Mekong river boat
The Mekong River is one of the world's great rivers. Originating in Tibet, not far from the source of the Yangtze River, it tumbles down through the Himalayas and southern China into Southeast Asia and flows along the borders of Laos, Burma and Thailand through the heart of the Golden Triangle into Cambodia, where it flows in one direction in the wet season and the opposite direction in the dry season. It finally empties into the South China Sea at the Mekong Delta in Vietnam. Its source in Tibet as not discovered until 1994.

The Mekong River goes by many names. It is known as Lancang Jiang (Turbulent River) in China, the Mae Nam Khing in Thailand, Myanmar and Laos, Tonle Than (Great Waters) in Cambodia and Cuu Long (Nine Dragons) in Vietnam. It is also known as River of Stone, Dragon Running River, Mother River Khong, and Big Water.

The Mekong is the longest river in Southeast Asia, the 12th longest in the world and the 10th largest in terns of volume. With about half of its length in China, it flows for 4,620 kilometers (2,870 miles) and provides food and water for 60 million people and disgorges 475 billion cubic meters of water each year into the South China Sea.

The Mekong River is one of the wildest rivers in he world and is surprisingly undeveloped for such a large river. There are no large cities or industrial zones along its banks. It is not dammed. Until 1994 there were note even bridges across the lower stretches of it. For the most part the it is brown and muddy and still wild and free. The Upper Mekong features turbulent rapids, steep gorges and long section with no people. Often the only way to cross it is on cables strung between cliffs. The Lower Mekong River is calmer and more placid and incredibly wide in some places.

The Mekong flows through some poorest countries and regions in the world. For many the countries that border it development of the river is vital to the development of the country. China wants to develop the river to help the impoverished Yunnan Province. Around 60 million people depend on the river and its tributaries for food, transport and many other aspects of their daily lives.China has placed three dams across the upper reaches of the Mekong and more are planned. But otherwise the mainstream flows free (some major tributaries have dams). The Mekong River Commission (MBC) is an organization with representatives from Cambodia, Thailand, Laos and Vietnam committed to water utilization, basin development and environmental protection. Myanmar and China are not members just observers.

A good book on the river is “Mekong “ by Edward AA. Gargan (Knopf, 2002) written by a former correspondent for The Times. “Great Mekong Subregion Atlas of the Environment “ by the Asian Development Bank and United Nations Environmental Programme is well written and contains excellent photographs, charts and maps.

Route of the Mekong River

The Mekong River is 4,220 kilometers long and is one of the 12 great rivers of the world. From its source in the Tibetan plateau, it flows through the Tibet and Yunnan regions of China, forms the boundary between Laos and Burma as well as between Laos and Thailand, divides into two branches--the Song Han Giang and Song Tien Giang--below Phnom Penh, and continues through Cambodia and the Mekong basin before draining into the South China Sea through nine mouths or cuu long (nine dragons).

The river is heavily silted and is navigable by seagoing craft of shallow draft as far as Kompong Cham in Cambodia. A tributary entering the river at Phnom Penh drains the Tonle Sap, a shallow fresh- water lake that acts as a natural reservoir to stabilize the flow of water through the lower Mekong. When the river is in flood stage, its silted delta outlets are unable to carry off the high volume of water. Floodwaters back up into the Tonle Sap, causing the lake to inundate as much as 10,000 square kilometers. As the flood subsides, the flow of water reverses and proceeds from the lake to the sea. The effect is to reduce significantly the danger of devastating floods in the Mekong Delta, where the river floods the surrounding fields each year to a level of one to two meters. *

The Mekong River flows through a narrow, 200-kilometer-long gorge in southern China and along the Myanmar-Laos. From the tripoint of China, Burma (Myanmar) and Laos the river flows southwest and forms the border of Burma and Laos for about 100 kilometres (62 miles) until it arrives at the tripoint of Burma, Laos, and Thailand. This is also the point of confluence between the Ruak River (which follows the Thai-Burma 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 is notorious as a drug producing region.

As one travels south on the Mekong its become easier to navigate and higher numbers of greater varieties of boats appear. From the Golden Triangle tripoint, the Mekong turns southeast to briefly form the border of Laos with Thailand. It then turns east into the interior of Laos, flowing first east and then south for some 400 kilometres (250 mi) before meeting the border with Thailand again. Once more, it defines the Laos-Thailand border for some 850 kilometres (530 mi) as it flows first east, passing in front of 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 Khone Falls the river cascardes over rocks and separates into several branches, divided by forested islands, before it enters Cambodia.

