section_path: Geography
section_name: Geography
paragraph_text: Geography
  
  The Tibet Autonomous Region is located on the Tibetan Plateau, the highest region on Earth. In northern Tibet elevations reach an average of over 4,572 metres (15,000 ft). Mount Everest is located on Tibet's border with Nepal.
  
  China's provincial-level areas of Xinjiang, Qinghai and Sichuan lie to the north, northeast and east, respectively, of the Tibet AR. There is also a short border with Yunnan Province to the southeast. The countries to the south and southwest are Myanmar, India, Bhutan, and Nepal. China claims Arunachal Pradesh administered by India as part of the Tibet Autonomous Region. It also claims some areas adjoining the Chumbi Valley that are recognised as Bhutan's territory, and some areas of eastern Ladakh claimed by India. India and China agreed to respect the Line of Actual Control in a bilateral agreement signed on 7 September 1993.
  
  Physically, the Tibet AR may be divided into two parts: the lakes region in the west and north-west and the river region, which spreads out on three sides of the former on the east, south and west. Both regions receive limited amounts of rainfall as they lie in the rain shadow of the Himalayas; however, the region names are useful in contrasting their hydrological structures, and also in contrasting their different cultural uses: nomadic in the lake region and agricultural in the river region. On the south the Tibet AR is bounded by the Himalayas, and on the north by a broad mountain system. The system at no point narrows to a single range; generally there are three or four across its breadth. As a whole the system forms the watershed between rivers flowing to the Indian Ocean — the Indus, Brahmaputra and Salween and its tributaries — and the streams flowing into the undrained salt lakes to the north.
  
  The lake region extends from the Pangong Tso Lake in Ladakh, Lake Rakshastal, Yamdrok Lake and Lake Manasarovar near the source of the Indus River, to the sources of the Salween, the Mekong and the Yangtze. Other lakes include Dagze Co, Namtso, and Pagsum Co. The lake region is a wind-swept Alpine grassland. This region is called the Chang Tang (Byang sang) or 'Northern Plateau' by the people of Tibet. It is 1,100 km (680 mi) broad and covers an area about equal to that of France. Due to its great distance from the ocean it is extremely arid and possesses no river outlet. The mountain ranges are spread out, rounded, disconnected, and separated by relatively flat valleys.
  
  The Tibet AR is dotted over with large and small lakes, generally salt or alkaline, and intersected by streams. Due to the presence of discontinuous permafrost over the Chang Tang, the soil is boggy and covered with tussocks of grass, thus resembling the Siberian tundra. Salt and fresh-water lakes are intermingled. The lakes are generally without outlet, or have only a small effluent. The deposits consist of soda, potash, borax and common salt. The lake region is noted for a vast number of hot springs, which are widely distributed between the Himalaya and 34° N, but are most numerous to the west of Tengri Nor (north-west of Lhasa). So intense is the cold in this part of Tibet that these springs are sometimes represented by columns of ice, the nearly boiling water having frozen in the act of ejection.
  
  The river region is characterized by fertile mountain valleys and includes the Yarlung Tsangpo River (the upper courses of the Brahmaputra) and its major tributary, the Nyang River, the Salween, the Yangtze, the Mekong, and the Yellow River. The Yarlung Tsangpo Canyon, formed by a horseshoe bend in the river where it flows around Namcha Barwa, is the deepest and possibly longest canyon in the world. Among the mountains there are many narrow valleys. The valleys of Lhasa, Xigazê, Gyantse and the Brahmaputra are free from permafrost, covered with good soil and groves of trees, well irrigated, and richly cultivated.
  
  The South Tibet Valley is formed by the Yarlung Tsangpo River during its middle reaches, where it travels from west to east. The valley is approximately 1,200 km (750 mi) long and 300 km (190 mi) wide. The valley descends from 4,500 m (14,760 ft) above sea level to 2,800 m (9,190 ft). The mountains on either side of the valley are usually around 5,000 m (16,400 ft) high. Lakes here include Lake Paiku and Lake Puma Yumco.