Satellite image of the neighboring Coipasa and Uyuni salt flats.

  

The connection between the Coipasa and Uyuni Salt Flats, Bolivia


Victor M. Ponce, Luis G. Ariza, y
Rodolfo J. Vera Quispe


19 June 2017


The salt flats of Coipasa and Uyuni are two large natural accumulations of salt (salt lakes) located within the endorheic hydrographic basin of the Peruvian-Bolivian altiplano. The Coipasa salt flats, in the department of Oruro, have an area of 2 239 km2 and an average altitude of 3,657 meters. However, it should be noted that a very small fraction of the Coipasa salt flats lie in the neighboring country of Chile. The Uyuni salt flats, in the department of Potosí, has an area of 10 085 km2 and an average altitude of 3,653 above m.s.l. (Chua and Ponce, 2010). This article documents the existence of a hydraulic connection between the two salt flats.

Figure 1 shows an aerial perspective of the Coipasa salt flats. Figure 2 shows the old (remnant) trace of the stream or channel that connects the Coipasa salt flats (near the upper right corner) with the Uyuni salt flats (lower left corner). This stream borders the Tunupa volcano in the vicinity of Cacota, Laguna Cruz and Castillona, eventually leading to the Uyuni salt lake, as shown in Fig. 3.

Coipasa salt flats
Google Earth ©

Fig. 1  The Coipasa salt flats.

Coipasa and Uyuni salt flats
Google Earth ©

Fig. 2  Connection between the Coipasa and Uyuni salt flats, around the Tunupa volcano.

Aerial perspective of Coipasa and Uyuni
Google Earth ©

Fig. 3  Aerial perspective of the Coipasa dn Uyuni salt flats, with the Tunupa volcano in the middle.

Based on the information examined, it can be concluded that there is a connection between the two salt flats. The difference in elevation is estimated at 5 m, with the flow originating in the salt flats of Coipasa and ending in the salt flats of Uyuni. Therefore, the latter is the terminus of the drainage of the Peruvian-Bolivian altiplano basin, which contains, upstream, Lake Titicaca, and downstream, the salt flats of Coipasa and Uyuni, among others (Chua and Ponce, 2010).

A more detailed analysis is obtained by applying a geographic information system (GIS) to the satellite images of the Coipasa and Uyuni drainages. Figure 4 shows the contiguous watersheds of both salt flats.

[Click on image to display]
Salar de Uyuni cuencas

Fig. 4  The hydrographic basins of the Coipasa and Uyuni salt flats.

Figure 5 shows the hydraulic connection between the Coipasa and Uyuni salt flats. The difference in elevation, with the Coipasa salt flats upstream and the Uyuni salt flats downstream, is approximately 6 m. It is inferred that during extraodinary floods, the water of Coipasa lake has flowed towards Uyuni lake. Therefore, it is confirmed that Uyuni is the terminus of the drainage of the Peruvian-Bolivian altiplano basin.

[Click on image to display]
Salar de Uyuni quebrada

Fig. 5  Hydraulic connection between the Coipasa salt flats, upstream, and the Uyuni salt flats, downstream.


Chua, J. H., and V. M. Ponce. 2010. Drainage basin of the Altiplano, South America. http://ponce.sdsu.edu/chua/altiplano_drainage_basin.html 15 October 2010.

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