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Yarlung Valley

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Samding Dorje Phagmo

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47-850: The Yarlung Valley is formed by Yarlung Chu, a tributary of the Tsangpo River in the Shannan Prefecture in the Tibet autonomous region of China. It refers especially to the district where Yarlung Chu joins with the Chongye River, and broadens out into a large plain about 2 km wide, before it flows into the Tsangpo River. It is situated in Nedong District of the Shannan Prefecture and includes

94-542: A higher speed than in any other part of the world. In the short term, this will cause lakes to expand and bring floods and mudflows. In the long run, the glaciers are vital lifelines for Asian rivers, including the Indus and the Ganges . Once they vanish, water supplies in those regions will be in peril. The Tibetan Plateau contains the largest area of low- latitude glaciers and is particularly vulnerable to global warming. Over

141-699: A result of this extremely inhospitable environment, the Changtang region (together with the adjoining Kekexili region) is the least populous region in Asia and the third least populous area in the world after Antarctica and northern Greenland. The geological history of the Tibetan Plateau is closely related to that of the Himalayas. The Himalayas belong to the Alpine Orogeny and are therefore among

188-415: A steady wind to blow toward the land, which brings the moist air over the ocean surface with it. Rainfall is then increased by the presence of the moist ocean air. The rainfall is stimulated by a variety of mechanisms, such as low-level air being lifted upwards by mountains, surface heating, convergence at the surface, divergence aloft, or from storm-produced outflows near the surface. When such lifting occurs,

235-635: A term usually referring to the localized, diurnal cycle of circulation near coastlines everywhere, but they are much larger in scale, stronger and seasonal. The seasonal monsoon wind shift and weather associated with the heating and cooling of the Tibetan plateau is the strongest such monsoon on Earth. Today, Tibet is an important heating surface of the atmosphere. However, during the Last Glacial Maximum , an approximately 2,400,000 square kilometres (930,000 sq mi) ice sheet covered

282-629: Is approximately at 3,200 metres (10,500 ft). Sedimentary sandstone rocks found near the Tibetan capital of Lhasa contain grains of magnetic minerals that record the Earth's alternating magnetic field current. The basin of the Yarlung River, bounded by the Himalayas in the south and Kang Rinpoche and Nyenchen Tanglha Mountains in the north, has less severe climate than the adjacent northern (and higher-altitude) parts of Tibet, and

329-587: Is called the Padma . When leaving the Tibetan Plateau , the river forms the world's largest and deepest canyon, Yarlung Tsangpo Grand Canyon . The Yarlung Tsangpo River is the highest major river in the world. Its longest tributary is the Nyang River . Major tributaries of Yarlung Tsangpo include Nyangchu River, Lhasa River , Nyang River , and Parlung Tsangpo . In Tibet the river flows through

376-662: Is called the Siang. After reaching Assam , the river is known as the Brahmaputra . From Assam, the river enters Bangladesh at Ramnabazar. From there until about 200 years ago it used to flow eastward and joined the Meghna River near Bhairab Upazila . This old channel has been gradually dying. At present the main channel of the river is called Jamuna River , which flows southward to meet the Ganges , which in Bangladesh

423-409: Is distributed vertically through a "mixed layer" that may be 50 meters deep through the action of wind and buoyancy-generated turbulence , whereas the land surface conducts heat slowly, with the seasonal signal penetrating only a meter or so. Additionally, the specific heat capacity of liquid water is significantly greater than that of most materials that make up land. Together, these factors mean that

470-483: Is home to most of the population of the Tibetan Autonomous Region . The Yarlung Tsangpo Grand Canyon , formed by a horse-shoe bend in the river where it leaves the Tibetan Plateau and flows around Namcha Barwa , is the deepest, and possibly longest canyon in the world. The Yarlung Tsangpo River has three major waterfalls in its course. The largest waterfall of the river, the "Hidden Falls",

517-880: Is located to the north of Himalayas and the Indian subcontinent , and to the south of Tarim Basin and Mongolian Plateau . Geopolitically, it covers most of the Tibet Autonomous Region , most of Qinghai , western half of Sichuan , Southern Gansu provinces in Western China , southern Xinjiang , Bhutan , the Indian regions of Ladakh and Lahaul and Spiti ( Himachal Pradesh ) as well as Gilgit-Baltistan in Pakistan , northwestern Nepal , eastern Tajikistan and southern Kyrgyzstan . It stretches approximately 1,000 kilometres (620 mi) north to south and 2,500 kilometres (1,600 mi) east to west. It

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564-804: Is the Qilian Mountains. The line of mountains continues east of the plateau as the Qinling , which separates the Ordos Plateau from Sichuan. North of the mountains runs the Gansu or Hexi Corridor which was the main silk-road route from China proper to the West. The plateau is a high-altitude arid steppe interspersed with mountain ranges and large brackish lakes. Annual precipitation ranges from 100 to 300 millimetres (3.9 to 11.8 in) and falls mainly as hail . The southern and eastern edges of

