Mekong

The Mekong or Mekong River is a very long river in East Asia and Southeast Asia. It is the world's twelfth-longest river and the third-longest in Asia. The river stretches about 4,909 kilometers (3,050 miles) and drains an area of 795,000 square kilometers (307,000 square miles).

The Mekong begins in the Tibetan Plateau and flows through several countries, including Southwest China (where it is called the Lancang River), Myanmar, Laos, Thailand, Cambodia, and southern Vietnam. Along its path, the river has areas with fast-moving water, called rapids, and waterfalls, which make it hard to travel by boat.

Even with these challenges, the Mekong is an important trade route connecting different parts of Asia. However, building hydroelectric dams along the river in recent years has caused problems for plants, animals, and people, including making drought worse.

Names

The name Mekong comes from the words Me and Kongkea. Me means "Mother" in the Khmer language, and Kongkea is a word borrowed from the Sanskrit language, referring to the sacred Ganges River in India.

Over time, the name changed from Me-Kongkea to Me-Kôngk, and Western cartographers later called it Mekong. In Thai and Lao languages, the river is called Mae Nam Khong. The word Khong is an old word for "river" that came from Austroasiatic languages.

The Mekong has many names in different languages. For example:

• From Thai: แม่น้ำโขง, mɛ̂ɛ-náam-kǒong, or just แม่โขง, mɛ̂ɛ-kǒong.
• From Lao: ແມ່ນ້ຳຂອງ, mǣ nam khǭng, or just ນ້ຳຂອງ, nam khǭng.
• From Vietnamese: Sông Mê Kông or Sông Cửu Long (Nine Dragons River).
• From Mandarin Chinese: 湄公河, Méigōng Hé.
• From Burmese: မဲခေါင်မြစ်, mai:hkaungmrac.
• From Khmer: ទន្លេធំ Tônlé Thum ("Big River") or មេគង្គ Mékôngk.
• From Khmuic: [ŏ̞m̥ kʰrɔːŋ̊], which means 'canal river'.

Course

The Mekong River begins as a small stream called the Za Qu in the Tibetan Plateau and becomes known as the Lancang River in China. It flows through Southwest China, Myanmar, Laos, Thailand, Cambodia, and into southern Vietnam.

Along its journey, the Mekong passes through many landscapes and countries. It forms borders between some nations and passes near important cities. Near Phnom Penh in Cambodia, it connects with the Tonlé Sap lake, which sometimes sends water into the river and sometimes receives water from it during floods. After Phnom Penh, the river splits into different branches as it enters Vietnam, creating a wide delta area.

Drainage basin

The Mekong Basin is split into two parts: the upper Mekong basin and the lower Mekong basin. The upper basin is in Tibet, Yunnan, and eastern Myanmar. The lower basin starts from Yunnan and goes down to the South China Sea. The biggest drop in the river happens in the upper basin, where it falls 4,500 meters before entering the lower basin.

The upper basin is small but contributes a lot of sediment to the river. In Yunnan, the river flows through deep gorges and has lost some of its forests. In the lower basin, there are many tributaries, especially in Laos and Thailand. The landscape changes a lot, affecting how the river flows. In Cambodia, the river spreads out and creates a delta in Vietnam.

The Mekong River’s flow changes along its course. In China, called the Lancang Jiang, snowmelt from the Tibetan Plateau feeds the river. Further down, the river gets water from many tributaries, especially in Laos and Thailand. The river’s flow is important for the countries it passes through, and changes in one part can affect others.

Geology

The Mekong River has unusual water patterns compared to other large rivers like the Amazon, Congo, and Mississippi. Most big rivers have simple branching patterns, but the Mekong's pattern is more complex. This complexity comes from the active and varied geological structure in its area.

The rise of the Tibetan Plateau millions of years ago helped create the monsoon rains that affect the Mekong. Studies show that the source of sediments in the Mekong Delta changed about eight million years ago, with more coming from Vietnam's Central Highlands today. The Mekong Delta formed over the last 6,000 years, growing out into the South China Sea. For much of its path, the Mekong flows through rocky channels, with wider floodplains only near Vientiane and Kratie. While the Mekong basin is generally stable, parts in northern Laos, northern Thailand, Myanmar, and China experience small earthquakes.

History

The Mekong River has played an important role in the lives of people living near it, often dividing them instead of bringing them together. Early settlements along the river date back to 210 BCE, with places like Ban Chiang showing advanced Iron Age culture. One of the earliest known civilizations was the Indianised-Khmer culture of Funan in the Mekong delta.

The first European to see the Mekong was the Portuguese António de Faria in 1540. Later, the French explored and eventually controlled parts of the region in the 19th century. In the 1970s, during wars in the area, many explosives sank into the river, creating dangers for people using the water. Today, countries along the Mekong work together to manage and protect the river through groups like the Mekong River Commission.

Natural history

The Mekong basin is one of the richest places for plants and animals in the world. Only the Amazon has more. Scientists have found many different kinds of plants, mammals, birds, reptiles, amphibians, and fish there. In fact, new species are still being discovered.

The Mekong River is special because it is home to some very large fish, like the giant freshwater stingray and the Mekong giant catfish. Sadly, many of these big fish are now rare because of dams, flood control, and overfishing. The river also used to have freshwater dolphins, but there are very few left.

