. Ancient mega rivers, inland deltas and lake basins of the eastern sahara: a radar remote sensing investigation
Presentation
Overview
Overview
Description
The Sahara of North Africa includes some of the driest areas on Earth. Yet, its landforms kept a record of past humid climates. During wet phases, the region was green and contained permanent rivers, inland deltas and lakes. When the wet periods ended at about 5.5 ka, the Sahara transformed into a hyperarid desert and its original surface was covered by sand. The vast sand cover has inhibited revealing these fluvial features. Radar waves from space, however, can penetrate the sand cover and reveal underlying topography. Here, radar images from Radarsat, as well as topographic data from SRTM, were used along with a GIS surface-flow model to map such sand-buried features. Data processing unveiled two distinct river systems, and two large lake basins.