611-527: Is the world's highest and largest plateau above sea level, with an area of 2,500,000 square kilometres (970,000 sq mi). With an average elevation exceeding 4,500 metres (14,800 ft) and being surrounded by imposing mountain ranges that harbor the world's two highest summits, Mount Everest and K2 , the Tibetan Plateau is often referred to as "the Roof of the World ". The Tibetan Plateau contains

658-561: The Changtang , is generally too high and cold to support permanent population. One of the most notable civilizations to have developed on the Tibetan Plateau is the Tibetan Empire from the 7th century to the 9th century AD. Monsoons are caused by the different amplitudes of surface temperature seasonal cycles between land and oceans. This differential warming occurs because heating rates differ between land and water. Ocean heating

705-538: The Eurasian Plate . About 50 million years ago, this fast-moving Indo-Australian plate had completely closed the Tethys Ocean , the existence of which has been determined by sedimentary rocks settled on the ocean floor, and the volcanoes that fringed its edges. Since these sediments were light, they crumpled into mountain ranges rather than sinking to the floor. During this early stage of its formation in

752-971: The Kunlun Mountains separate the plateau from the Tarim Basin. About halfway across the Tarim the bounding range becomes the Altyn-Tagh and the Kunluns, by convention, continue somewhat to the south. In the 'V' formed by this split is the western part of the Qaidam Basin . The Altyn-Tagh ends near the Dangjin pass on the Dunhuang – Golmud road. To the west are short ranges called the Danghe, Yema, Shule, and Tulai Nanshans. The easternmost range

799-791: The Yarlung dynasty of Tibetan kings and controlled important ancient trade routes into India and Bhutan . The first Tibetan Emperor, Songtsen Gampo (605 or 617? - 649), moved the capital to Lhasa after greatly expanding his territories and power. The valley, often referred to as the "cradle of Tibetan civilisation", is only 72 km (45 mi) long, but contains a number of important castles, monasteries, temples, meditation caves, peaks and stupas . There are three renowned power places ( ne-sum ), Sheldrak, Tradruk , and Yumbu Lagang or ( Yungbulakang Palace ). Also, there are three major stupas which serve as receptacles for sacred relics ( ten-sum ): Takchen Bumpa, Gontang Bumpa, and Tsechu Bumpa. Just below

846-577: The headwaters of the drainage basins of most of the streams and rivers in surrounding regions . This includes the three longest rivers in Asia (the Yellow , Yangtze , and Mekong ). Its tens of thousands of glaciers and other geographical and ecological features serve as a " water tower " storing water and maintaining flow . It is sometimes termed the Third Pole because its ice fields contain

893-696: The thermal low pressure caused by the heating, there was no monsoon over the Indian subcontinent . This lack of monsoon caused extensive rainfall over the Sahara , expansion of the Thar Desert , more dust deposited into the Arabian Sea , and a lowering of the biotic life zones on the Indian subcontinent. Animals responded to this shift in climate, with the Javan rusa migrating into India. In addition,

940-652: The Chinese lowlands. Ice of the plateau provides a valuable window to the past. In 2015, researchers studying the Plateau reached the top of the Guliya glacier , with ice thickness of 310 m (1,020 ft), and drilled to a depth of 50 m (160 ft) in order to recover ice core samples. Due to the extremely low biomass in those 15,000-year-old samples, it had taken around 5 years of research to extract 33 viruses, of which 28 were new to science. None had survived

987-893: The Late Palaeogene, Tibet consisted of a deep palaeovalley bounded by multiple mountain ranges rather than the more topographically uniform elevated flatland that it is today. The Tibetan Plateau's mean elevation continued to vary since its initial uplift in the Eocene; isotopic records show the plateau's altitude was around 3,000 metres above sea level around the Oligocene-Miocene boundary and that it fell by 900 metres between 25.5 and 21.6 million years ago, attributable to tectonic unroofing from east–west extension or to erosion from climatic weathering. The plateau subsequently rose by 500 to 1,000 metres between 21.6 and 20.4 million years ago. Palaeobotanical evidence indicates that

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1034-767: The Nujiang Suture Zone and the Yarlung-Zangpo Suture Zone remained tropical or subtropical lowlands until the latest Oligocene or Early Miocene , enabling biotic interchange across Tibet. The age of east–west grabens in the Lhasa and Himalaya terranes suggests that the plateau's elevation was close to its modern altitude by around 14 to 8 million years ago. Erosion rates in Tibet decreased significantly around 10 million years ago. The Indo-Australian plate continues to be driven horizontally below

