water level

water level

the water line of a boat or ship

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

water level

[′wȯd·ər ‚lev·əl]

(building construction)

water table

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

water level

A simple device for establishing two points at the same elevation; consists of a water-filled flexible hose (from which air has been excluded) with a piece of glass tubing at each end; the water level is observed through the glass tubing.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Water Level

 

in rivers and lakes, the position of the free water surface referred to some horizontal surface of constant elevation. The surface of reference may be either relative or absolute, that is, either some plane of arbitrary elevation (the plane is the datum level) or the surface corresponding to the mean water level of the ocean at the shores of the continents.

Variations of the water level in a river occur primarily because of changes in flow rate, warping of the channel, or the backwater effect. In an inland body of water, variations of the water level may result from a change in the ratio of the elements in the water balance, surges, or seiches. Annual water level variations depend on climatic conditions and range from a few centimeters to 2–3 m in lakes and up to 5–12 m in large rivers.

Water level observations are made at water level measuring stations.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.