866 1868 Fair river sharingReferences Edit a b S Liu P Lu D Liu P Jin W Wang 2009 Pinpointing source and measuring the lengths of the principal rivers of the world International Journal of Digital Earth 2 1 80 87 Bibcode 2009IJDE 2 80L doi 10 1080 17538940902746082 S2CID 27548511 a b c d e f g h i j k l m n o p q r s t u State of the Basin Report 2010 PDF Mekong River Commission Vientiane 2010 Sasipornkarn Emmy 16 August 2019 A dam building race threatens the Mekong River Deutsche Welle Retrieved 18 August 2019 Sripiachai Pattanapong 29 October 2019 Mekong River falls to critical level sand dunes emerge Bangkok Post Retrieved 26 November 2019 Beech Hannah 13 April 2020 China Limited the Mekong s Flow Other Countries Suffered a Drought The New York Times ISSN 0362 4331 Retrieved 14 April 2020 Nguyen Thi Dieu 1999 The Mekong River and the Struggle for Indochina Water War and Peace Westport Praeger p 36 ISBN 9780275961374 Baxter Sagart Reid H 1857 A System of Modern Geography with Exercises of examination To which are added treatises on Astronomy and Physical Geography United Kingdom n p Universal Gazetteer of the World A Dictionary Geographical Historical and Statistical of the Various Kingdoms States Provinces Cities Towns Forts Harbors Rivers Lakes Seas Mountains amp c in the World Also the Census of 1850 1852 United States Z amp B F Pratt A Gazetteer of the World Brazil Derry 1856 United Kingdom A Fullarton Roberts G 1834 The Elements of Modern Geography and General History on a Plan Entirely New New Edition Improved Etc United Kingdom n p Hamilton W 1815 The East India Gazetteer Containing Particular Descriptions of the Empires Kingdoms Principalities Provinces Cities Towns Districts Fortresses Harbours Rivers Lakes amp c of Hindostan and the Adjacent Countries India Beyond the Ganges and the Eastern Archipelago Together with Sketches of the Manners Customs Institutions Agriculture Commerce Manufactures Revenues Population Castes Religion History amp c of Their Various Inhabitants United Kingdom J Murray Wangkiat Paritta 15 January 2017 Against the flow Bangkok Post No Spectrum Retrieved 3 May 2018 a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab Mekong River Commission 2005 Overview of the Hydrology of the Mekong Basin PDF MRC Vientiane Laos Archived from the original PDF on 13 July 2018 Retrieved 21 April 2012 G Lacombe A Pierret C T Hoanh O Sengtaheuanghoung A Noble 2010 Conflict migration and land cover changes in Indochina a hydrological assessment Ecohydrology 3 4 382 391 doi 10 1002 eco 166 S2CID 131563940 Michael Buckley 30 March 2015 The Price of Damming Tibet s Rivers The New York Times p A25 Archived from the original on 31 March 2015 Retrieved 1 April 2015 Other plans call for diversion of water from the Brahmaputra Salween and Mekong all rivers that cross national boundaries Yeophantong Pichamon 2014 China s Lancang Dam Cascade and Transnational Activism in the Mekong Region Who s Got the Power Asian Survey 54 4 700 724 doi 10 1525 as 2014 54 4 700 Mekong River in Golden Triangle drops to lowest level in a century Thai PBS 20 July 2019 Retrieved 21 July 2019 M Clark L Schoenbohm L Royden K Whipple B Burchfiel W Zhang W Tang E Wang L Chen 2004 Surface uplift tectonics and erosion of eastern Tibet from large scale drainage patterns Tectonics 23 TC1006 227 234 Bibcode 2004Tecto 23 1006C doi 10 1029 2002TC001402 C Twidale 2004 River patterns and their meanings Earth Science Reviews 67 3 4 159 218 Bibcode 2004ESRv 67 159T doi 10 1016 j earscirev 2004 03 001 S K Tandon amp R Sinha 2007 Geology of large river systems In A Gupta ed Large rivers geomorphology and management London John Wiley amp Sons pp 7 28 ISBN 978 0 470 84987 3 P D Clift amp A R Plumb 2008 The Asian monsoon causes history and effects Cambridge UK Cambridge