|青藏高原 (Qīng–Zàng Gāoyuán, Qinghai–Tibet Plateau)|
|Length||2,500 km (1,600 mi)|
|Width||1,000 km (620 mi)|
|Area||2,500,000 km2 (970,000 sq mi)|
|Location||China (Tibet, Qinghai, Western Sichuan, Northern Yunnan, Southern Xinjiang, Western Gansu)|
India (Ladakh, Lahaul & Spiti), Pakistan (Gilgit Baltistan)
Nepal (Northern Nepal)
Tajikistan (Eastern Tajikistan)
Kyrgyzstan (Southern Kyrgyzstan)
The Tibetan Plateau (Tibetan : བོད་ས་མཐོ།, Wylie : bod sa mtho), also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau (Chinese :青藏高原; pinyin :Qīng–Zàng Gāoyuán) or as the Himalayan Plateau in India, is a vast elevated plateau in South Asia, Central Asia and East Asia, covering most of the Tibet Autonomous Region, most of Qinghai, Northwestern Yunnan, Western half of Sichuan, Southern Gansu provinces in Western China, southern Xinjiang, the Indian regions of Ladakh and Lahaul and Spiti (Himachal Pradesh) as well as Gilgit-Baltistan in Pakistan, Bhutan, northern 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 is the world's highest and largest plateau above sea level, with an area of 2,500,000 square kilometres (970,000 sq mi) (about five times the size of Metropolitan France). 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 the headwaters of the drainage basins of most of the streams in surrounding regions. 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 the largest reserve of fresh water outside the polar regions. The impact of speculated climate change on the Tibetan Plateau is of ongoing scientific interest.
The Tibetan Plateau is surrounded by the massive mountain rangesof 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 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 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, 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 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 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 a result of this extremely inhospitable environment, the Changthang 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.
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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 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 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. The Indo-Australian plate continues to be driven horizontally below 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.[ citation needed ]
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 the low relief stems from erosion and infill of topographic depressions that occurred at already high elevations.
The current tectonics of the plateau is much debated. The two end-member models are the block model, in which the crust of the plateau is formed of several blocks with little internal deformation separated by major strike-slip faults. In the alternative continuum model, 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 the elevation and low precipitation. The Tibetan Plateau hosts the Tibetan wolf, 6,500 metres (21,300 ft).and species of snow leopard, wild yak, wild donkey, cranes, vultures, hawks, geese, snakes, and water buffalo. One notable animal is the high-altitude jumping spider, that can live at elevations of over
Ecoregions found on the Tibetan Plateau, as defined by the World Wide Fund for Nature, are as follows:
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 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, 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 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 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 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, 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, 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 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 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, 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 the Chinese lowlands.
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, though this opinion is now over a decade old:
Temperatures are rising four times faster than elsewhere in China, and the Tibetan glaciers are retreating at 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.
Nepal measures about 880 kilometers (547 mi) along its Himalayan axis by 150 to 250 kilometers across. It has an area of 147,516 km2 (56,956 sq mi).
China is a country located in East Asia with an area of 9,596,960 km2 (3,705,410 sq mi). The exact land area can sometimes be challenged by border disputes, including those concerning Taiwan, Aksai Chin, the Trans-Karakoram Tract, the South China Sea Islands, the Senkaku Islands, and South Tibet. As sovereignty over Hong Kong and Macau were restored to China in 1997 and 1999, two special administrative regions were established under the One Country, Two Systems policy. The People's Republic of China is either the third or fourth largest country in the world, being either slightly larger or slightly smaller than the United States depending on how the area of the United States is measured.
The Himalayas, or Himalaya, are a mountain range in Asia separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the highest, Mount Everest. Over 100 peaks exceeding 7,200 m (23,600 ft) in elevation lie in the Himalayas. By contrast, the highest peak outside Asia is 6,961 m (22,838 ft) tall.
The Tian Shan, also known as the Tengri Tagh or Tengir-Too, meaning the Mountains of Heaven or the Heavenly Mountain, is a large system of mountain ranges located in Central Asia. The highest peak in the Tian Shan is Jengish Chokusu, at 7,439 metres (24,406 ft) high. Its lowest point is the Turpan Depression, which is 154 m (505 ft) below sea level.
The Karakoram is a mountain range spanning the borders of China, India, and Pakistan, with the northwest extremity of the range extending to Afghanistan and Tajikistan. It begins in the Wakhan Corridor (Afghanistan) in the west, encompasses the majority of Gilgit-Baltistan, and extends into Ladakh and Aksai Chin. It is the second highest mountain range in the world and part of the complex of ranges including the Pamir Mountains, the Hindu Kush and the Himalayan Mountains. The Karakoram has eighteen summits over 7,500 m (24,600 ft) height, with four of them exceeding 8,000 m (26,000 ft): K2, the second highest peak in the world at 8,611 m (28,251 ft), Gasherbrum I, Broad Peak and Gasherbrum II.
The geography of Tibet consists of the high mountains, lakes and rivers lying between Central, East and South Asia. Traditionally, Western sources have regarded Tibet as being in Central Asia, though today's maps show a trend toward considering all of modern China, including Tibet, to be part of East Asia. Tibet is often called "the roof of the world," comprising tablelands averaging over 4,950 metres above the sea with peaks at 6,000 to 7,500 m, including Mount Everest, on the border with Nepal.
