(Redirected from Rapids)

Violent water below Niagara Falls
A 'rapid' is a section of a
river where the river bed has a relatively steep
gradient causing an increase in water
flow and
turbulence. A rapid is a
hydrological feature between a ''run'' (a smoothly flowing part of a
stream) and a ''
cascade''. A rapid is characterized by the river becoming shallower and having some
rocks exposed above the flow surface. As flowing water splashes over and around the rocks, air bubbles become mixed in with it and portions of the surface acquire a white colour, forming what is called "
whitewater". Rapids occur where the
bed material is highly resistant to the erosive power of the stream in comparison with the bed downstream of the rapids. Very young streams flowing across solid rock may be rapids for much of their length.
See also
★
Fluid dynamics - for academic explanation.
★
International Scale of River Difficulty - for classification of rapids.
★
Rheophile - organisms that live in fast flowing water.
★
Riffle - A fast moving portion of a stream without the vigour of a rapid
★
Whitewater - for factors related to rapids.
References
★ Mason, Bill. Path of the Paddle, 1984, Northword Press, Minoqua, WI.