Bridges

The Thai-Lao Friendship Bridge (Thai: สะพาน มิตรภาพ ไทย - ลาว Mittaphap Saphan Thailand and Laos) connects Nong Khai city of Vientiane in Laos. The 1170 feet (3840 m) long bridge has two 3.5 meter (11 ft) wide channel with a single rail line in the middle. On March 20, 2004, governments agreed Thailand and Laos to extend the railway to Tha Nalaeng Laos, this expansion has been completed.

The second Friendship Bridge connecting Thailand and Laos Savannakhet Mukdahan. The two lanes of 12 meters (39 feet) wide, 1,600 meters (5,200 feet) long bridge was opened in January 9, 2007.

There are only three bridges, located in Champasak province, Laos. Unlike bridges of friendship, the bridge is not a border. It is 1380 meters (4528 feet) long and was completed in 2000 (Pakxe bridge 15 ° 6'19 .95 "N 105 ° 48'49 .51" E).

A new bridge over the Mekong River and was completed in 2011, connecting the border towns of Chiang Khong (Thailand) and Ban Houayxay (Laos) as part of the Asian Highway third Chinese and Thai governments agreed to build bridges and share of the estimated costs 33USD million U.S. dollars project.

Another new bridge was built [Neak Leung], a Phnom Penh to Ho Chi Minh Japanese state support, expected to open in 2014.

Cambodia has one of two lanes of the bridge, the Kizuna bridge in the city of Kompong Cham, on the highway linking Phnom Penh with the remote provinces of Ratanakiri and Mondulkiri provinces, Laos and beyond.

The bridge Prek TAMAK, 40 km north of Phnom Penh will give another bond in 2011.

Phnom Penh itself has no bridge under construction, although two new bridges have been recently opened in the Tonle Sap, and the main road bridge in Ho Chi Minh doubled in 2010.

In Vietnam since 2000, the My Thuan Bridge (MY Thuan) exceeds the first channel first ten kilometers of Vinh Long (Vinh Long), Rach Mieu Bridge, and from 2008 (Rach Mieu) than it is about ten miles before de My Tho ( My Tho), between the provinces of de road Giang (Road Giang) and Ben Tre (Ben Tre).

Bridge Can Tho (Can Tho), through the second channel, which opened in 2010, is the longest cable-stayed bridge with a major in South Asia.

History

The difficulty of navigating the river means that a country divided, rather than States, people living near him. The first regulation known date 2100 BC, with Ban Chiang is an excellent example of this culture of the Iron Age. The first civilization was recorded on 1 Indianized century culture Khmer of Funan in the Mekong Delta. The excavation of Oc Eo, near modern An Giang, have found coins from as far away as the Roman Empire. This has been replaced by the state of Khmer culture Chenla to the fifth century. The Khmer empire of Angkor was the last great Indianized state in the region. At the time of the fall of the Khmer empire, the Mekong has been the front line between the states emerging from Siam and Tonkin (North Vietnam), Laos and Cambodia, then situated on the coast, torn between her influence.

First meeting in Europe was in the Mekong Portugal, Antonio de Faria in 1540, the European map of 1563 describes the river, although little is known of the river upstream of the delta. European interest only occasionally: the Spaniards and Portuguese mounted some missionary and trade expeditions, while the Dutch Gerrit van Wuysthoff led an expedition along the river to Vientiane in 1641-42.

The French have a serious interest in the region, half of 19 century, the capture of Saigon in 1861 and the creation of protected areas in Cambodia in 1863.

The systematic exploration began with the French expedition led by Ernest Mekong Doudard of Lagree and Francis Garnier, which ascended the river from its mouth to Yunnan between 1866 and 1868. Its main conclusion was that the Mekong had too many falls and rapids to be always useful for navigation. The source of the river is by Pyotr Kuzmich Kozlov in 1900.

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

After the Vietnam War, tensions between the pro-American government of Thailand and the new communist governments in other countries prevented cooperation on use of river.

Geology Of The Mekong River Basin

Patterns of internal drainage of the Mekong is unusual compared to other major rivers, the most important river systems that drain the interior of continents, such as the Amazon, Congo and Mississippi, have relatively simple dendritic tributary system that looks to a tree branch. Typically, such patterns develop in basins with gentle slopes where the underlying geological structure is rather homogeneous and stable, to little or no control over the river morphology. In contrast, the network tributary of the Salween, Yangtze, Mekong and especially the complex with various sub-basins are often different, and different types of drainage. These drainage systems have evolved in a complex environment where the underlying geology is heterogeneous and active, and is the main factor controlling the rivers and the landscapes they cut.

