The Qarhan Playa covers an area of , stretching over east to west and usually between north to south. The southwest lies in
Golmud and the northeast in
Dulan County, both in
Haixi Prefecture,
Qinghai,
China. The roughly area of Qarhan inclusive of
Taijinar to its west is sometimes known as the Sanhu ("Three Lakes"), after the two Taijinar lakes,
Suli Lake, and
Dabusun. Qarhan is part of the larger
Qaidam Basin, lying between the
Kunlun Mountains to the south, the
Altun to the west, and the
Qilian to the north. Qarhan's lakes lie between above
sea level, with Dabusun and North Hulsan being the lowest and Xiezuo being the highest. The effect of elevation is such that despite lying on the
same latitude as
Greece,
Algeria, and
Virginia in the
United States, Qarhan has a mean annual temperature of . The mean air speed is , and the mean
relative humidity is 27.7%. In the playa's hyperarid climate, there is generally only of annual rainfall but of annual evaporation. Despite this,
meltwater rivers and
mineral springs fill the basins of the salt flat's four main sectionsBieletan, Dabusun, Qarhan, and Huoluxunwith about ten large but shallow lakes usually collectively occupying an area of about :
Suli Lake in the west, fed from the west by the
Urt Moron; the
Little and
Big Biele Lakes beside it, fed from the south by the
Tuolahai and
Qingshui Rivers;
West Dabusun and
Dabusun Lake (the largest), in the center, fed from the south by the
Golmud River;
Dongling Lake to their northwest;
Xiezuo and
Tuanjie Lakes to their east, fed respectively by the intermittent
Quanji and
Shougong Rivers; and
North and
South Hulsan Lakes at the east end of the playa, fed from the east by the
Qaidam,
Nuomuhong, and
Suolinguole Rivers. All of these are usually less than deep. There are also some
ephemeral lakes. Most of the streams contributing to these lakes flow north into the playa from the Kunlun and its foothills. The Golmud River is the main contributor, providing a mean annual influx of 19.2 trillion L (5.07 trillion gal) of water. There is also contribution of about 1% from
mineral springs, especially on the north end of the playa, which play an important role in the chemical composition of the sediment. The local
flora consists of sparse
forbs (particularly members of
Chenopodioideae) and
shrubs, especially members of
Ephedra and
Tamarix. ==Geology==