![](http://www.alamy.com/thumbs/6/984AB201-B465-44E8-A6FE-7F1DF8B9DFCD/FFW902.jpg)
A simple water level metering system made of a ruler on a stick or plank that is lowered into the water.
Size: 4000px × 2667px
Photo credit: © Ingemar Magnusson / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: changeability, comparison, conservation, control, cracks, creek, environment, environmental, experiment, fluctuation, flux, industrial, industry, interval, lake, level, measure, measurement, metering, moss, nature, number, outdoor, plank, point, river, rock, ruler, sea, side, stone, stream, surface, survey, system, tide, variability, variation, water