The Mekong River flows through the east-central portion of Cambodia. Over much of its course it occupies an elevated bed paralleled by natural levees. Beyond the levees are huge depressions known as “beng “. The Mekong River is navigable from the sea by small ocean-going vessels as far as Phnom Penh. Shallow draft boats are necessary to further upstream. The northern Mekong River area of Cambodia is fairly undeveloped. There are some stretches where the villages are more than 30 kilometers miles apart. River traffic is light. The main fishing season is after the rainy season ends in September and the fish begin migrating northward. Villages use scoop nets to gather small, silvery fish.

Mekong River Basin

Foot bridge over the Mekong
The Mekong basin cover an area the size of France and Germany. More than 80 percent of the people that live in the Mekong River basis in rely on the river for agriculture or fishing. More than 41 percent of the land in the heavily populated Lower Mekong basin is used for agriculture, which accounts for 90 percent of all water use. In the forested uplands of the region, with a prime teak tree worth $20,000 or more, it is no surprise that illegal logging is a problem.

Eleanor J. Sterling and Merry D. Camhi wrote in Natural History magazine, The Mekong’s name translates from Lao as “mother of the waters.” It’s no wonder: the river snakes some 3,000 miles from its headwaters on the Tibetan Plateau to its outlet through the Mekong River Delta into the South China Sea. It and the uncountable “feeder” rivers and streams in Cambodia, China, Laos, Myanmar, Thailand, and Vietnam make up the 300,000-square-mile Mekong River Basin. [Source: Eleanor J. Sterling and Merry D. Camhi, Natural History magazine, December 2007]

The five Southeast Asian countries—Thailand, Vietnam, Myanmar, Cambodia and Laos—and one Chinese province—Yunnan—that embrace the Mekong basin are home to about 270 million people, roughly the population of the United States, but it lies on land a forth of the size of the U.S. The vast majority of the people that live on the region depend on the river either directly or indirectly.

Kevin Short wrote in the Yomiuri Shimbun,“A watershed ecosystem, of course, pays no attention to national boundaries. Deforestation high in the uplands, for example , can impact water quality and fish resources far downstream. Recognizing they share a common limited resource base and therefore a common future, the concerned nations and province have fored the Greater Mekong Subregional Plan, a coordinated effort to encourage sustainable resource utilization while preserving biological and cultural diversity throughout the watershed.” [Source: Kevin Short, Daily Yomiuri, February 2005]

Geography of Southeast Asia

Much of what is considered Southeast Asia sits on a peninsula that juts out from below China. Its forest have traditionally been the source of teak and sandalwood and its mines have traditionally been sources of rubies and sapphires. Today it produces much of the world’s rubber, palm oil, coffee, tea and rice.

Six important rivers flow through the region, including the Irrawaddy in Myanmar; the Mekong in Thailand, Laos and Vietnam; and the Red River in Vietnam. Many Southeast Asians live along the water, Floating markets, coastal kampong villages and houses on stilts are all fixture of the region.

Southeast Asia lies at the convergence pint of three continental plates: the Eurasian Plate. the Indo-Australia Plate and the Philippine Sea Plate. Much of Southeast Asia was created when frgm,enst broke off of the supercontinent Gondwanaland 400 million years ago and were pushed dup against the Asian continent 200 million years ago. When the Indian subcontinent began colliding with Asia about 55 million years ago and pushing up the Himalayas it also pushed mountain ranges in Southeast Asia.

While the Indian subcontinent was pushing against Asia, climate changes caused sea levels to rise and fall creating land bridges the appeared when the water was low and disappeared when it rose. These changes shaped the landscape along eth costs and played a big part in how animals and plant were dispersed and new species were created.

During the last set of Ice Ages main of the islands in Southeast Asia were connected to the mainland by land bridges.

History of the Mekong

It is believed that Marco Polo may have set eyes on the Mekong River in the 13th century. The Portuguese Dominican missionaries Father Gaspar da Cruz was the first European to describe traveling on the Mekong River. He spent 1555 to 1557 in Cambodia. The Dutch explorer Gerrot van Wuystoof wrote about it in 1641

The French had ideas of using the Mekong to navigate through Southeast Asia into China but these dreams were dashed when an expedition led by Francis Garnier in the 1860s discovered a major obstacle, Khone Falls, in southern Laos. He suggested blasting a canal next to the canal but a short railroad was built instead but the effort led to only minimal increases of commerce on the river.