Height of the Tibetan plateau during the Tertiary period was an important factor in the legislative history of the southwest monsoon, which is the dominant climate influence the control of the hydrology of the Mekong Basin. Understanding the nature and timing of the share of Tibet (and in the Central Highlands of Vietnam) in order to help explain the origin of sediments to the delta and Lake Tonle Sap Great today. He studied the origin of sediments in the Mekong Delta to disclose the source of sediments in large clutch of about eight million years ago (Ma). Mon 36-8 mass (76%) of sediments deposited in the delta became the erosion of the bedrock Three Rivers area. 8 mA at stake, however, Three Rivers Area decreased by 40%, while the Central Highlands increased by 11-51%.

One of the surprising findings of the research farms of origin is a small portion of sediment from other parts of the Mekong basin, particularly the Khorat Plateau, northern highlands of Laos and northern Thailand, and the mountains south of the area Three Rivers.

The last ice age ended abruptly around 19,000 years ago (KA) when water levels rose rapidly, reaching a maximum of about 4.5 m above the present level of the Early Holocene at about 8 ka. At this point the coast of the South China Sea has almost reached Phnom Penh and the cores recovered near Angkor Borei contained sediments deposited under the influence of tides and marsh deposits of salt marshes and mangroves. Sediments deposited in Lake Tonle Sap Great around this time (7.9 to 7.3 ka) also shows signs of marine influence, suggesting a link to the South China Sea. Although the hydraulic relationship between the Mekong and Tonle Sap lake systems during the Holocene is not well understood, it is clear that between 9000 and 7500 years, at the confluence of the Tonle Sap and Mekong was in the immediate vicinity the South China Sea.

The current morphology of the river in the Mekong Delta evolved over the last 6000 years. During this period, the Delta advanced 200 km on the continental shelf in the South China Sea, covering an area of ​​over 62 500 km2. From 5.3 to 3.5 ka Delta advanced wide embayment formed between the higher ground near the border with Cambodia and the northern highlands of Ho Chi Minh City. During the development phase of the Delta away from the waves and currents along the shore has been built largely on river and tidal processes. Currently, Delta proceeded at a speed of 17-18 meters per year. After 3.5 ka, however, the delta was built in the embayment, and they came to wave action and sea currents. They bend to the deposition of the south-east of the Ca Mau peninsula, which is one of the newest features of the delta.

For most of the duration of the flow in the canals of the Mekong rock, or channels, which are limited or restricted by rock or old bed of the river flood and beaches. Geomorphological characteristics normally associated with the flooding of sections of mature rivers, such as bends, oxbow lakes, cut-offs, as well as extensive flooding is limited to a short stretch of the mainstream around Vientiane and Kratie, where the river valley to develop flood control channels are available free of charge created by the underlying rock.

Mekong Basin are generally not considered an active seismic zone, as the basin is covered by the relatively stable block of the continent. However, some parts of the basin in northern Laos, northern Thailand, Myanmar and China are experiencing frequent earthquakes and tremors. The magnitude of these earthquakes rarely exceed 6.5 on the Richter scale and is unlikely to cause damage.

Natural History Of The Mekong Basin

Mekong Basin is one of the richest areas of biodiversity in the world. Only Amazon can boast of a higher degree of biodiversity. Estimates of the biota of the Greater Mekong (GMS) consists of 20 000 plant species, 430 mammals, birds 1200, 800 reptiles and amphibians and 850 species approximately. In 2009, 145 new species described in the Mekong region, including 29 species previously unknown to science, two new species of birds, ten reptiles, five mammals, 96 amphibians and six new plants Mekong region contains 16 WWF Global 200 ecoregions, the largest concentration of ecoregions in continental Asia.

No other river is home to many species of large fish. The largest is the giant river carp (Probarbus Jullien), which can grow up to 1.5 meters (4 feet 11) and weighs 70 kilograms (150 pounds), the Mekong freshwater stingray (Himantura Chaophraya), which can have a wingspan up to 4.3 meters (14 feet), the giant pangasius (Pangasius sanitwongsei), Siamese giant carp (Catlocarpio siamensis) and endemic to the Mekong giant catfish (Pangasianodon gigas), all three, that can grow up to 3 meters (9 feet 10) tall and weighs 300 pounds (660 lb). All these are in serious decline, both because of dams and flood protection and over-fishing.

A species of freshwater dolphin, Irrawaddy dolphin (Orcaella brevirostris), were once common throughout the lower Mekong, but it is now very rare.

Among the mammals wetlands others who lived in and around the river is short-haired otter (Lutra perspicillata) and fishing cat (Felis raccoon).

The Siamese crocodile endangered (Crocodylus siamensis) occur in small isolated pockets in northern Cambodia and Laos on the Mekong. The saltwater crocodile (Crocodylus porosus) once extended the Mekong Delta to the river in the Tonle Sap Lake and on, but it is now extinct in the river, while off to Vietnam and even Cambodia .

Environmental Concerns

The last two problems are the construction of the dam the river and jump the rapids.