University Press ISBN 9780521847995 P D Clift A Carter I H Campbell M Pringle V Nguyen C Allen C M Allen K V Hodges T T Mai 2006 Thermochronology of mineral grains in the Red and Mekong Rivers Viet Nam Provenance and exhumation implications for Southeast Asia PDF Geochemistry Geophysics Geosystems 7 10 1 28 Bibcode 2006GGG 710005C doi 10 1029 2006GC001336 P D Clift G Layne amp J Blusztajn 2004 Marine sedimentary evidence for monsoon strengthening Tibetan uplift and drainage evolution in East Asia Geophysical Monograph Series 149 2004 255 282 Bibcode 2004GMS 149 255C doi 10 1029 149GM14 ISBN 0 87590 414 9 a b T Tamura Y Saito S Sotham B Bunnarin K Meng S Im S Choup F Akiba 2009 Initiation of the Mekong River Delta at 8 ka Evidence from the sedimentary succession in the Cambodian lowland Quaternary Science Reviews 28 3 4 327 344 Bibcode 2009QSRv 28 327T doi 10 1016 j quascirev 2008 10 010 D Penny 2006 The Holocene history and development of the Tonle Sap Cambodia Quaternary Science Reviews 25 3 4 310 322 Bibcode 2006QSRv 25 310P doi 10 1016 j quascirev 2005 03 012 T K Ta V L Nguyen M Tateishi I Kobayashi S Tanabe Y Saito 2002 Holocene delta evolution and sediment discharge of the Mekong River Southern Viet Nam Quaternary Science Reviews 21 16 17 1807 1819 Bibcode 2002QSRv 21 1807T doi 10 1016 S0277 3791 02 00007 0 C H Fenton P Charusiri amp S H Wood 2003 Recent paleoseismic investigations in northern and western Thailand Annals of Geophysics 46 5 957 981 hdl 2122 998 Cambodia Demining in the depths Archived 25 March 2013 at the Wayback Machine Denise Hruby 24 March 2013 Romanos Christoforos 2023 Liquid Territories configurations of geographic space in the cartographic projections of the Mekong River s catchment areas Delft Delft University of Technology p 325 Lazarus K Dubeau P Bambaradeniya C Friend R Sylavong L 2006 Increasing pace of change PDF An Uncertain Future Biodiversity and Livelihoods Along the Mekong River in Northern Lao PDR Bangkok Thailand and Gland Switzerland The World Conservation Union IUCN pp 21 24 ISBN 978 2 8317 0956 7 Retrieved 21 August 2019 Agreement on Commercial Navigation on Lancang Mekong River among the Governments of the People s Republic of China the Lao People s Democratic Republic the Union of Myanmar and the Kingdom of Thailand PDF JCCN 20 April 2000 Archived from the original PDF on 21 August 2019 Retrieved 21 August 2019 C Thompson 2008 First Contact in the Greater Mekong PDF WWF Greater Mekong Program permanent dead link K G Hortle 2009 Fishes of the Mekong how many species are there Catch and Culture Mekong River Commission Archived from the original on 30 July 2012 Valbo Jorgensen J Coates D and Hortle K 2009 Fish diversity in the Mekong River basin pp 161 196 in Campbell I C editor The Mekong Biophysical Environment of an International River Basin 1st edition Academic Press Elsevier ISBN 978 0 12 374026 7 N Gephart G Blate C McQuistan C Thompson 2010 New Blood Greater Mekong New Species Discoveries 2009 PDF WWF 163 new species including Klingon Newt discovered Fox News 20 December 2016 Retrieved 20 December 2016 a b c River of Giants Giant Fish of the Mekong PDF WWF Greater Mekong Program 2012 Froese Rainer and Pauly Daniel eds 2017 Species of Probarbus in FishBase February 2017 version Last P R Compagno L J V 1999 Myliobatiformes Dasyatidae In Carpenter K E Niem V H eds FAO identification guide for fishery purposes The living marine resources of the Western Central Pacific Food and Agriculture Organization of the United Nations pp 1479 1505 ISBN 92 5 104302 7 Ryan Gerard Edward Dove Verne Trujillo Fernando Doherty Paul F 2011 Irrawaddy dolphin demography in the Mekong River an application of mark resight models Ecosphere 2 5 art58 doi 10 1890 ES10 00171 1 a b c International Center for Environmental