Playas

• These are sometimes known as inland drainage basins.
• Due to the fact that there are no permanent drainage patterns in deserts any rain that falls either evaporates or infiltrates into the soil or runs off and drains into basins.
• Basins are depressions.
• When rain falls temporary rivers that flow in canyons/bahadas are formed and these may eventually drain in a basin/depression.
• These rives form lakes in these depressions.
• When these lakes dry up due to evaporation they are turned into salt flats.
• These temporary lakes and salt flats are known as playas or sebkhas.
• Examples of these can be found in the Sahara desert.
• When alluvium is deposited at the edge and overlies the edge of the pediment around the playa it is known as a peri-pediment.
• Most deserts are characterised by inland drainage basins as few rivers e.g. the Nile have enough water supply to flow and persist through the deserts.
• Most form inland drainage basins/lakes/playas.

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