219th Meeting – Tuesday, February 12th  2002

'The Mekong Nobody Knows'

A talk and slide presentation by Steve Van Beek

Summary of Steve’s talk:

In 1995 and 1997 our Sino-American team – from the Chinese Academy of Sciences in Beijing and Earth Science Expeditions of Colorado – made a first descent of a 350-km portion of the Mekong River in Yunnan Province.

The team, composed of Chinese and American doctors, geologists, anthropologists, biologists, environmental planners and seismologists, sought to match disparate Russian, Chinese and American aerial maps to terrain. We also looked at the fault zones which might effect the safe construction of dams, land use, the relationship between river dwellers and their river and herbal medicine. We chose a river section unreachable and unparalleled by roads because we wanted to see the people and the landscape in a pristine state.

From its source on the Tibetan Plateau, the Mekong flows 4,400 kilometres through China, Burma, Thailand, Laos and Cambodia to the South China Sea off Vietnam. The Chinese portion measures about 1,500 km or 35% of the Mekong's entire length. Interestingly, the Salween, Mekong and Yangtze rise within a few hundred kilometers of each other. To reach the Lancang's headwaters in1999 we crossed the Yellow and the Yangtze rivers. We drove two days west from Kunming to the first concrete bridge to be built over the Mekong. It straddles the river between Yongping and Booshan on the old Burma Road, built during World War II to link Allied bases in Burma and Kunming.

The region is subject to violent earthquakes. French geologists believe that Yunnan's mountains resulted from the tectonic collision between India and Asia. Although we encountered marble, granite, travertine and other igneous and metamorphic stone – probably dating from an earlier era – much of the soil is sea bottom gravel. As in Nepal, this loose rock poses a huge sedimentation problem. On our road journeys we passed decade-old 10- and 20- metre high dams that had become waterfalls after sediment filled the reservoir to the brim.

It's an area rich in history. Just downstream from the huge Dragon's Teeth rapids are the remains of the Jihong Bridge, China's oldest bridge. Built in 105 BC, in 1475 it was rebuilt with 18 thick iron chains stretched across the 110-metre chasm. The bridge was destroyed by an earthquake in 1986. Yunnan holds 51% of China's plant and animal species. While there was abundant wildlife at the headwaters, including the rare snow leopard, we saw no wildlife along the lower stretches in Yunnan. Most of them have been eaten. The small amount of arable riparian land is utilized to the fullest with terraces running from the ridge tops to within 15 metres of the river. Yet, despite the adverse conditions, Yunnan's farmers are fortunate. Two thirds of China is mountains and plateaus unfavourable for agriculture. 25% of China lies above 500 metres elevation, too high to grow many crops. The mean annual temperature in 20% of China is 0ºC, a chill not conducive to agriculture. 30% of China receives less than 200 mm of rainfall per year. Thailand's annual average is 1.2 metres. To compensate, Chinese farmers practice intensive cultivation and share with Japan, Asia's highest rice yields; 6,300 kg/hectare, (Thailand's is 1,800 kg/hectare). Although 35% of the Mekong flows through China, only 20% of the water that enters the South China Sea originates there. Moreover, the land's ability to retain rainwater to support year-round cultivation is compromised by extensive deforestation. China's massive replanting scheme is replacing biodiverse forests with fast-growing cash trees like pines.

The Han, recent emigrants, are the dominant group and usually live in towns. Rural Han speak a dialect that our Mandarin-speaking Beijing Chinese found difficult to decipher. 26 of China's 56 national minorities live in Yunnan: the bulk of the Mekong's rural population is Bai and Yii. Speaking a Tibeto-Burman language, three million Yii inhabit mountainous areas. 'Yii" is a Han word meaning 'barbarian'. In the past, upriver Yii practiced slavery. Black Yii (referring to their costumes) were slave owners; White Yii were slaves. Modern Yii mine minerals and plant millet and corn high on the hillsides. 1.1 million Bai live near the Mekong and near Dali and Erhai, Yunnan's largest lakes. They plant two crops a year including rice, winter wheat, beans, millet, cotton, rape, sugar cane and tobacco. The three 60-metre high pagodas at Dali's Chongshen Temple were built by the Bai 1,000 years ago and are considered representative of the Bai architectural skill. Nominally Buddhists and worshippers of a 'communal god', they bury, rather than cremate, their dead.

What is immediately evident from a tour of a village is the extreme poverty. No electric lines or roads reach here, so people are, of necessity, self-sufficient. They cut and finish the wooden planks that clad their house and bake their own roof tiles. They use the most primitive of cultivation tools, herd pigs and buffalo and are experimenting with pineapple and rubber plantations. Its steep banks render the river of little use to the Mekong peoples. Crops are irrigated by rainfall. Some villages channel water high along a slope and into a pipe that funnels it into small turbines to supply village electricity needs.

Thus, the river plays only a small part in agriculture, nor can it be used to transport goods because of its ferocity. The Chinese call the Mekong the Lancang Jiang, 'the turbulent river', and do not venture into its rapids in their flimsy wooden boats. Only in the quiet sections do boats ferry people and goods from bank to bank. The river contains little biotic material so there are few fish of any size. For the moment, they use it for dams. The Manwan Dam, the first built on the Mekong River, was constructed in 1992. Despite environmental concerns about dams, one must consider that China now produces electricity by burning a brown coal that creates enormous health hazards. By comparison, hydro-electricity is clean. The problem is that the dams are in an earthquake zone. During our 1995 journey, an earthquake, its epicenter 160 km northeast of the Manwan dam, killed 200 people. In January 1996, a major earthquake leveled villages in Lijiang. A check of a seismic map reveals that the same fault line extends southwest and along the streambed, half a day below the Booshan Bridge. The newest dam, Dashaushan, was under construction when we passed it in 1997. Just below the dam the rocks change types, which is normally indicative of a strike and slip fault zone where earthquakes are likely to occur.

The Chinese plan to build 37 mainstream and tributary dams along the Mekong. The initiative has caused political problems because the government has indicated that it will not predicate its development policy on the wishes of its downstream neighbours. It refuses to join the Mekong River Commission, a four-nation forum for equitable distribution of the Mekong's water resources. In 1998, Chinese engineers blocked the river for four days to complete the Dashaushan cofferdam. Vietnam protested that it was losing US$100,000 a day from salt water intrusion into the delta, brine that would normally have been held at bay by fresh water flowing down the Mekong. The Chinese reportedly did not reply to their complaints. There is some potential for tourism but the ESCAP Ports and Inland Waterways Division proposes to blast rocks from the channel, a move rightly opposed by environmentalists.          

What does the future hold? Laying aside the matter of the hubris that leads engineers to build dams on fault lines, the question is whether life will improve for the Mekong's riparian people. Lands will be flooded, disease normally comes in the wake of reservoirs. Otherwise, because the people shy away from the ferocious river, the impact on their lives will be minimal. What is certain is that The Mekong Nobody Knows is being buried beneath reservoirs long before it has been entirely understood. If one believes that rivers are exploitable resources, then little will have been lost. If one views the river as a cultural entity – a narrative thread of the region's history, timeless since creation – then much will be lost. And we are seeing that transition within a single generation.