Qaidam Desert

Modern English scientific literature normally calls the physical depression the Qaidam Basin. The Library of Congress heading retains Tsaidam Basin (China) and records Qaidam Basin, Chaidamu Pendi, Tsadam, Tsaydam and Zaidam as variants.^[1] This page keeps the familiar atlas title “Qaidam Desert,” but its exact subject is the desert landforms on the basin floor—not Haixi Prefecture, the surrounding mountain catchment or every surface inside the 120,000 km² basin.

No authoritative polygon found in the reviewed sources isolates a single Qaidam Desert perimeter. Sand, yardangs, saline flats, lakes, river corridors and alluvial fans interlock, and different studies map different process-defined surfaces. The basin area therefore supplies the geographic frame; the 34,163 km² aeolian inventory is the more specific measure of dune and wind-eroded terrain.^[2][3]

Qaidam lies wholly in western China, mainly within Haixi Mongol and Tibetan Autonomous Prefecture in Qinghai. The Altyn-Tagh bounds the northwest, the Qilian orogenic belt the north and northeast, and the Eastern Kunlun–Qiman Tagh belt the south and southwest.^[2] The basin floor averages about 2,800 m above sea level, yet it is a topographic low relative to 4,000–5,000 m ranges around it.

The published 35°00′–39°20′ N, 90°16′–99°16′ E envelope describes the whole research frame. Within it, the western and central lowlands carry the most extensive yardang and playa terrain; the central-eastern lowland contains the Qarhan salt-lake complex; and coalescing fans rise from the Eastern Kunlun and Qilian fronts.

Qaidam is a tectonic depression, not an impact crater or a simple hollow eroded into the plateau. Seismic-reflection profiles show a broad Cenozoic synclinorium—a regional downfold containing smaller folds—with structural amplitude greater than 16 km in the west and less than 4 km in the east. Northern basin-margin deformation began about 65–50 million years ago; major southern-margin deformation followed about 29–24 million years ago.^[4]

Weathering and erosion of the surrounding ranges filled that deforming basin with alluvial, river, lake and wind-blown sediment. Published syntheses report as much as about 12 km of Cenozoic fill in places, while folds and faults divide the western basin into local subbasins.^[2] At the surface, coarse gravel fans and piedmont aprons grade inward to finer lake sediment, clay-rich playa ground and evaporite crusts.

A yardang is a streamlined ridge cut by wind from relatively soft, exposed sediment or rock. Qaidam's yardangs are concentrated mainly in the northwestern and central-eastern basin. Their orientations differ between fields, and their shapes reflect not only wind but also bedding direction, rock resistance, water erosion, salt weathering and slope failure.^[2]

Dunes occupy a smaller mapped area than wind-eroded terrain. Linear dunes occur with barchans—crescent-shaped dunes—and smaller sand bodies on dry basin floors, river valleys, lake margins and piedmonts. A plateau-wide review reports 12,894 km² of Qaidam dunes versus 21,269 km² of yardangs and other wind-eroded forms.^[3] That balance explains why “sand sea” is an incomplete description.

Qaidam is endorheic: it has no outlet to the sea. Perennial and ephemeral streams descend from the mountain rim, including Narin Gol and the Golmud River from the south and Tatalin Gol and Ige He from the north. Some flow reaches terminal lakes; some spreads, evaporates or infiltrates on fans. Measurements from 14 salt lakes and 16 inflowing rivers, brooks and springs show that the dilute inflows are the precursors of chemically varied lake brines.^[5]

The Golmud watershed illustrates the subsurface route. Isotope and groundwater modelling indicate that precipitation and meltwater from the southern mountains recharge the Golmud River and upper fan; river seepage then supplies shallow groundwater that moves north toward the basin depression. Water chemistry evolves from fresh bicarbonate-rich water toward chloride brine through mineral dissolution, evaporation and precipitation of salts.^[6]

Qarhan, in the central-eastern basin, is a salt-lake and playa complex rather than one permanent sheet of open water. A 2024 study maps its full salt-lake area—including dry salt flats—across 94°00′–96°07′ E and 36°40′–37°10′ N, about 170 km east–west, 20–40 km north–south and approximately 5,800 km².^[8] This local measurement must not be substituted for Qaidam's desert or basin area.

Elevation and enclosure create a sharp hydroclimatic contrast. A 2002–2016 analysis combining China Meteorological Administration observations with satellite and land-surface products mapped annual precipitation from roughly 30 mm on parts of the plain to 554 mm in high mountain recharge zones; more than 80% fell in summer. The same analysis found yearly mean temperatures from about 7 °C on the central plain to −14.5 °C at high elevations.^[7] These full-basin ranges should not be read as one “desert average.”

At Qarhan, a 2024 paper reports a station summary of about 24.1 mm annual precipitation and more than 3,500 mm annual evaporation, but it does not state the station normal period or whether the evaporation value is pan or modelled potential evaporation. The figures are therefore useful only as an indicative local aridity contrast.^[8] Mountain snow, rain and ice melt can still sustain terminal flow because the catchment extends far above the exceptionally dry floor.

