Since it became externally drained, the fluvial dynamics of the Ouarzazate foreland basin has been
dominated by erosive processes due to a base level fall. The basin landscape is dominated by extensive
Quaternary deposits aggraded by the transverse rivers draining the High Atlas Mountains. These deposits
accumulated in valleys and pediments incised in the basin Tertiary infill, characterized mostly by fine-grained
and soft sediments. Evidences of fluvial captures are abundant in recent times and throughout the Quaternary,
in a scenario where there is more incision efficiency in the interfluves’ secondary streams (characterized by
fine-grained or sediment-free pediments) than in the main transverse rivers (characterized by thick gravel
deposits). Satellite imagery, elevation data and field observations demonstrate how minor streams increase
their catchment areas by headward erosion, creating extensive pediments lying under the main rivers and
producing captures of the main rivers. This study demonstrates the unsteady-state of the drainage network of
the Ouarzazate basin and its recent reorganization, apparently uncoupled from tectonic or climatic processes
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