Word of the Day – Tuesday, April 17th



Word of the Day


Clever Clue of the Month

The Cruciverbalist


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RILL (rill)

A very small brook
Common clues:
Tiny stream; Streamlet; Small brook; Moon valley; Lunar valley
Crossword puzzle frequency: once a year
Frequency in English language: 74056 / 86800

Video: Small brook at bottom of canyon

A rill is a narrow and shallow incision into soil resulting from erosion by overland flow that has been focused into a thin thread by soil surface roughness. Rilling, the process of rill formation, is common on agricultural land and unvegetated ground.

Some rills will continue to grow, as they are widened and/or deepened by the runoff which flows through them. Other rills may decline in importance as sediment is deposited within them. Eventually, a hydrologically efficient rill network will be formed. The development of such a network is an example of self-organisation.

In a few cases, rills may continue to grow and become gullies.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Rill".