A Waterfall is a Place Where Flowing Water Rapidly Drops in Elevation as It Flows Over a Steep Region or a Cliff

7/30/2019 A Waterfall is a Place Where Flowing Water Rapidly Drops in Elevation as It Flows Over a Steep Region or a Cliff

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A waterfall is a place where flowing water rapidly drops in elevation as it flows over a

steep region or a cliff. Waterfalls are considered to be one of the most beautiful

phenomena in nature.[1] Some waterfalls are used to generate hydro-electricpower.

[edit] Formation

Formation of a waterfall

Waterfalls are most commonly formed when a river is young.

[1]

At these times thechannel is often narrow and deep. When the river courses over resistant rock, erosionhappens slowly, while downstream the erosion occurs more rapidly.[1] As the watercourse

increases its velocity at the edge of the waterfall, it plucks material from the riverbed.

Whirlpools created in the turbulence as well as sand and stones carried by thewatercourse increase the erosion capacity.[1]This causes the waterfall to carve deeper into

the bed and to recede upstream. Often over time, the waterfall will recede back to form a

canyon or gorge downstream as it recedes upstream, and it will carve deeper into the

ridge above it. The rate of retreat for a waterfall can be as high as one and half metres peryear.[1]

Often, the rockstratumjust below the more resistant shelf will be of a softer type,

meaning that undercutting due to splashback will occur here to form a shallow cave-likeformation known as a rock shelterorplunge pool under and behind the waterfall.

Eventually, the outcropping, more resistant cap rock will collapse under pressure to add

blocks of rock to the base of the waterfall. These blocks of rock are then broken down

into smaller boulders by attritionas they collide with each other, and they also erode thebase of the waterfall byabrasion, creating a deep plunge pool or gorge.
http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Hydro-electrichttp://en.wikipedia.org/wiki/Hydro-electrichttp://en.wikipedia.org/w/index.php?title=Waterfall&action=edit&section=1http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Whirlpoolhttp://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Rock_shelterhttp://en.wikipedia.org/wiki/Plunge_poolhttp://en.wikipedia.org/wiki/Plunge_poolhttp://en.wikipedia.org/wiki/Outcrophttp://en.wikipedia.org/wiki/Attrition_(weathering)http://en.wikipedia.org/wiki/Attrition_(weathering)http://en.wikipedia.org/wiki/Abrasion_(geology)http://en.wikipedia.org/wiki/Abrasion_(geology)http://en.wikipedia.org/wiki/Abrasion_(geology)http://en.wikipedia.org/wiki/File:WaterfallCreationDiagram.svghttp://en.wikipedia.org/wiki/File:WaterfallCreationDiagram.svghttp://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Hydro-electrichttp://en.wikipedia.org/w/index.php?title=Waterfall&action=edit&section=1http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Whirlpoolhttp://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Rock_shelterhttp://en.wikipedia.org/wiki/Plunge_poolhttp://en.wikipedia.org/wiki/Outcrophttp://en.wikipedia.org/wiki/Attrition_(weathering)http://en.wikipedia.org/wiki/Abrasion_(geology)


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Baatara gorge waterfall nearTannurin,Lebanon

Streams become wider and shallower just above waterfalls due to flowing over the rockshelf, and there is usually a deep pool just below the waterfall because of the kinetic

energy of the water hitting the bottom. Waterfalls normally form in a rocky area due to

erosion. After a long period of being fully formed, the water falling off the ledge willretreat, causing a horizontal pit parallel to the waterfall wall. Eventually, as the pit grows

deeper, the waterfall collapses to be replaced by a steeply sloping stretch of river bed. [1]

A river sometimes flows over a large step in the rocks that may have been formed by a

fault line. Waterfalls can occur along the edge of aglacial trough, whereby a stream orriver flowing into a glaciercontinues to flow into a valley after the glacier has receded or

melted. The large waterfalls in Yosemite Valley are examples of this phenomenon, which

is referred to as a hanging valley. Another reason hanging valleys may form is where tworivers join and one is flowing faster than the other.[1]

Types

Main article: List of waterfalls by type

Dark Hollow Falls, nearSkyline Drive, Virginia, is an example of a cascade waterfall
http://en.wikipedia.org/wiki/Baatara_gorge_waterfallhttp://en.wikipedia.org/w/index.php?title=Tannurin&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Tannurin&action=edit&redlink=1http://en.wikipedia.org/wiki/Lebanonhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Fault_(geology)http://en.wikipedia.org/wiki/Glacial_troughhttp://en.wikipedia.org/wiki/Glacial_troughhttp://en.wikipedia.org/wiki/Glacierhttp://en.wikipedia.org/wiki/Yosemite_Valleyhttp://en.wikipedia.org/wiki/Hanging_valleyhttp://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/List_of_waterfalls_by_typehttp://en.wikipedia.org/wiki/Skyline_Drivehttp://en.wikipedia.org/wiki/Virginiahttp://en.wikipedia.org/wiki/File:Dark_Hollow_Falls.jpghttp://en.wikipedia.org/wiki/File:Dark_Hollow_Falls.jpghttp://en.wikipedia.org/wiki/File:Baatara_gorge.JPGhttp://en.wikipedia.org/wiki/File:Baatara_gorge.JPGhttp://en.wikipedia.org/wiki/Baatara_gorge_waterfallhttp://en.wikipedia.org/w/index.php?title=Tannurin&action=edit&redlink=1http://en.wikipedia.org/wiki/Lebanonhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/Fault_(geology)http://en.wikipedia.org/wiki/Glacial_troughhttp://en.wikipedia.org/wiki/Glacierhttp://en.wikipedia.org/wiki/Yosemite_Valleyhttp://en.wikipedia.org/wiki/Hanging_valleyhttp://en.wikipedia.org/wiki/Waterfall#cite_note-fenh-0http://en.wikipedia.org/wiki/List_of_waterfalls_by_typehttp://en.wikipedia.org/wiki/Skyline_Drivehttp://en.wikipedia.org/wiki/Virginia


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Block: Water descends from a relatively wide stream or river.

Cascade: Water descends a series of rock steps.

Cataract: A large, powerful waterfall.

Fan: Water spreads horizontally as it descends while remaining in contact with

bedrock.

Horsetail: Descending water maintains some contact with bedrock. Plunge: Water descends vertically, losing contact with the bedrock surface.

Punchbowl: Water descends in a constricted form and then spreads out in a wider

pool.

Segmented: Distinctly separate flows of water form as it descends.

Tiered: Water drops in a series of distinct steps or falls.

Multi-step: A series of waterfalls one after another of roughly the same size each

with its own sunken plunge pool.
http://en.wikipedia.org/wiki/Bedrockhttp://en.wikipedia.org/wiki/Bedrock

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A Waterfall is a Place Where Flowing Water Rapidly Drops in Elevation as It Flows Over a Steep Region or a Cliff