Tibetan Plateau
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The Tibetan Plateau or Chang Tang, also known as the Qinghai-Tibetan (Qingzang) Plateau, is a vast, elevated plateau in East Asia covering most of the Tibet Autonomous Region and Qinghai Province in China. It occupies an area of around 1,000 by 2,500 kilometers, and has an average elevation of over 4,500 meters. Called "the roof of the world," it is the highest and biggest plateau in the world, with an area of 2.5 million square kilometers (about four times the size of Texas or France) [1]. The plateau was formed by the collision of the Indo-Australian and Eurasian tectonic plates in the Cenozoic period (approximately 55 million years ago), in a process that is still ongoing.
The plateau is a high-altitude arid steppe interspersed with mountain ranges and large brackish lakes. Annual precipitation ranges from 100mm to 300mm and falls mainly as hailstorms. [2] The southern and eastern edges of the steppe have grasslands which can sustainably support populations of nomadic herdsmen, although frost occurs for six months of the year. Proceeding to the north and northwest, the plateau becomes progressively higher, colder and drier, until reaching the remote Kekexili region in the northwestern part of the plateau. Here the average altitude exceeds 5,000 meters (16,500 feet), the air contains only 60% of the oxygen of sea level, and year-round temperatures average -4°C, dipping to -40°C in winter. [3] As a result of this extremely inhospitable environment, the Kekexili region is the least populated region in Asia, and the third least populated area in the world after Antarctica and northern Greenland.
The Chang Tang is bordered to the northwest by the Kunlun Range which separate it from the Tarim Basin, and to the northeast by the Qilian Range which separates the plateau from the Gobi Desert. In the south the plateau is delineated by the Brahmaputra river valley which flows along the base of the Himalayas, and by the vast Indo-Gangetic Plain. To the east and southeast the plateau gives way to the forested gorge and ridge geography of the mountain headwaters of the Salween, Mekong, and Yangtze rivers in western Sichuan. In the west it is embraced by the curve of the rugged Karakoram range of northern Kashmir.
The tectonic uplift of the plateau is thought to have had a significant effect on climate change, and it is believed to affect the Asian monsoon. In the Indian monsoon season (June to October) when the winds bring humid, tropical air from the south, the Himalayas create a rain shadow which makes northern India very wet and keeps the Tibetan Plateau very dry. As the winds continue over the plateau, they drop what little moisture remains in the air, becoming drier as they move northwards and creating deserts such as the Taklamakan and the Gobi Desert.
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[edit] Rivers
Several of the world's longest rivers originate on the Tibetan Plateau:
- Yangtze River (or Chang Jiang)
- Huang He (or Yellow River)
- Indus River
- Satluj River
- Brahmaputra, known as the Yarlung Tsangpo in Tibet
- Mekong
- Irrawaddy River
- Salween River
Between them, these rivers carry 25% of the world's soil erosion to the sea.
[edit] Lakes
[edit] Reference
[edit] See also
[edit] External links
- www.PlateauPerspectives.org
- Leaf morphology and the timing of the rise of the Tibetan Plateau
- todays weather in the eastern Chang Tang
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