Qinghai Lake

Description

Qinghai Lake or Ch’inghai Lake, also known by other names, is the largest lake in China. Located in an endorheic basin in Qinghai Province, to which it gave its name, Qinghai Lake is classified as an alkaline salt lake. The lake has fluctuated in size, shrinking over much of the 20th century but increasing since 2004. It had a surface area of 4,317 km2 (1,667 sq mi), an average depth of 21 m (69 ft), and a maximum depth of 25.5 m (84 ft) in 2008. Qinghai Lake lies about 100 kilometers (62 mi) west of Xining in a hollow of the Tibetan Plateau at 3,205 meters (10,515 ft) above sea level. It lies between Haibei Tibetan Autonomous Prefecture and Hainan Tibetan Autonomous Prefecture in northeastern Qinghai in Northwest China. The lake has fluctuated in size, shrinking over much of the 20th century but increasing since 2004. It had a surface area of 4,317 square kilometers (1,667 sq mi), an average depth of 21 meters (69 ft), and a maximum depth of 25.5 m (84 ft) in 2008. Twenty-three rivers and streams empty into Qinghai Lake, most of them seasonal. Five permanent streams provide 80% of the total influx. The relatively low inflow and high evaporation rates have turned Qinghai saline and alkaline; it is presently about 14 ppt salt with a pH of 9.3. It has increased in salinity and basicity since the early Holocene. At the tip of the peninsula on the western side of the lake are Cormorant Island and Egg Island, collectively known as the Bird Islands. Wildlife The lake is located at the crossroads of several bird migration routes across Asia. Many species use Qinghai as an intermediate stop during migration. As such, it is a focal point in global concerns regarding avian influenza (H5N1), as a major outbreak here could spread the virus across Europe and Asia, further increasing the chances of a pandemic. Minor outbreaks of H5N1 have already been identified at the lake. The Bird Islands have been sanctuaries of the Qinghai Lake Natural Protection Zone since 1997. There are five native fish species: The edible naked carp (Gymnocypris przewalskii), which is the most abundant in the lake, and four stoneloaches (Triplophysa stolickai, T. dorsonotata, T. scleroptera and T. siluroides). Other Yellow River fish species occurred in the lake, but they disappeared with the increasing salinity and basicity, beginning in the early Holocene.