A treaty signed in 1893 by France and Siam designated it as the border between Thailand and Laos. In World War II, a number of battles were fought in the proximity of the Mekong in China. During the Vietnam War, The Gong Guo Bridge near Baoshan, Myanmar, built in the 1930s, was a key link to the Burma Road. Mekong Delta in particular was the site of some bloody guerilla warfare as was the case with the Vietnam War in the 1960s and 70s.

Khone Falls and Limits of the Mekong River as a Transport Route

Khone Falls (on the Mekong River along the Laos-Cambodian border) is the widest waterfall in the world according to the Guinness Book of Records. The series of rapids and falls are 6.7 miles wide, with a drop of 70 feet. The falls are most impressive at the end of the rainy season when the flow is 1.5 million cubic meters per second. This is more than any other fall in the world, and twice as much as Niagra Falls.

Known properly as Khônephapheng Falls, Khone is six mile chain of cataracts. There are two main cascades: Phapheng and Somphamit Falls and several smaller sets of rapids. In some places some flimsy bamboo platforms have been set up for fishermen to use. Don’t try to use them yourself. The magic manikhot tree that sits in the middle of the falls is said to have never been touched by human hands. The river cruise to the falls passes by numerous islands and temples with saffron-robed monks.

The falls are one of the reasons why the Mekong River was one of the last rivers to be explored and developed. Fish amazingly can make their way up the falls but boats can’t. It dashed the hopes of French hoping to use the Mekong River as a transportation link to China.

The French built a 14-kilometers railway so that goods could be moved across two islands to bypass the falls. Cargo at one end of the railway was hoisted from boats and placed on railcars and unloaded back onto to boats at the other end of the line. Sometimes entire boats were lifted and put on railway cars The railroad operated until the end of World War II and was the only railroad built in Laos. After the war the rails were carried away by villagers. All that remains really are two piers, a bridge between the two islands, remains of sleepers and gravel and a rusting steam locomotive. On Khone Island you can hike on part of the old railway bed.

Greater Mekong Sub-region (GMS)

Greater Mekong Sub-region (GMS) is comprised of five six countries (Thailand, Vietnam, Myanmar, Laos and Cambodia) and one Chinese province (Yunnan) that share the Mekong River. Cooperation in the Greater Mekong subregion, led by the Asian Development Bank, began in the 1990s and has helped unite an area that for a long time was divided by longstanding conflicts. In 2005, Thailand, Vietnam, Laos and Cambodia signed an agreement to standardize and accelerate border crossings to facilitate trade. The agreement shortened border crossing formalities that previously took three hours to a day to just 30 minutes for trucks and five minutes for passenger cars.

Takashi Shiraishi wrote in the Yomiuri Shimbun: “Thailand is the hub of the Greater Mekong Subregion (GMS). All three GMS economic corridors--the North-South Corridor between Kunming, Yunnan Province, and Bangkok via Laos, the East-West Corridor from Vietnam to Thailand via Laos and Cambodia, and the Southern Corridor--lead to Thailand. Further infrastructure development in Bangkok, growth of industrial clusters in the areas around the Thai capital and trade promotion under the framework of free trade agreements, among other policies, will greatly contribute to Thailand's economy once the GMS successfully emerges as an integrated regional market. [Source: Takashi Shiraishi, Yomiuri Shimbun, October 10, 2011]

China has been helping GMS countries build expressways, high-speed railway lines and hydropower stations and improve power grids. These Chinese endeavors can be a big plus for Thailand, which wants the GMS developed as an attractive market. It makes sense for Thailand to enhance its partnership with China. China has been taking a "hub-and-spokes" approach to the GMS area. It regards the broad north-south linkage, stretching from China--Yunnan Province and the Guangxi Zhuang Autonomous Region--to Vietnam, Thailand and Myanmar as the "hub" of its GMS economic development. For the "spokes," China is radially extending its reach to various places that dot the region along the main linkage. For the GMS area to facilitate regional economic integration and growth, it is essential for all mainland Southeast Asian countries to be linked horizontally and strengthen their mutual economic relations.

Flow of the Mekong River

Harmony Patricio, a conservation biologist and the conservation director at FISHBIO, told “One unique thing about the Mekong is that it has the highest range of flows of any river on Earth. The difference in flows between the wet season and the dry season is immense. During the rainy season, the water levels rise and deposit a lot of nutrients and sediments along the banks. [Source: Jeremy Hance,, April 23, 2013 |~|]

During spring melt and the monsoon season from May to October, the Mekong became a raging torrent, sometimes producing a flood wave that is 46 feet high. Annual floods often kill dozens of people. Floods in Cambodia and Vietnam in 2000, killed 500 people and wiped out herds, crops and orchards. At the end of the dry season in March, April and May the river level can drop as much as 40 feet in some places, exposing large rocks and sand bars, and making navigation even in small boats difficult.

