Rapid
A rapid is a section of a river where the river bed has a relatively steep gradient causing an increase in water velocity and turbulence. A rapid is a hydrological feature between a run (a smoothly flowing part of a stream) and a cascade. A rapid is characterised 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.
Read more about Rapid.
Famous quotes containing the word rapid:
“More rapid than eagles his coursers they came,
And he whistled, and shouted, and called them by name:
“Now, Dasher! now, Dancer! now, Prancer and Vixen!
On, Comet! on, Cupid! on, Donder and Blitzen!
To the top of the porch! to the top of the wall!
Now dash away! dash away! dash away all!””
—Clement Clarke Moore (1779–1863)
“In clear weather the laziest may look across the Bay as far as Plymouth at a glance, or over the Atlantic as far as human vision reaches, merely raising his eyelids; or if he is too lazy to look after all, he can hardly help hearing the ceaseless dash and roar of the breakers. The restless ocean may at any moment cast up a whale or a wrecked vessel at your feet. All the reporters in the world, the most rapid stenographers, could not report the news it brings.”
—Henry David Thoreau (1817–1862)
“But parents can be understanding and accept the more difficult stages as necessary times of growth for the child. Parents can appreciate the fact that these phases are not easy for the child to live through either; rapid growth times are hard on a child. Perhaps it’s a small comfort to know that the harder-to-live-with stages do alternate with the calmer times,so parents can count on getting periodic breaks.”
—Saf Lerman (20th century)