The Tibetan Plateau and bounding ranges limit moisture reaching the interior, while summer monsoon influence is strongest toward the southeast and westerly circulation matters across the basin.^[2] Exposed sediment and sparse cover allow wind to erode folded beds, move sand and redistribute salt-rich dust.

A Landsat inventory counted only lakes larger than 0.5 km² and used scenes mainly from September–October. Within that definition, mapped basin-wide lake area rose from 1,761.5 ± 88.1 km² in 1977 to 2,285.9 ± 91.4 km² in 2015, while the count increased from 50 to 68.^[9] These are dated remote-sensing estimates with classification uncertainty, not fixed totals for Qaidam's saline water.

The sequence was not a steady expansion: area increased to 1990, declined between 1990 and 2000, then grew most strongly from 2000 to 2015. The study associated precipitation with much of the earlier basin-wide variation and also found major effects from salt-lake exploitation after 2000.^[9] Individual terminal lakes can therefore respond differently to runoff, groundwater, evaporation and water management; a single modern shoreline cannot define the desert.

The Kunlun Mountains form Qaidam's southern sediment and water source, while the Altyn-Tagh separates the basin from the lower Tarim interior and the Taklamakan Desert to the northwest. Those relationships distinguish Qaidam from both the higher plateau beyond the Kunlun and the much lower Tarim Basin.

Within the Desert Hub, Qaidam is best compared as a high, internally drained basin-floor dryland. Its geographic identity comes from the contact of compressed basin strata, mountain-fed fans and groundwater, terminal salt lakes, playa evaporation, yardang erosion and dune deposition—not from a uniform cover of sand.

1. Library of Congress, Library of Congress Subject Headings: T, current free edition, p. T-377 (accessed 30 August 2026). Authority source for Tsaidam Basin (China) and the listed English and romanized variants; it is a basin heading, not a desert-boundary record.
2. Wang, J. et al., “Geological Features and Evolution of Yardangs in the Qaidam Basin, Tibetan Plateau (NW China): A Terrestrial Analogue for Mars”, Journal of Geophysical Research: Planets 123, 2336–2364 (2018). Source for the research-map coordinate envelope, rounded basin dimensions and area, mean elevation, mountain boundaries, surface geology and yardang distribution and processes.
3. Dong, Z. et al., “High-Altitude Aeolian Research on the Tibetan Plateau”, Reviews of Geophysics 55, 864–901 (2017). Source for the separately mapped 34,163 km² aeolian inventory and its 12,894 km² dune and 21,269 km² wind-eroded components.
4. Yin, A. et al., “Cenozoic Tectonic Evolution of the Qaidam Basin and Its Surrounding Regions (Part 3): Structural Geology, Sedimentation, and Regional Tectonic Reconstruction”, Geological Society of America Bulletin 120, 847–876 (2008). Seismic-reflection and stratigraphic source for the synclinorium geometry and phased northern and southern margin deformation.
5. Stober, I., Zhong, J. & Bucher, K., “From Freshwater Inflows to Salt Lakes and Salt Deposits in the Qaidam Basin, W China”, Swiss Journal of Geosciences 116, article 5 (2023). Field chemistry from 14 salt lakes, 16 inflows and 30 evaporite samples; source for endorheic drainage, named inflows and freshwater-to-brine connections.
6. Xiao, Y. et al., “Groundwater Origin, Flow Regime and Geochemical Evolution in Arid Endorheic Watersheds: A Case Study from the Qaidam Basin, Northwestern China”, Hydrology and Earth System Sciences 22, 4381–4400 (2018). Hydrochemistry, isotopes and two-dimensional modelling for the Golmud watershed; local findings are not generalized to every Qaidam river.
7. Bibi, S. et al., “Response of Groundwater Storage and Recharge in the Qaidam Basin (Tibetan Plateau) to Climate Variations from 2002 to 2016”, Journal of Geophysical Research: Atmospheres 124, 9918–9934 (2019). The temperature and precipitation ranges are gridded full-basin results using CMA and satellite products; high mountain values do not describe the desert floor.
8. Wang, D., Liu, C., Shen, L. & Hu, Y., “Quantitative Records of Paleotemperature in Qarhan Salt Lake, Qaidam Basin and Its Relationship with Potassium Deposits”, Scientific Reports 14, 18678 (2024). Source for the mapped Qarhan complex extent, dimensions and local station summary; the publication does not specify the station climatology period or evaporation method.
9. Li, H., Mao, D., Li, X., Wang, Z. & Wang, C., “Monitoring 40-Year Lake Area Changes of the Qaidam Basin, Tibetan Plateau, Using Landsat Time Series”, Remote Sensing 11, 343 (2019); University of South Carolina repository record. Source for the >0.5 km² lake threshold, image timing, mapped 1977 and 2015 areas and uncertainties, interval changes and interpreted drivers.