Three Parallel Rivers in Yunnan, China

The Three Parallel Rivers in Yunnan is a UNESCO World Heritage Site. Here the upper reaches of three of Asia's mightiest rivers — the Yangtze, Mekong, and the Salween — flow parallel to one another within a 55 mile band, divided by high mountain ridges. The Yangtze river, known in this area as the Jinsha, marks the boundary between Tibet and Kham. The Mekong is known as the Lancang. The Salween is called the Nujiang. “Jiang” is the Chinese word for river. The area is stunningly beautiful but rarely visited because the terrain carved by the rivers is so severe and rugged.

Fed by monsoon rains, the Yangtze, Mekong and Salween all sweep east of the Himalayas then drop due south, parallel to one another, before heading off in different directions. The gorges of the upper Yangtze, Mekong and Salween are among the deepest in the world, each twice the depth of the Grand Canyon, and reaching three kilometers in some places. Each gorge is separated from the others by towering mountains with more than a hundred peaks over 5,000 meters.

Described by the United Nations as the “epicenter of Chinese biodiversity,” the Three Parallel Rivers region is home to 6,000 vascular plant species, 30 species of timber trees, and 500 medicinal plants. Among the 173 species of mammal are clouded leopard and red gorel. More than 440 species of birds have been seen here. The 300,000 human inhabitants include more than a dozen ethnic groups. Among these are Tibetans, Naxi, Lisu, Yi and Nu, divided by mountains and uncrushable rivers.

The area was not explored by Westerners until the 1920s and 1930s. The first roads were gouged into the area to exploit the area’s timber in the 1950s. Entire mountainsides of old growth forest were clear cut. By the mid 1990s 80 percent of the regions’ income came from timber. Logging was cut back in the late 1990s partly in response to flooding on the Yangtze — that killed 4,000 and left more than a million homeless — that was blamed on deforestation-caused erosion.

By the late 1990s tourism began making inroads into the region and quickly displaced logging as the main money earner. People also began making money from harvesting medicinal herbs and matsutake mushrooms to export to Japan. Now the biggest issue concerning the region is how extensively to dam to the Jinsha, Lancang and Nu. The Jinsha has four dams under construction as of 2009. The Lancang already has three. Two are under construction and nine more are proposed. There are two on the Nu and a plan put on the table in 2003 calls for 13 more.

There are plans to build 100 dams in Sichuan and Yunnan in the Three Parallel Rivers area, where three great rivers. The plan calls for more than a dozen dams larger than the Grand Coulee dam and one that will be the tallest in the world. Even though the dams are in remote mountainous areas they are set to displace 1 million people.

Mekong River in Laos

The Lao PDR is criss-crossed with a myriad of rivers and streams. The largest is the Mekong River, flowing for 1,898 kilometers from the North to the South, with 919 kilometers of the river forming the major portion of the border with Thailand. It is estimated that some 60 percent of all the water entering the Mekong River system originates in Laos. These rivers and streams provide great potential for hydropower development with 51 percent of the power potential in the lower Mekong basin contained within Laos. Mekong River is navigable much of length but is not navigable between the sea and Laos because of Khone Falls in southern Laos. The Nam Ou, Na That and Nam Ngum are large tributaries of the Mekong River.

The Mekong River and its eastern tributaries drain all of Laos with the exception of Samneua Province in the northeast. The 1,600 kilometers of navigable water of the river that passes through Laos or along its border is the longest transportation and communication route in the country. But rapids in the far north and far south effectively cut Laos off from the sea and cross-border and international commercial possibilities.

