167 The characteristic polygonal structure of the takyrs, seen here in the Aydingkol Depression (492 ft [150 m] below sea level) in the Tarim endorheic basin (Xinjiang, China), between the Takla Makan and the A-la Shan deserts.
Central Asia is a set of endorheic basins. Only at the eastern tip does the Yellow River (Huang He), which flows into the China Sea, drain a small part of the area.
The A-la Shan Desert is, in fact, a set of endorheic basins that often have abundant underground water.
Apart from this, at the ends of these chains--at altitudes between 4,921-6,562 ft (1,500-2,000 m)--there are smaller depressions, called bolsones, that form small endorheic basins fed by intermittent watercourses.
The fact that they are endorheic basins has led to the formation of vast areas of saline soils that often cover the depressions.
Keywords: SRTM, quantitative geomorphology, endorheic basins, South America
Endorheic basins are characteristic geomorphic features in southern South America.
The aim of this paper is to demonstrate the use of SRTM data for continental-scale quantitative geomorphology and to draw attention to the geographic distribution of endorheic basins in South America south of 19[degrees]S.
To identify endorheic basins, topographic depressions in the DEM were filled using the algorithm after Planchon and Darboux (2001) with enforced drainage on flats which is implemented in the TAS (Terrain Analysis System) software version 2.0.9 by John Lindsay (Lindsay, 2005).
Only confirmed endorheic basins were included in the following analyses.
Of the 289 objects e"2 [km.sup.3], 251 were validated to be endorheic basins. However, because all 38 erroneously identified basins are small (<25 [km.sup.3]), they account for only 1.1% of the total volume (Table 1).
The total volume of the 251 confirmed endorheic basins in South America south of 19[degrees]S with volumes e"2 [km.sup.3] was found to be 20404 [km.sup.3].