1081-465: The River in a large boat containing traders and their donkeys. Tsangpo river The Yarlung Tsangpo , also called Yarlung Zangbo ( Tibetan : ཡར་ཀླུངས་གཙང་པོ་ , Wylie : yar kLungs gTsang po , ZYPY : Yarlung Zangbo ) and Yalu Zangbu River ( Chinese : 雅鲁藏布江 ; pinyin : Yǎlǔzàngbù Jiāng ) is located in the Tibet Autonomous Region , China . It is the longest river of Tibet and

1128-493: The South Tibet Valley, which is approximately 1,200 kilometres (750 mi) long and 300 kilometres (190 mi) wide. The valley descends from 4,500 metres (14,800 ft) above sea level to 3,000 metres (9,800 ft). As it descends, the surrounding vegetation changes from cold desert to arid steppe to deciduous scrub vegetation. It ultimately changes into conifer and rhododendron forest. The tree line

1175-428: The Tibetan Plateau, which forces the plateau to move upwards; the plateau is still rising at a rate of approximately 5 mm (0.2 in) per year (although erosion reduces the actual increase in height). Much of the Tibetan Plateau is of relatively low relief. The cause of this is debated among geologists. Some argue that the Tibetan Plateau is an uplifted peneplain formed at low altitude, while others argue that

1222-476: The Tibetan plateau from around 200,000 to 40,000 years ago, according to a study published in Nature . Nomads on the Tibetan Plateau and in the Himalayas are the remainders of nomadic practices historically once widespread in Asia and Africa. Pastoral nomads constitute about 40% of the ethnic Tibetan population. The presence of nomadic peoples on the plateau is predicated on their adaptation to survival on

1269-433: The air cools due to expansion in lower pressure, which in turn produces condensation and precipitation. In winter, the land cools off quickly, but the ocean maintains the heat longer. The hot air over the ocean rises, creating a low-pressure area and a breeze from land to ocean while a large area of drying high pressure is formed over the land, increased by wintertime cooling. Monsoons are similar to sea and land breezes ,

1316-402: The capital of the prefecture, Tsetang , one of Tibet's largest cities, 183 km southeast of Lhasa . 29°12′N 91°46′E  /  29.200°N 91.767°E  / 29.200; 91.767 It was originally well-forested and suitable for agriculture. The Tsetang district is famous for its apples and pears. The Yarlung and the adjoining Chongye Valley formed the original seat of

1363-593: The elevation and low precipitation. The Tibetan Plateau hosts the Tibetan wolf , and species of snow leopard , wild yak , wild ass , cranes, vultures, hawks, geese, snakes, and water buffalo . One notable animal is the high-altitude jumping spider , that can live at elevations of over 6,500 metres (21,300 ft). Ecoregions found on the Tibetan Plateau, as defined by the World Wide Fund for Nature , are as follows: Extinct humans ( Denisovans ) lived on

1410-605: The extraction process. Phylogenetic analysis suggests those viruses infected plants or other microorganisms. The Tibetan Plateau contains the world's third-largest store of ice. Qin Dahe, the former head of the China Meteorological Administration , issued the following assessment in 2009: Temperatures are rising four times faster than elsewhere in China, and the Tibetan glaciers are retreating at

1457-412: The fifth longest in China. The upper section is also called Dangque Zangbu meaning "Horse River." Originating at Angsi Glacier in western Tibet, southeast of Mount Kailash and Lake Manasarovar , it later forms the South Tibet Valley and Yarlung Tsangpo Grand Canyon before passing into the state of Arunachal Pradesh , India . Downstream from Arunachal Pradesh, the river becomes far wider and

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1504-530: The first descent of the upper Tsangpo gorge section. In November 2020, the chairman of PowerChina announced the construction of a "super" dam on the Yarlung Zangbo which would be the world's largest hydroelectric project. Tibetan Plateau The Tibetan Plateau , also known as Qinghai–Tibet Plateau and Qing–Zang Plateau , is a vast elevated plateau located at the intersection of Central , South , and East Asia . . Geographically, it

1551-541: The glaciers in Tibet created meltwater lakes in the Qaidam Basin , the Tarim Basin , and the Gobi Desert , despite the strong evaporation caused by the low latitude. Silt and clay from the glaciers accumulated in these lakes; when the lakes dried at the end of the ice age, the silt and clay were blown by the downslope wind off the Plateau. These airborne fine grains produced the enormous amount of loess in

1598-496: The gorge from 1973 on, had already taken pictures of the falls in 1987 from a helicopter. Since the 1990s the Yarlung Tsangpo River has been the destination of a number of teams that engage in exploration and whitewater kayaking . The river has been called the "Everest of Rivers" because of the extreme conditions of the river. The first attempt to run was made in 1993 by a Japanese group who lost one member on