Most of the western border of Laos is demarcated by the Mekong River, which is an important artery for transportation. The Khong falls at the southern end of the country prevent access to the sea, but cargo boats travel along the entire length of the Mekong in Laos during most of the year. Smaller power boats and pirogues provide an important means of transportation on many of the tributaries of the Mekong. The Mekong has thus not been an obstacle but a facilitator for communication, and the similarities between Laos and northeast Thai society--same people, same language--reflect the close contact that has existed across the river for centuries. Also, many Laotians living in the Mekong Valley have relatives and friends in Thailand. Prior to the twentieth century, Laotian kingdoms and principalities encompassed areas on both sides of the Mekong, and Thai control in the late nineteenth century extended to the left bank. Although the Mekong was established as a border by French colonial forces, travel from one side to the other has been significantly limited only since the establishment of the Lao People's Democratic Republic (LPDR, or Laos) in 1975. *

With an absense of railraods and a shortage of good roads the Mekong River is a vital transportation link in Laos. All of the country’s major cities and settlements are located on or near its banks. Flooding deposits rich top soil on its banks. The narrow flood plain is one of the main wet rice growing areas.

The Mekong River flows through a narrow, 200-kilometer-long gorge in southern China and along the Myanmar-Laos. From the tripoint of China, Burma (Myanmar) and Laos the river flows southwest and forms the border of Burma and Laos for about 100 kilometres (62 miles) until it arrives at the tripoint of Burma, Laos, and Thailand. This is also the point of confluence between the Ruak River (which follows the Thai-Burma 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 is notorious as a drug producing region.

As one travels south on the Mekong its become easier to navigate and higher numbers of greater varieties of boats appear. From the Golden Triangle tripoint, the Mekong turns southeast to briefly form the border of Laos with Thailand. It then turns east into the interior of Laos, flowing first east and then south for some 400 kilometres (250 mi) before meeting the border with Thailand again. Once more, it defines the Laos-Thailand border for some 850 kilometres (530 mi) as it flows first east, passing in front of 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 Khone Falls the river cascardes over rocks and separates into several branches, divided by forested islands, before it enters Cambodia.

Mekong River in Cambodia

The Mekong River Cambodia’s largest river, dominates the hydrology of the country. The river originates in mainland China, flows through Myanmar, Laos, Thailand before entering Cambodia. At Phnom Penh, with alternative arms, the Bassak River from the south, and the Tonle Sab River linking with the " Great Lake " itself –Tonle Sap – form northwest. It continues further southeastward to its lower delta in Viet Nam and to the South China Sea.

The Mekong River in Cambodia flows southward from the Cambodia-Laos border to a point below Kracheh city, where it turns west for about 50 kilometers and then turns southwest to Phnom Penh. Extensive rapids run above Kracheh city. From Kampong Cham the gradient slopes very gently, and inundation of areas along the river occurs at flood stage--June through November--through breaks in the natural levees that have built up along its course. At Phnom Penh four major water courses meet at a point called the Chattomukh (Four Faces).

The section of Mekong River passing through Cambodia lies within the topical wet and dry zone. It has a pronounced dry season during the Northern Hemisphere winter, with about 80 percent of the annual rainfall occurring during the southwest monsoon in May-October. The Mekong River average annual flow at Kratié of 441 km3 is estimated as 93 percent of the total Mekong run-off discharge into the sea. The discharge at Kratié ranges from a minimum of 1,250m3/s to the maximum 66,700m3/s.

Tonle Sap and the Mekong River

The Tonle Sap (north of Phnom Penh in Cambodia) is the largest freshwater lake in Southeast Asia at the end of the wet season but is only a large lake in the dry season when it shrinks to a fraction of its wet season size Stretching almost all the way from Phnom Penh to Angkor Wat, it provides water for half of Cambodia's crops, and yields fish that supplies Cambodia’s population with half its protein It is also one of the country’s most important transportation links.

Tonle Sap lake—which is connected to the Mekong by a short river also called Tonle Sap—alternately feeds, and feeds from, the Mekong River. During raining season from June to October, the lake is fills with water flowing from the northward-flowing Mekong River and becomes 14 meters deep in some places and expands it surface area to around 10,000 square kilometers. In dry season from November to May its shrinks in size to 3,000 square kilometers, with an average depth of only two meters as water flows out from the lake when the Mekong changes course and flows south.

In the Angkor era, Tonle Sap was to the Khmers what the Nile was to the Egyptians: a source of abundance that freed labor to produce grand monuments and create a high level of culture. In the dry season, the Khmers captured the lake’s retreating waters and used them to irrigate crops, and thus were able to grow two or three crops a year. In the wet season, they used the waterway’s advancing waters to carry quarried stones to build Angkor’s great temples. In the Khmer language "Sap" means “lake.”