Management 2010 Strategic Environmental Assessment SEA of hydropower on the Mekong mainstream PDF Mekong River Commission J W Ferguson M Healey P Dugan C Barlow 2011 Potential Effects of Dams on Migratory Fish in the Mekong River Lessons from the Fraser and Columbia Rivers Environmental Management 47 1 141 159 Bibcode 2011EnMan 47 141F doi 10 1007 s00267 010 9563 6 PMID 20924582 S2CID 19900859 J Valbo Jorgensen D Coates amp K G Hortle 2009 Fish diversity in the Mekong River Basin In I C Campbell ed The Mekong Biophysical Environment of an International River Basin London Elsevier Publishers pp 161 196 ISBN 978 0123740267 Largest freshwater fish ever recorded caught in Cambodia the Guardian Associated Press 20 June 2022 Retrieved 20 June 2022 a b c Mekong River Commission 2010 Assessment of Basin wide Development Scenarios Technical Note 11 Impacts on Fisheries PDF Mekong River Commission permanent dead link a b c E Baran amp C Myschowoda 2009 Dams and fisheries in the Mekong Basin Aquatic Ecosystem Health and Management 12 3 227 234 doi 10 1080 14634980903149902 S2CID 85279301 a b c d e E Baran amp B Ratner 2007 The Don Sahong Dam and Mekong Fisheries PDF Science Brief World Fish Center Archived from the original PDF on 9 May 2013 Retrieved 12 October 2012 J Sarkkula M Keskinen J Koponen M Kummu J E Richery amp O Varis 2009 Hydropower in the Mekong Region What Are the Likely Impacts Upon Fisheries In F Molle T Foran M Kakonen eds Contested Waterscapes in the Mekong Region Hydropower Livelihoods and Governance London Earthscan pp 227 249 ISBN 978 1 84407 707 6 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link K G Hortle 2007 Consumption and the yield of fish and other aquatic animals from the Lower Mekong Basin PDF MRC Technical Paper No 16 Mekong River Commission a b S Bush 2007 Give a man a fish Contextualising Living Aquatic Resources Development in the Lower Mekong Basin PDF AMRC Working Papers 8 Australian Mekong Resource Centre University of Sydney a b c R Friend amp D J H Blake 2009 Negotiating trade offs in water resources development in the Mekong Basin implications for fisheries and fishery based livelihoods Water Policy 11 S1 13 30 doi 10 2166 wp 2009 001 I G Baird 2009 The Don Sahong Dam Potential Impacts on Regional Fish Migrations Livelihoods and Human Health PDF POLIS Project on Environmental Governance University of Victoria permanent dead link I G Baird 2011 The Don Sahong Dam Critical Asian Studies 43 2 211 235 doi 10 1080 14672715 2011 570567 S2CID 55168234 Wipatayotin Apinya 20 July 2019 Dam tests spark crisis Bangkok Post Retrieved 20 July 2019 Dam disaster on the way Opinion Bangkok Post 20 July 2019 Retrieved 20 July 2019 a b Chellaney Brahma 2 August 2019 Damming the Mekong Basin to Environmental Hell Opinion Project Syndicate Retrieved 5 August 2019 China s dams exacerbated extreme drought in lower Mekong Study Al Jazeera 25 April 2020 Requiem for a river The Economist Retrieved 18 February 2016 a b Bainbridge Amy Vimonsuk Supattra 20 January 2020 Chinese dams are exacerbating Mekong River drought and locals say they ve never seen it this low ABC News Australian Broadcasting Corporation Retrieved 20 January 2020 a b Suksamran Nauvarat 9 January 2017 Locals slam Mekong blasting plan Bangkok Post Retrieved 9 January 2017 Spare the Mekong Opinion Bangkok Post 30 December 2016 Retrieved 30 December 2016 Roykaew Niwat 17 July 2019 China must be sincere on Mekong Opinion Bangkok Post Retrieved 20 July 2019 Thais ditch China led plan to dredge Mekong The Straits Times 6 February 2020 Retrieved 6 February 2020 Myanmar Laos start building Mekong River friendship bridge Xinhua English news cn Archived from the original on 25 February 2013 Retrieved 17 March 2013 vientianetimes org Archived from the original on 29 December 