Elusive, but ecologically vital, Namibia's Ugab River only flows above ground for a few days each year. The subterranean waters underlying this ephemeral river, however, are shallow enough in places to fill hollows and sustain a wildlife population that includes the rare desert elephant.
This image was acquired by Landsat 7’s Enhanced Thematic Mapper plus (ETM+) sensor.
Image provided by the USGS EROS Data Center Satellite Systems Branch as part of the Earth as Art II image series