Fisheries

The Mekong River has some of the richest water life in the world, second only to the Amazon. It is home to many different kinds of fish and other water animals, including very large fish like the giant freshwater stingray and the Mekong giant catfish.

Many people living near the Mekong depend on fishing for food and work. Fish and other water animals are an important part of their diet, especially in Laos and Cambodia. Fishing also helps people earn money and provides support when farming is difficult.

Dams

Main article: Hydropower in the Mekong River Basin

Dams in the Mekong River are built for making electricity, helping farms grow crops, and providing water. As of February 2024, many dams are spread across the river.

There are also several dams being built. In February 2024, one dam was under construction in Cambodia, three in the TAR, and fourteen in Laos.

Fifteen of these dams are on the main path of the Mekong River. Thirteen of these are in China, and two are in Laos. One more dam on the main river is being built in Laos, and another in China.

Navigation

The Mekong River has been a vital path for people and goods for thousands of years. Small boats have long connected communities along the river, and today the Mekong is becoming a key route for international trade, linking the six countries it flows through to each other and the rest of the world.

The river can be roughly divided into an upper and lower section. The upper Mekong, north of the Khone Falls in Laos, has narrower and more turbulent waters, making navigation challenging. Seasonal changes in water levels affect trade, with less cargo moving during low water seasons. Despite these challenges, the Mekong is an important trade route between Kunming and Bangkok, with about 300,000 tonnes of goods shipped each year. Trade is expected to grow, and new port facilities are being built to support this increase. In Laos, smaller boats carry goods like timber and farm products, while Thailand imports many items from China and exports things like dried longan and rubber.

In Vietnam and Cambodia, trade along the lower Mekong has grown, though it dipped in 2009 due to worldwide economic troubles. A new deep-water port in Vietnam has helped boost trade again, allowing large ships to travel directly to Europe and the United States. Several agreements between the countries that share the Mekong help ensure smooth trade and travel along the river. Plans to improve the river for bigger ships have been discussed, but some local groups worry these changes will not help local people as much as they will help big commercial ships.

Bridges

See also: List of crossings of the Mekong River

Construction of the Myanmar–Laos Friendship Bridge began on February 19, 2013. When finished, it will be 691.6 meters long with an 8.5-meter wide road for cars.

The First Thai–Lao Friendship Bridge links Nong Khai in Thailand to Vientiane in Laos. This bridge, which opened in April 1994, is 1,170 meters long and has two lanes for cars plus a railway in the middle. Plans were made in 2004 to extend the railway further into Laos, and this work is now done.

The Second Thai–Lao Friendship Bridge connects Mukdahan in Thailand to Savannakhet in Laos. It opened in January 2007 and is 1,600 meters long with two lanes for cars.

The Third Thai–Lao Friendship Bridge opened in November 2011, linking Nakhon Phanom Province in Thailand with Thakhek in Laos. It is part of a major road network called Asian Highway 3. China and Thailand worked together to build it and shared the cost.

The Fourth Thai–Lao Friendship Bridge opened in December 2013, connecting Chiang Rai Province in Thailand with Ban Houayxay in Laos.

Laos has one bridge that is not a border crossing. It is located at Pakse in Champasak Province and was finished in 2000. The bridge is 1,380 meters long.

The Kizuna Bridge is in Cambodia, in the city of Kampong Cham. It opened in December 2001 and helps connect Phnom Penh to farther areas.

The Prek Tamak Bridge opened in 2010, located 40 kilometers north of Phnom Penh.

Phnom Penh does not yet have a bridge being built, but two new bridges opened recently on another river, and the main road bridge to Ho Chi Minh City was made larger in 2010.

Another new bridge was completed at Neak Leung on the road to Ho Chi Minh City in 2015, with help from the Japanese government.

In Vietnam, the Mỹ Thuận Bridge opened in 2000, crossing near Vĩnh Long. Since 2008, the Rạch Miễu Bridge has crossed the river near Mỹ Tho.

Cần Thơ Bridge opened in 2010 and is the longest main span cable-stayed bridge in Southeast Asia. It crosses another channel of the Mekong called the Bassac (Song Hau).

Environmental issues

Climate change and many large dams are harming the Mekong River's natural balance. When dry periods end and floods begin, scientists do not fully understand how the dams change the way floodwaters move through the lower part of the river.

Water in towns and cities along the Mekong, like Vientiane in Laos, is not always cleaned properly before it goes back into the river. This pollution hurts the plants and animals that live in the water.

A lot of plastic—about 8.3 billion tonnes—ends up in the world’s oceans. The Mekong River is one of the main rivers that carries plastic into the sea.

Some scientists and groups are asking world leaders and the Mekong River Commission to use less power from dams. They suggest using solar power and other clean energy instead, which is now more affordable and quicker to set up.

Sand mining along the Mekong in Laos, Cambodia, and Vietnam changes how the river flows. This can make riverbanks unstable, reduce water and soil that reach floodplain areas, increase salt levels in the water, and disturb many plants and animals.

Mining for tin and rare-earth materials in areas like Karen and Shan states is also polluting the Mekong River area.