CH'IANG-T'ANG

Pinyin Qiangtang, Tibetan Byang Thang enormous alpine basin in the northern part of the Tibetan autonomous ch' (region), China. With an average elevation of more than 16,500 feet (5,000 m) above sea level, it lies between the Kunlun Mountains to the north and the T'ang-ku-la Mountains and A-ling Mountains to the south and stretches 800 miles (1,300 km) from the mountain complex called the Pamir Knot in the west to the region of the Tsaidam Basin in the northeast. At its widest it is almost 300 miles (480 km) from north to south. The Ch'iang-t'ang 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 altitudes. 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 these have dried up in the arid climate-the area receives less than 4 inches (100 mm) of rain 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); snow never settles, and the area is blasted by constant high winds. All the lakes and watercourses freeze solid. The area is at its most bleak 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 much more continuous grass covering, with a few shrubs and hardy juniper trees growing around Na-mu-ts'o, the largest of the lakes. The mountain areas within the Ch'iang-t'ang are permanently covered with snow and ice at elevations above about 19,000 feet (5,800 m). The whole area is unsuitable for permanent settlement. Its only population, consisting of nomadic herders, is found in the south.