1645-400: The heat capacity of the layer participating in the seasonal cycle is much larger over the oceans than over land, with the consequence that the land warms and cools faster than the ocean. In turn, air over the land warms faster and reaches a higher temperature than does air over the ocean. The warmer air over land tends to rise, creating an area of low pressure . The pressure anomaly then causes

1692-405: The largest reserve of fresh water outside the polar regions. The impact of climate change on the Tibetan Plateau is of ongoing scientific interest. The Tibetan Plateau is surrounded by the massive mountain ranges of high-mountain Asia . The plateau is bordered to the south by the inner Himalayan range , to the north by the Kunlun Mountains , which separate it from the Tarim Basin , and to

1739-404: The latter, the plateau is affected by distributed deformation resulting from flow within the crust. The Tibetan Plateau supports a variety of ecosystems, most of them classified as montane grasslands. While parts of the plateau feature an alpine tundra -like environment, other areas feature monsoon-influenced shrublands and forests. Species diversity is generally reduced on the plateau due to

1786-428: The low relief stems from erosion and infill of topographic depressions that occurred at already high elevations. The current tectonics of the plateau are also debated. The best-regarded explanations are provided by the block model and the alternative continuum model. According to the former, the crust of the plateau is formed of several blocks with little internal deformation separated by major strike-slip faults . In

1833-688: The northeast by the Qilian Mountains , which separate the plateau from the Hexi Corridor and Gobi Desert . To the east and southeast the plateau gives way to the forested gorge and ridge geography of the mountainous headwaters of the Salween , Mekong , and Yangtze rivers in northwest Yunnan and western Sichuan (the Hengduan Mountains ). In the west, the curve of the rugged Karakoram range of northern Kashmir embraces

1880-513: The plateau. Due to its great extent, this glaciation in the subtropics was an important element of radiative forcing . With a much lower latitude, the ice in Tibet reflected at least four times more radiation energy per unit area into space than ice at higher latitudes . Thus, while the modern plateau heats the overlying atmosphere, during the Last Ice Age it helped to cool it. This cooling had multiple effects on regional climate. Without

1927-406: The plateau. The Indus River originates in the western Tibetan Plateau in the vicinity of Lake Manasarovar . The Tibetan Plateau is bounded in the north by a broad escarpment where the altitude drops from around 5,000 metres (16,000 ft) to 1,500 metres (4,900 ft) over a horizontal distance of less than 150 kilometres (93 mi). Along the escarpment is a range of mountains. In the west,

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1974-673: The river. In October 1998, a kayaking expedition sponsored by the National Geographic Society attempted to navigate the Yarlung Tsangpo Grand Canyon . Troubled by unanticipated high water levels, the expedition ended in tragedy with the death of expert kayaker Doug Gordon . In January–February 2002, an international group consisting of Scott Lindgren, Steve Fisher, Mike Abbott, Allan Ellard, Dustin Knapp, and Johnnie and Willie Kern, completed

2021-511: The steppe have grasslands that can sustainably support populations of nomadic herdsmen, although frost occurs for six months of the year. Permafrost occurs over extensive parts of the plateau. Proceeding to the north and northwest, the plateau becomes progressively higher, colder, and drier, until reaching the remote Changtang region in the northwestern part of the plateau. Here the average altitude exceeds 5,000 metres (16,000 ft) and winter temperatures can drop to −40 °C (−40 °F). As

2068-504: The town of Tsetang there once was a 14th-century iron suspension bridge built across the Yarlung Tsangpo River or Brahmaputra by the famous engineer Tangtong Gyalpo , with a span of 150 to 250 metres, but only five large stone supports are left today. A modern bridge has been built a few kilometres downstream at Nyago. Even when Sarat Das visited in 1879 it was in such a state of disrepair that he had to ferry across

2115-400: The world's grassland by raising livestock rather than crops, which are unsuitable to the terrain. Archaeological evidence suggests that the earliest human occupation of the plateau occurred between 30,000 and 40,000 years ago. Since colonization of the Tibetan Plateau, Tibetan culture has adapted and flourished in the western, southern, and eastern regions of the plateau. The northern portion,

2162-605: The younger mountain ranges on the planet, consisting mostly of uplifted sedimentary and metamorphic rock . Their formation is a result of a continental collision or orogeny along the convergent boundary between the Indo-Australian Plate and the Eurasian Plate . The collision began in the Upper Cretaceous period about 70 million years ago, when the north-moving Indo-Australian Plate , moving at about 15 cm (6 in) per year, collided with

2209-434: Was not publicized in the West until 1998, when its sighting by Westerners was briefly hailed as a "discovery." They were even portrayed as the discovery of the great falls which had been the topic of stories told to early westerners by Tibetan hunters and Buddhist monks , but which had never been found by Western explorers at the time. The Chinese authorities contradicted, however, saying that Chinese geographers, who explored

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