Qaidam Basin

Qaidam Basin, also spelled Tsaidam (from Mongolian: Цайдам, "salt marsh" or "wide valley"; simplified Chinese: 柴达木盆地; traditional Chinese: 柴達木盆地; pinyin: Cháidámù Péndì) is an hyperarid basin that occupies a large part of the Haixi Mongol and Tibetan Autonomous Prefecture in Qinghai Province, western China. The basin covers an area of approximately 120,000 km2, one fourth of which is covered by saline lakes and playas.

Around 35,000 square kilometers, or one third of the basin is desert, which is known in Chinese as Chaidamu Pendi Shamo (柴达木盆地沙漠), i.e. Qaidam Basin Desert.

The Qaidam Basin forms a sort of shelf on the northeast side of the Tibetan Plateau. The Tibetan Plateau is at least 14,000 feet above sea level, the Qaidam about 10,000 and Gansu to the north about 3,000 to 4,000 feet. A low water divide separates the Qaidam Basin proper from that of Qinghai Lake to the east.

Orographically, the Qaidam Basin is a comparatively low areas in the northeastern part of the Tibetan Plateau. Qaidam is an intermontane basin, i.e. it is surrounded on all sides by mountain ranges. In the south, the Kunlun Mountains separate it from the higher central section of the Tibetan Plateau. In the north, a number of smaller ridges (Shulenanshan, etc.) separate the basin from another higher plateau, which is more known for its northern escarpment, the Qilian Mountains; that entire mountain system is often generically known as Nanshan. In the northwest, the Altyn-Tagh separates the Qaidam Basin from the Kumtagh Desert of southeastern Xinjiang.