2012 Retrieved 17 March 2013 Sasipornkarn Emmy 16 August 2019 A dam building race threatens the Mekong River Deutsche Welle Retrieved 18 August 2019 Sripiachai Pattanapong 29 October 2019 Mekong River falls to critical level sand dunes emerge Bangkok Post Retrieved 26 November 2019 Beech Hannah 13 April 2020 China Limited the Mekong s Flow Other Countries Suffered a Drought The New York Times ISSN 0362 4331 Retrieved 14 April 2020 Pokhrel Yadu et al 10 December 2018 Potential Disruption of Flood Dynamics in the Lower Mekong River Basin Due to Upstream Flow Regulation Scientific Reports 8 17767 17767 Bibcode 2018NatSR 817767P doi 10 1038 s41598 018 35823 4 PMC 6288158 PMID 30532063 Franzen Harald 20 July 2017 There are 8 3 billion tons of plastic in the world Deutsche Welle Retrieved 17 April 2018 Franzen Harald 30 November 2017 Almost all plastic in the ocean comes from just 10 rivers Deutsche Welle Retrieved 17 April 2018 Fawthrop Tom 28 November 2019 Dams and Climate Change Kill the Mekong YaleGlobal Online Yale University Retrieved 26 November 2019 Further reading EditKuenzer C I Campbell M Roch P Leinenkugel V Q Tuan and S Dech 2012 Understanding the impact of hydropower developments in the context of upstream downstream relations in the Mekong river basin In Sustainability Science 8 4 pp 565 584 DOI 10 1007 s11625 012 0195 z Kuenzer C H Guo J Huth P Leinenkugel X Li and S Dech 2013 Flood Mapping and Flood Dynamics of the Mekong Delta ENVISAT ASAR WSM Based Time Series Analyses In Remote Sensing 5 pp 687 715 DOI 10 3390 rs5020687 Leinenkugel P C Kuenzer N Oppelt and S Dech 2013 Characterisation of land surface phenology and land cover based on moderate resolution satellite data in cloud prone areas A novel product for the Mekong Basin In Remote Sensing of Environment 136 pp 180 198 DOI 10 1016 j rse 2013 05 004 Moder F C Kuenzer Z Xu P Leinenkugel and Q Bui Van 2012 IWRM for the Mekong Basin In Renaud F G and C Kuenzer eds The Mekong Delta System Interdisciplinary Analyses of a River Delta Dordrecht Springer pp 133 166 Renaud F G und C Kuenzer 2012 The Mekong Delta System Interdisciplinary Analyses of a River Delta Springer Environmental Science and Engineering Dordrecht Springer ISBN 978 94 007 3961 1 Kuenzer C and F G Renaud 2012 Climate Change and Environmental Change in River Deltas Globally In Renaud F G and C Kuenzer eds The Mekong Delta System Interdisciplinary Analyses of a River Delta Dordrecht Springer pp 7 48 Kuenzer C 2014 Remote Sensing the Mekong In International Journal of Remote Sensing 35 8 pp 2747 2751 DOI 10 1080 01431161 2014 890377 Kuenzer C P Leinenkugel M Vollmuth and S Dech 2014 Comparing global land cover products implications for geoscience applications an investigation for the trans boundary Mekong Basin In International Journal of Remote Sensing 35 8 pp 2752 2779 DOI 10 1080 01431161 2014 890305 Shoemaker Bruce Robichaud William eds November 2019 Dead in the Water Global Lessons from the World Bank s Model Hydropower Project in Laos Paper ed Madison University of Wisconsin Press ISBN 9780299317942 Retrieved 26 November 2019 External links Edit Wikimedia Commons has media related to Mekong Map all coordinates using OpenStreetMap Download coordinates as KMLThe WISDOM Project a Water related Information System for the Mekong Delta Mekong River Commission CGIAR Research Program on Water Land and Ecosystems Greater Mekong Archived 9 July 2021 at the Wayback Machine Mekong Watch Countries of the Mekong River The Greater Mekong Subregion Asian Development Bank Rivers Network Mekong river blog Archived 5 November 2018 at the Wayback Machine Retrieved from https en wikipedia org w index php title Mekong amp oldid 1149491329, wikipedia, wiki, book, books, library,

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