Qiangtang

▪ basin, China

Wade-Giles romanization  Ch'iang-t'ang,  Tibetan  Byang Thang 

      enormous alpine basin in the northern part of the Tibet Autonomous Region, southwestern China. With an average elevation exceeding 16,500 feet (5,000 metres) above sea level, it lies between the Kunlun Mountains to the north, the Tanggula Mountains to the east, and the Nyainqêntanglha Mountains to the south and stretches some 800 miles (1,300 km) from the mountain complex called the Pamirs in the west to the region of the Qaidam Basin in the northeast. At its widest it is almost 300 miles (480 km) from north to south. The Qiangtang is a series of slightly undulating plains separated by ranges of hills. The surface is stony and rocky, with great accumulations of friable rock, broken up by frost weathering in the intensely cold climate occurring at such high elevations. A large part of the basin is a sterile expanse of rock and gravel. There are no perennial rivers, but great numbers of salt lakes represent the remnants of bodies of water that were once much larger. Where those have dried up in the arid climate—the area receives less than 4 inches (100 mm) of precipitation annually and experiences high evaporation rates because of the constant winds—huge deposits of salt have formed.

      The climate is as inhospitable as the landscape. Summer lasts only three months, and temperatures in July average only 50 °F (10 °C); even in summer the night temperature often drops below freezing. In the winter the temperatures frequently fall below −31 °F (−35 °C); the area is constantly blasted by high winds, and the snow never settles. All the lakes and watercourses freeze solid. The area is at its bleakest in the north, most of which either is sterile rocky desert or has a sparse cover of hardy grasses. The southern section is somewhat less dry and has a denser grass covering, with a few shrubs and hardy juniper trees growing around Lake Nam, the largest of the lakes. The mountain areas within the Qiangtang are permanently covered with snow and ice at elevations above about 19,000 feet (5,800 metres). The whole area is unsuitable for permanent settlement. Its only population, consisting of nomadic herders, is found in the south.

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