Flooding Cycle of Tonle Sap

During the rainy season, from June to November the Mekong River reverses its flow into the lake causing it to expand to more than six or seven times its normal size of approximately 2,600 square kilometers. It becomes a vast inland sea. In June, with monsoon rains swelling the Mekong, excess water is pushed into the Tonle Sap that then drains back upstream into the lake, flooding the surrounding low plains. By monsoon's end, in November, the pressure is relieved and the Tonle Sap reverses course and returns to the direction of flow expected of it. However, the waters take several more months before they begin to recede, and it is not until February that Tonle Sap Lake begins its return to normal size.

Tonle Sap is like a big bowl that fills with water when the Tonle River flows into it and empties when the Tonle River changes direction, as it does every year, and flows out of it. The Tonle River is part of the Mekong River system, which swells with monsoon rains and snow melt from the Himalayas in the wet season, reaching a flood discharge of 40,000m3/s at Phnom Penh. By about mid-June, the flow of Mekong and the Bassak River fed by monsoon rains increases to a point where its outlets through the delta cannot handle the enormous volume of water, flooding extensive adjacent floodplains for 4-7 months. At this point, instead of overflowing its backs, its floodwaters reserve the flow of the Tonle Sap River (about 120 kilometers in length), which then has the maximum inflow rate of 1.8m/s and enters the Grate Lake, the largest natural lake in Southeast Asia, increasing the size of the lake from about 2,600 km2 to 10,00 km2 and exceptionally to 13,000 km2 and raising the water level by and average 7m at the height of the flooding. This specificity of the Tonle Sap makes it the only "river with return " in the world.

By September the of flow of the Mekong River is ten times what it is in the dry season, with much of the excess water flowing into the Tonle River, which in turn fills up Tonle Sap. After that the monsoon rains stop the amount of water flowing down the Mekong is greatly reduced. At a critical point — after the Mekong’s water crest (when its downstream channels can handle the volume of water) — the water pressure from Tonle Sap exceeds the pressure from the Mekong River and the Tonle River changes direction and begins flowing towards the Mekong River, draining much of the water out of Tonle Sap. By the end of dry season, Tonle Sap has lost most of its water and resembles a swamp crisscrossed by channels.

The Great Lake then acts as a natural flood retention basin. When the floods subside, water starts flowing out of the Great Lake, reaching a maximum outflow rate of 2.0m/s and, over the dry season, increase mainstream flows by about 16 percent, thus helping to reduce salinity intrusion in the lower Mekong Delta in Viet Nam. By the time the lake water level drops to its minimum surface size, a band 20-30 kilometers wide of inundate forest is left dry with deposits of a new layer of sediment. This forest, which is of great significance for fish, is now greatly reduced in size through salvation and deforestation. The area flood around Phnom Penh and down to the Vietnamese border is about 7,000 km2.

The depth of Tonle Sap peaks at around 45 feet in September, when area of the lake covers as much a 4,500 square miles (11,700 square kilometers). In the dry season the depth of the lake can drop to as low as three feet. Depending on the rainfall and snow melt amounts Tonle Sap can be as much as 15 times bigger in the wet season than it is in the dry season. In the wet season vast amounts of farmland and entire forests are submerged and stilted houses and floating villages lie in the middle of the lake. When the water retreats it leaves behind layers of fertile silt and maroons the stilted houses and floating villages on land.

Mekong River Delta

The Mekong Delta (about 3 hours south of Saigon in Vietnam) is huge delta created by massive amounts of silt, some of it originating in the Himalayas, carried downstream by the Mekong River and deposited in southernmost part of Vietnam, where the great river empties into the South China Sea. About 10,000 square kilometers of the delta are under rice cultivation, making the area one of the major rice-growing regions of the world. The southern tip, known as the Ca Mau Peninsula (Mui Bai Bung), is covered by dense jungle and mangrove swamps.

The Mekong Delta is a low-level plain not more than three meters above sea level at any point and crisscrossed by a maze of canals and rivers. So much sediment is carried by the Mekong's various branches and tributaries that the delta advances sixty to eighty meters into the sea every year despite waves, typhoons and tides that gobble it up. An official Vietnamese source estimates the amount of sediment deposited annually to be about 1 billion cubic meters, or nearly 13 times the amount deposited by the Red River.

Flat, hot and green, the Mekong Delta is Vietnam's most important agricultural region. Much of the area is covered by rice paddies that are irrigated by delta water and fertilized by delta silt. Many paddies and farms produce three crops of rice a year, enough to feed the entire country, with some left over to export, Almost half of Vietnam’s exported rices comes from the Mekong Delta. Other products from the region include sugar cane, coconuts, pumpkins, various kinds of fruit, fish and snakes. There also large numbers of catfish and shrimp farms.

