base level n.
The lowest level to which a land surface can be reduced by the action of running water.

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      in hydrology and geomorphology, limit below which a stream cannot erode. Upon entering a still body of water, a stream's velocity is checked and thus it loses its eroding power; hence, the approximate level of the surface of the still water body is the stream's baselevel. If a stream enters the sea, its baselevel is sea level; (sea level) this is known as ultimate baselevel. If a stream enters a lake, the lake level acts as a temporary baselevel for all parts of the stream above that elevation. All continental areas tend to be eroded down to ultimate baselevel, or sea level, but uplifting of the Earth's crust and variations in sea level prevent this from happening except in rare, small areas.

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Universalium. 2010.

См. также в других словарях:

  • baselevel — I. ˈ ̷ ̷| ̷ ̷ ̷ ̷ noun Etymology: base (I) + level : the level below which a land surface cannot be reduced by running water II. transitive verb : to reduce to or toward the condition of a plain at baselevel …   Useful english dictionary

  • baselevel plain — ˈ ̷ ̷ˌ ̷ ̷ ̷ ̷ noun : a plain produced by the degradation of a region to its baselevel compare peneplain …   Useful english dictionary

  • river — river1 riverless, adj. riverlike, adj. /riv euhr/, n. 1. a natural stream of water of fairly large size flowing in a definite course or channel or series of diverging and converging channels. 2. a similar stream of something other than water: a… …   Universalium

  • valley — valleylike, adj. /val ee/, n., pl. valleys. 1. an elongated depression between uplands, hills, or mountains, esp. one following the course of a stream. 2. an extensive, more or less flat, and relatively low region drained by a great river system …   Universalium

  • Geography of the United States Pacific Mountain System — Physiographic regions of the U.S. Interior. (See legend) For purposes of description, the physical geography of the United States is split into several major physiographic divisions, one being the Pacific Mountain System. Please refer to the… …   Wikipedia

  • California State Route 128 — Infobox road state=CA type=SR route=128 section=428 maint=Caltrans length mi=120.52 length round=2 length ref= [ [ January 1, 2006 California Log of Bridges on State Highways] ] direction… …   Wikipedia

  • Amok (video game) — Infobox VG| title = Amok developer = Lemon publisher = Scavenger (USA, Europe) Koei (Japan) Tec Toy (Brazil) designer = engine = released =1996 (Microsoft Windows) January 17, 1997 (USA) June 20, 1997 (Japan) genre = Action modes = Single player… …   Wikipedia

  • peneplain — peneplanation /pee neuh pleuh nay sheuhn/, n. /pee neuh playn , pee neuh playn /, n. Geol. an area reduced almost to a plain by erosion. Also, peneplane. [1885 90; PENE + PLAIN1] * * * Gently undulating, almost featureless plain near sea level.… …   Universalium

  • rejuvenation —    A process that interrupts an active erosional or development cycle and initiates a new cycle. Rejuvenation is most commonly achieved in the karst and speleogenesis context by erosional baselevel changes caused by relative uplift (or sea level… …   Lexicon of Cave and Karst Terminology

  • relict karst —    A karst area that exists within the contemporary system, but has been removed from the situation in which they developed, usually as a result of baselevel changes …   Lexicon of Cave and Karst Terminology

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