The Tibetan Plateau,[a] also known as the Qinghai–Tibet Plateau[b] or Qingzang Plateau,[c] is a vast
elevated plateau located at the intersection of Central, South, and East Asia.[d] Geographically, it 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, southern Xinjiang province
in Western China, 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 is the world's highest and largest plateau above sea level, with an area of 2,500,000 square
kilometres (970,000 sq mi).[13] With an average elevation exceeding 4,500 metres (14,800 ft)[citation
needed]
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".[14]
The Tibetan Plateau contains 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 the largest reserve of fresh water outside the
polar regions. The impact of climate change on the Tibetan Plateau is of ongoing scientific
interest.[15][16][17][18]
The Tibetan Plateau is surrounded by the massive mountain ranges[19] 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 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 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.