The delta covers an area of about 40,150 square kilometers (15,500 square miles), half of it under cultivation, and home to a fifth of Vietnam’s 80 million people. Many people get around by boat and Mekong taxis (wagons pulled by motorcycles) and live in villages and towns, some of which have floating markets, along the and small rivers that lace the delta. Many boats are manned by women in conical hats who stand up when they row. Women also dominate the markets and trade.

The Mekong Delta wasn’t really inhabited until the 19th century. During the Vietnam War it was where most many of U.S. army’s infamous Search and Destroy missions took place. The level of the water varies according to daily tides, dredging operations and seasonal variations (ranging from 38,000 cubic meters a second in September to 1900 feet a second in April). Birdlife, including ibises, storks and spoonbills, is plentiful and saltwater crocodiles are found in the southern part of delta. During the rainy season there can be big floods. Sometimes the roadbeds are the only high ground in huge lakes.

Before the Mekong River enters Vietnam it follows a pretty direct course but after it enters Vietnam it begins meandering and spreading out. It enters the country as two channels which the Vietnamese call Tien Giang (Upper River) and Hau Giang (Lower River). As it moves along it branches out further. By the time it reaches the South China Sea it has seven main branches. Two others have silted over. The Vietnamese, mindful than nine is an auspicious number, call these branches the Nine Dragons.

Connecting and running off of these branches are streams and canals, which together have an estimated length of 3,600 kilometers—almost the length of the Mekong River itself—and are crossed by fragile-looking bridges made of bamboo and mangrove branches lashed together with vines. In southern part of the delta is the U Minh Forest, an extensive area of mangroves and swamp forest, where an extremely rare Javan rhinoceros was discovered in the late 1990s. Large parts of forest have been deforested and transformed into shrimp farms.

People Living on the Mekong River

The Mekong River Basin plays a vital role of the many communities that live along it. Harmony Patricio, a conservation biologist and the conservation director at FISHBIO, told "The river means everything to the people living in the basin, especially in rural areas. It's their source of life. More than 60 million people depend on the fish for food, which typically accounts for more than half of their animal protein. There's not really a substitute for that. People also use the river for transportation, for their household water supply, and for growing rice and farming." [Source: Jeremy Hance,, April 23, 2013 |~|]

“In the dry season, the water level goes down and people in rural areas have this really rich soil where they plant riverside gardens, which are an important source of vegetables like beans and corn. So in the dry season, maybe they can't catch as many fish, but they have these riverside gardens that are really productive. The river also delivers huge amounts of sediment to the delta in Vietnam, which supports some of the world's highest rice production and the nutrients in the sediment create a marine plume that contributes to high fish abundance in the ocean off the coast of the delta. Scientists are just now starting to understand the role of this marine plume for fish production. |~|

“You also have many different people involved in fishing—men, women, and children—at all different scales. People will fish for just 20 minutes for subsistence, just enough to get dinner for their family that night. Then there are big commercial operations in the Tonle Sap that pull in huge hauls. Trying to measure and research the harvest at these different scales is really challenging. |~|

Fishing on the Mekong River

Fish caught in the river are an important source of protein for an estimated 65 million people. Many of these fish rely on the natural annual flood cycle of the river to reproduce. In Laos, Thailand , Cambodia and Vietnam, fishermen catch about 1.3 million tons of fish a year, four times the yearly catch in the North Sea. One of the riche fish ground is the Siphandone, or Four Thousand Islands, area between Laos and Cambodia.

Fish stocks have been reduced by overfishing, habitat destruction and development. Large fishing operations—some fo them legal, some of them not—employ large nets and traps that can catch hundreds of thousands of fish ay a time. Some people catch fish with bed-sheet-size butterfly nets that they dip into rice paddies flooded by the river.

Transportation on the Mekong River

The Mekong River and its tributaries provide crucial transportation links in Laos, Thailand, Cambodia and Vietnam. Between Simao in Yunnan and Jinghong on Laotian border the river is navigable. The river runs for 786 kilometers between Simao and Luang Prabang in Laos. Passage between Cambodia, Vietnam, Laos and Thailand is blocked by Khone Falls in Laos, one of the world’s most powerful cataracts. The series of rapids and falls drops 20 meters (70 feet). The river is eight miles wide near this spot.

The idea of using the Mekong River as the hub of a major transportation hub became a possibility in the 1990s when the peace was finally achieved in Cambodia and the insurgency in Laos became more manageable. In the early 1990s there were no bridges over the Mekong River. Now there are several, in Vietnam and between Laos and Thailand.