Several dams have been built on tributaries of the river, especially the Pak Mun dam in Thailand. This has been criticized because of the costs and damage to the environment and living conditions of villagers affected, but none has been built on the main part himself.

China is committed to a comprehensive program for the construction of the dam the river itself: it is already in the first three are called Manwan dam, another twelve are under consideration.

Impoverished Cambodia is a nation that is totally dependent on the river for food and most of its booming economy. The annual floods provide plenty of water for the crops of the otherwise dusty dry earth, and to refresh Tonle Sap, but its cities are vulnerable to flooding. Tonle Sap Biosphere Reserve was created to try to protect areas surrounding the Tonle Sap lake and the river, which is associated with the Mekong River [8].

The Mekong River Commission, a group of countries in the region, has accused China of blatantly ignoring the UN downstream in its plans to dam the river in an effort to stop the dams, but without success. From China dam first, many species are endangered, including the Mekong dolphin and dugong, water levels fell ferries blocked, catches are small and the catch is less than half of the dam The pre-turnover in Chiang Rai port is less than a quarter of the previous years, and excerpts from Chiang Rai to Luang Prabang have lengthened isolated from 8 am to 2 days due to insufficient water levels.

Despite these problems, new dams planned impact significantly worse if done as planned. All downstream Nations and the environment will suffer from added pollution (due to the development and relatively lax regulation and enforcement in China compared to Thailand, the poisoning of the food supply and pesticide runoff heavy industry, and promoting algal blooms from organophosphates from agriculture, and water hyacinth attack), the problems blocking the river that the fish do not swim upstream spawn, and potentially devastating very low water flow.

Other environmental issues arising from the increased flow of water in some parts of China clears rocks and sandbars, blasts gorges, and water, it slows down the dams and flood sections, and transfers the indigenous peoples. Cambodia is by far the most, depending on the delicate balance of water flow scenarios for fear of mass starvation, and devastating floods, which destroyed the Angkor kingdom 700 years ago. Laos largest cities all hug the Mekong as the largest city in Vietnam is not, and economic center of Ho Chi Minh City, which would be more vulnerable to low flow and pollution.

Watershed

The point at which it rises in its mouth, most of the sharp drop occurs in the Mekong what is called "the Upper Mekong Basin" (see below), a stretch of about 2200 km (1367 miles). Here, you go down to 4500 meters (14,764 feet) meters before entering the lower basin where the borders of Thailand, Laos, Burma, China, and combines the Golden Triangle. Downstream of the Golden Triangle, but the river is 2600 km 2600 km (1616 miles), through Laos, Thailand and Cambodia, in front of the South China Sea through a complex delta in Vietnam.

In the province of Yunnan in China, the river and its tributaries are limited by narrow gorges. Tax systems in this part of the basin are small. Only 14 watersheds that exceed 1 000 km2 (0 sq mi). In southern Yunnan, in the prefectures of Simao and Xishuangbanna, changes in the river, the valley opens, the floodplain widens and the river widens and slower.

Laos is located almost entirely in the Lower Mekong Basin. The 'landscape climate and land use are important factors in the formation of the river hydrology. The mountainous landscape means that only 16% of the land is cultivated in the plain terrace or in mountainous areas, moving the crops. When you move in mountain areas for agriculture (slash and burn), improve the soil 10-20 years, but the vegetation does not. The transition to agriculture is common in the highlands of northern Laos, and 'was reported to constitute up to 27% of all the land under rice cultivation. As elsewhere in the pool of forest cover has been steadily reduced over the past three decades, through permanent agriculture, and agriculture. The cumulative effects of these activities of the river system has not been measured.

Loss of forest cover in Thai territory at the bottom was the highest in all countries of the Mekong decline over the past 60 years. At the Korat Plateau, which includes Mun and Chi-dependent systems have been reduced forest cover from 42% in 1961 to 13% in 1993. Although this part of northern Thailand has an annual rainfall of over 1,000 mm, a high evaporation rate means it is classified as a semi-arid region. Therefore, although the Chi and Mun basins draining 15% of the entire Mekong Basin, they contribute only 6% of mean annual flow. Sandy soil and saline soil types are most common, which makes most land suitable for irrigated rice. Despite low fertility, but agriculture is intensive. The glutinous rice, maize and cassava are the main crops. Drought is by far the greatest water hazards in the region.

In Cambodia, the wet rice the main crop, and grown in the floodplain of the Tonle Sap, Mekong and Bassac rivers. More than half of Cambodia is still covered with forests and mixed evergreen deciduous, but forest cover has decreased by 73% in 1973 to 63% in 1993. Here, the river landscape is flat. Small changes in water level to determine the direction of water movement, including the reversal of the high flow in and out of the Tonle Sap basin of the Mekong River.

