Sheet flood
Also called: Sheet wash · Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 11, Ch 6 "Landforms and their Evolution"
Meaning
A sheet flood is a broad, shallow flow of water across a desert surface after a rare, short burst of heavy rain. The water spreads out as a wide sheet instead of staying in a channel. It washes away loose, broken rock. Together with wind, sheet floods do much of the general erosion in deserts. They also help cut pediments, the gently sloping rocky floors at the foot of desert mountains. So running water matters a lot even in dry lands.
Example
In the Thar desert of western Rajasthan, rare heavy showers send sheets of water across the bare ground. They carry sand and gravel down into low basins.
Don't confuse with
- Sheet erosion: in humid regions, rainwater flows over the land as a thin sheet and strips off topsoil, and the flow then gathers into rills and gullies. A sheet flood is a sudden, larger flow in a desert after rare heavy rain.
Related concepts
- Aeolian processes
- Deflation
- Wind abrasion
- Erg, reg and hamada
- Pediment
- Parallel retreat of slopes
- Pediplain
- Inselberg
- Playa
- Deflation hollow