The Kunlun Mountains constitute one of the longest mountain chains in Asia, extending for more than 3,000 kilometres (1,900 mi). In the broadest sense, the chain forms the northern edge of the Tibetan Plateau south of the Tarim Basin.
Altyn-Tagh is a mountain range in Northwestern China that separates the Eastern Tarim Basin from the Tibetan Plateau. The western third is in Xinjiang while the eastern part forms the border between Qinghai to the south and Xinjiang and Gansu to the north.
The Qaidam, Tsaidam, or Chaidamu Basin is a hyperarid basin that occupies a large part of Haixi Prefecture in Qinghai Province, China. The basin covers an area of approximately 120,000 km2 (46,000 sq mi), one-fourth of which is covered by saline lakes and playas. Around one third of the basin, about 35,000 km2 (14,000 sq mi), is desert.
Matthias Kuhle was a German geographer and professor at the University of Göttingen. He edited the book series Geography International published by Shaker Verlag.
The Northeastern Himalayan subalpine conifer forests are a temperate coniferous forests ecoregion of the middle to upper elevations of the eastern Himalayas and southeast Tibetan Plateau. The ecoregion occurs in southeastern Tibet Autonomous Region, China, in northern and eastern Arunachal Pradesh, India, and extreme eastern Bhutan.
The ecology of the Himalayas varies with climate, rainfall, altitude, and soils. The climate ranges from tropical at the base of the mountains to permanent ice and snow at the highest elevations. The amount of yearly rainfall increases from west to east along the southern front of the range. This diversity of climate, altitude, rainfall and soil conditions supports a variety of distinct plant and animal species, such as the Nepal gray langur
Arunachal Pradesh is primarily a hilly tract nestled in the foothills of the Himalayas in northeast India. It is spread over an area of 83,743 km2 (32,333 sq mi). 98% of the geographical area is land out of which 80% is forest cover; 2% is water. River systems in the region, including those from the higher Himalayas and Patkoi and Arakan Ranges, eventually drain into the Brahmaputra River.
Altun Shan National Nature Reserve is a large, arid area in the southeast of Xinjiang Autonomous Region, on the northern edge of the Tibetan plateau and the southern edge of the Tarim Basin in northwest China. It surrounds the Kumkol Basin, an endorheic basin in the western third of the Altyn-Tagh mountains. The reserve is sometimes referred to as the "Arjin Mountains Nature Reserve", or "Aerjinshan". The reserve covers the southern portions of Qiemo County and Ruoqiang County of Bayingolin Mongol Autonomous Prefecture in Xinjiang.
High-Mountain Asia (HMA) is a high-elevation geographic region in Asia that includes numerous cordillera and highland systems around the Tibetan Plateau, encompassing regions of East, Southeast, Central and South Asia. The region was orogenically formed by the continental collision of the Indian Plate into the Eurasian Plate.
The Southeast Tibet shrub and meadows are a montane grassland ecoregion that cover the southeast and eastern parts of the Tibetan Plateau in China. The meadows in this region of Tibet are in the path of the monsoon rains and are wetter than the other upland areas of the Tibetan Plateau. The "high cold" alpine terrain is one of high species diversity, due to the relatively high levels of precipitation for the region. Precipitation is lower in the northwest, and hence the vegetation thins from shrub to meadow or even desert.
Kangri Karpo, also spelt Gangri Garbo, is a mountain range in eastern Tibet, located primarily in Nyingchi Prefecture as well as a portion of Qamdo Prefecture in the Tibet Autonomous Region, China. The mountain range lies to the east of the Himalayas and to the west of the Hengduan Mountains. The mountains are geographically a southern extension of the eastern Transhimalayas.
The paleogeography of the India–Asia collision system is the reconstructed geological and geomorphological evolution within the collision zone of the Himalayan orogenic belt. The continental collision between the Indian and Eurasian plate is one of the world's most renowned and most studied convergent systems. However, many mechanisms remain controversial. Some of the highly debated issues include the onset timing of continental collision, the time at which the Tibetan plateau reached its present elevation and how tectonic processes interacted with other geological mechanisms. These mechanisms are crucial for the understanding of Mesozoic and Cenezoic tectonic evolution, paleoclimate and paleontology, such as the interaction between the Himalayas orogenic growth and the Asian monsoon system, as well as the dispersal and speciation of fauna. Various hypotheses have been put forward to explain how the paleogeography of the collision system could have developed. Important ideas include the synchronous collision hypothesis, the Lhasa-plano hypothesis and the southward draining of major river systems.
The Qilian Mountains subalpine meadows ecoregion covers the high meadows and shrubland of the Qilian Mountains, on the northeastern edge of the Tibetan Plateau in central China. These mountains form a divide between the dry regions of the Gobi Desert to the north, and the Qaidam Basin and the Tibetan Plateau to the south. While the habitat supports populations of marmots, grouse and some rare mammal species, the grasslands of the region are under pressure from over-grazing by domestic livestock.
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