The Yarlung Zangbo River Gorge, which stretches 496 kilometres and has an average depth of more than 5,000 metres, presents a major challenge for many hardy adventurers.

The Yarlung Zangbo River (with a total length of 2,900 kilometres, of which 1,787 kilometres within the boundaries of the Chinese territory), which has its source on the Qinghai-Tibet Plateau, flows at the highest

elevation of any river in the world and consists of surging rapids and dangerous shoals.

The Yarlung Zangbo Grand Canyon

Everyone has reason to cheer the discovery of China's largest canyon. In early October 1998, the canyon was given its official name, Yarlung Zangbo Daxiagu (Yarlung Zangbo Grand Canyon). The Yarlung Zangbo River runs eastwards along the northern foothills of the Himalayas. The lower reaches of the river cut through the mountain range before making a sharp V-turn around Namjagbarwa Peak in Pai, Namling County, in eastern Tibet-the starting point of the Grand Canyon. The Yarlung Zangbo Grand Canyon has been confirmed as the largest in the world. It is 496.3 kilometres long, 56.3 kilometres longer than the Colorado Grand Canyon, previously considered the world's longest. It is 5 , 382 metres deep, much deeper than the 3 ,200 metres of Peru's Colca Canyon, previously known as the world's deepest canyon.

The discovery that the canyon was actually the largest in the world was formally announced by Chinese scientists on April 18 , 1994. The discovery of the canyon is a very important event that contributes to mankind's knowledge of nature. However, this is just the beginning. The canyon will become a tourism centre in eastern Tibet in the near future. This is a good chance for Tibet to develop tourism and its regional economy. The development of the canyon may offer a solution to the communications problem of Tibet's poor Motuo County. Motuo is the only county in China, which has no highway linking it to outside world. The exploitation of the waterway could be a solution to the problem. Two-thirds of the Yarlung Zangbo River's water resources, which ranks second only to the Yangtze River, are located in the canyon. A nature reserve should be set up first and then converted into a Grand Canyon State Park. The canyon has a very rich bio-diversity. It is home to over 60 per cent of the biological resources on the Qinghai-Tibet Plateau. The area's unique geological and environmental conditions, as well as its abundant natural resources, have long attracted the interest of Chinese and foreign scientists. The canyon, with its climatic advantages and tropical and subtropical bio-resources, will be a "museum" of species and a gene "storehouse." However, the core of the canyon is still a depopulated zone. No one has ever gone through it on foot and no one has ridden its turbulent current.

It includes the Great Turn V alley, where the Yarlung Zangbo River makes a 180-degree turn. The Medog Nature Reserve was set up there in 1986. Many scientists visited the reserve, but no one has ever hiked the length of the canyon. The word Medog means flower in Tibetan language. It is located 400 kilometres southeast to Lhasa. It is the only county in Tibet without road links

to the outside world. The reserve, which has an elevation of 600 metres and covers 626.2 square kilometres, making it a complete natural ecological environment, is famous as the site of the northern most tropical forests in China. The reserve is home to about 4,000 species of plants, accounting for half of the plant species in Tibet and 1 per cent of those in the world. So far,

21 very rare species have been discovered there. Rugged terrain and frequent landslides make it impossible for a road to remain open all the year round. A team of 40-odd Chinese scientists and journalists set off on October 19, 1998

to conquer the Yarlung Zangbo Grand Canyon. The scientists on the trek were from such fields as atmospheric science, botany, zoology, geography and environmental science Rebecca Lee Lok-si, an explorer from Hong Kong and vice-chairman of the China Association of Scientific Expeditions, took part. The team sent 20 people on a walk through the canyon in April 1998 , and this was good preparation for the large-scale expedition.

The Yarlung Zangbo River originates 5,590 metres above sea level in Gyemayangzong on China's Qinghai-Tibet Plateau. It flows into India as the Bramaputra River , and to Bangladesh as the Jamuna before emptying into the Indian Ocean. The Chinese section stretches 2,075 kilometres at the highest elevation of any river in the world. Some 75 per cent of the Chinese section flows through highlands at an average elevation of 3,000 metres. This section of the river also features the greatest drop in elevation of any river in the world, falling from 5,070 metres in the west to 155 metres in the east, a total drop of 4,915 metres. Man has never before entered various remote stretches in the river valley due to harsh weather conditions and geological features, which include rugged peaks, deep valleys and dangerous rapids. The rare geological and environmental conditions, as well as abundant natural resources in the area, have long attracted the interest of both Chinese and overseas scientists. The Yarlung Zangbo River has cut into the Qinghai-Tibet Plateau and formed a deep valley. It is the major passage for the southern air stream flowing towards the highlands in the north. Chinese scientists have determined that the source of the river is in the northern foothills of the Himalayas. Its upper stream is about 295 kilometres long. The riverbed is wide and shallow there _ The middle reaches are 1,361 kilometres in length, dropping from 4,550 metres to 2,800 metres above sea level. The middle reaches, which flow through areas of Tibetan culture and agriculture, include a number of famous tributaries, such as the Lhasa River. The lower reaches of the Yarlung Zangbo River make a sharp turn around Namjagbarwa Peak, emptying into astonishing gorge less than 100 metres wide. This dramatic gorge looks like a waterfall when viewed from the air. The river flows at a breath-taking rate of up to 84 kilometres per hour. The gorge, known as the Great Turn Valley, is listed in the Guinness Book of Records as the world's biggest and deepest valley. The valley starts at an elevation of 2,800 metres and ends at 500 metres, meaning the river in this section drops 2,300 metres. The valley is a great "library" of different species and is rich in bio-diversity. It is a natural reserve of rare species and living fossils. The gorge area is embraced by high peaks, which tower more than 5,000 metres above sea level. To the south, Mount Namjagbarwa is 7,782 metres high, and Gyarabaili to the north reaches 7,151 metres. Sheer cliffs drop from the peaks to the river. The Yarlung Zangbo River ranks second in China in terms of water resources, next only to the Yangtze River. Two-thirds of the Yarlung Zangbo's water resources are located in the gorge.