Mekong Delta in Vietnam is an intensive agriculture and left little natural vegetation. The forest cover is less than 10%. In the central highlands of Vietnam, forest cover has been reduced by over 95% in 1950 to nearly 50% in the mid-1990s. Agricultural expansion and population pressure are the main causes of land use and landscape changes. Both droughts and floods are common hazards in the delta, which many people believe to be most sensitive to hydrological changes upstream.

The Mekong Basin is divided into two parts: the upper basin in Tibet and China, and the Lower Mekong downstream from Yunnan of China to South China Sea. The upper basin accounts for 24% of the total area and contributes 15-20% of the water that flows into the Mekong River. The basin is narrow and steep here. Soil erosion is a serious problem and 50% of the sediment in the river basin is high.

The major tax systems to develop in the lower basin. These systems can be separated into two groups: the tributaries that contribute to significant flows during the rainy season and its tributaries that drain areas of low relief of decreased rainfall. The first group are left bank tributaries draining the high rainfall areas of Laos. The second group are those of the right bank of the rivers, mainly Mun and Chi, which drain a large part of northern Thailand.

Course

The Mekong rises, "Three Rivers Area 'of the Tibetan plateau Sanjiangyuan nature reserve as the Yangtze River and Lancang rivers along the Salween. It flows south through Yunnan through the Three Rivers Area Hengduan Mountains. After leaving China, which flows south- east, forming the border of Burma and Laos, about 100 km (62 miles) south-west of turns to form a short edge with Laos, Thailand. The Mekong River flows east and south of Laos, about 400 km (250 miles ), and defines the Laos-Thailand border, and some 850 km (530 miles), when it flows east, turning south through the Mid South-East Asia, which manages the capital of Laos, Vientiane. Mun River, at the confluence of occurs just before crossing the Mekong in Cambodia, where you get Sap River, which flows through the capital Phnom Penh, Cambodia.

Mekong slows its entry in Vietnam, where it divides into nine channels of the Mekong delta, emptying into the South China Sea.

Names

In English, the river is called the "Mekong", derived from "Mae Nam Khong," an expression both from Thailand and Laos. In Lao-Thai names, all major rivers are considered "mother river" is indicated by the prefix "Mae" which means "mother" and "nam" for water. In the Mekong, which means Mae Nam Khong Khong, the Mother of Water. "Khong" comes from the Sanskrit "Ganga", which means that the Ganges. Many northern Thailand and Laos, local refers to it as "Khong River". This is the case with the Mae Nam Ping in Chiang Mai, known as "the Ping River." Tonle Sap in Cambodia is a similar example - ". Sap River" where the Tonle translates as "Great lake or river," which makes the Tonle Sap River an unnecessary repetition of what is actually

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

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

• Burmese: မဲခေါင်မြစ်, IPA: [mɛ́ɡàuɴ mjɪ̰ʔ]
• Chinese: Riverhead: 加果空桑贡玛曲, 扎那曲 and 扎曲 Zā Qū, upper reaches: 澜沧江, 瀾滄江 Láncāng Jiāng ("Turbulent River", "Láncāng" is also same to Lan Xang in Chinese), middle and lower reaches: 湄公河 Méigōng hé.
• Khmer: មេគង្គ Mékôngk [meekoŋ], ទន្លេមេគង្គ Tônlé Mékôngk [tʊənlee meekoŋ], ទន្លេធំ‎ Tônlé Thum [tʊənlee tʰom] ("Great River").
• Lao: ແມ່ນ້ຳຂອງ, [mɛː nâːm kʰɔ̌ːŋ], ນ້ຳຂອງ [nâːm kʰɔ̌ːŋ].
• Thai: แม่น้ำโขง, [mɛ̂ː náːm kʰǒːŋ].
• Tibetan: རྫ་ཆུ་; Wylie: rDza chu; ZWPY: Za qu
• Vietnamese: Sông Mê Kông (pronounced [soŋm mekoŋm]), Sông Lớn ("Great River", [soŋm lə̌ːn]), Sông Cửu Long ("Nine Dragons River", [soŋm kɨ̃w lɔŋ]).

Mekong

Mekong is a river in mainland China and Indochina. 10.-It is the world's longest river long and 7.-Asia. Its length is estimated at 4909 km (3050 mi) and drains an area of ​​795,000 km2 (307,000 square miles), releasing 475 km3 (114 cu MI) of water per year.

Since the Tibetan plateau, this river runs through China's Yunnan province, Burma, Laos, Thailand, Cambodia and Vietnam. Laos, Thailand, Cambodia and Vietnam established the Mekong River Commission in 1995 to assist management and the coordinated use of resources of the Mekong. In 1996, China and Burma has become a "dialogue partner" is the MRC and the six countries now jointly co-operation.

Seasonal variations in the flow and the presence of rapids and waterfalls of the river navigation are very difficult.