Myanmar, Thailand, China and Laos has signed an agreement to open a navigation route along the upper reaches of the Mekong River. Under the agreement the four countries allowed commercial navigation across each other’s borders. There are plans to make an access route from southern China to the Indian Ocean via the Mekong River.

China is currently involved in dredging upper parts of the river to make them navigable. In the dry season, 150-tons can not navigate these sections. Dredging will remedy this. Dredging between Vientiane and Simao in Yunnan Province in China will make section of the river capable of handing 2,000 ton ships throughout the year except for a couple weeks in the dry season when water levels are exceptionally low. Both the Chinese and Laotian governments support the project as a means of promoting economic growth through increased trade.

Many locals oppose the dredging operations, They complain large ship creates wakes and waves that can sink smaller boast and worry that large Chinese boats will take away cargo business from smaller local boats and flood the market with cheap Chinese goods and produce. Environmentalist say the dredging damagesriver banks, destroys fish stocks and threatens endangered animals. The dredging operations involves using explosive to blast apart shallow rocks, reefs and shoals and widen channels.

Types of Boats Used by Travelers on the Mekong River

Speed Boats called “heua wai “ are used primarily between Luang Prabang and Hat Sa (Prongsali) on the Nam Ou River and between Vientiane and Huay Xai on the Mekong Rivers. They are able to cover a distance in five or six hours what might take a ferry a couple of days but are very dangerous, noisy and uncomfortable. Passengers sit on wooden benches and wear life jackets and crash helmets. They are so noisy passengers on other boats can hear them when they are almost a mile away. Speedboats can take up to six passengers and are generally rented for about $23 a hour, a cost that can be split among several passengers. A trip between Vientiane and Luang Prabang can done be done with six people for about $25 per person.

Accidents involving “heua wai “ are very common. Accidents occur on a weekly basis and often involve fatalities. Because the boats are very light and travel at high speeds, the results can be quite nasty if they hit a rock, sand bar or branch in the river, which is not all that hard to do. Sometimes a bow wave from a large boat is enough to flip them over.

Long-Tailed Boats (named after drive shaft which extend beyond the back of the boat and connects the an automobile engine to a propeller) are used by locals and tourists to get around the rivers of Laos. Tourist generally travel on boat trips sponsored by travel agencies and locals get around on boats that run scheduled routes like buses. The fares for local boats are quite reasonable. The tours aren't very expensive either. Many of the long tailed boats used in Laos are long narrow river taxis with a covering for protection form the sun and rain, A boat that carries eight to 10 passengers can be hired for about $10 an hour

Cargo Boats make the trip between Vientiane and Luang Prabang in about three to four days down river and four to five days upriver.

Traveling on the Mekong River between Stung Treng, Cambodia and the Laos border

The Mekong River between Stung Treng and the Laos border is very light on population and heavy on beautiful scenery. Boulder outcroppings, numerous sets of rapids, swirling pothole currents, wide sweeping stretches of river and forested landscape along the banks all await the boat traveler. It makes for a great trip, either for the traveler that wants to continue on to Laos or for those wanting to enjoy a wild stretch of the Mekong in Cambodia. [Source: ] The trip is difficult to downright impossible to make on this shallow stretch of the Mekong during the dry season, with countless sunken islands and a virtual forest of trees growing right in the middle of the river. The trip becomes an obstacle course for the boat drivers this time of the year, as they carefully try to choose the best way to guide their craft through the maze that nature has created without losing a propeller to the river. The best time of the year to take this trip is from May to November when sufficient upstream rains have raised the river to a level that allows the boats to pass through carefully.

If you want a faster journey, approach one of the small fiberglass boat operators, the ones that have the 40-hp outboard motors-they want US$ 20-$25 (one-way) to make the trip- but if you are looking for a quick trip or fast fun, the trip time going upriver is cut down to only 1½ hours. The slow boats are fast enough coming back downstream so you could save money by grabbing one of those on the return trip. For those wanting to cross into Laos using this route you will need a Laos’s visa in your possession and you also need to stop at the main police station in Stung Treng town to get a letter of permission to cross the border at this point. This is shown to Cambodian immigration will not let you stamp out of the country without this.

Image Sources: Wikimedia Commons

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Global Viewpoint (Christian Science Monitor), Foreign Policy, Wikipedia, BBC, CNN, NBC News, Fox News and various books and other publications.

Last updated August 2020

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