USGS - science for a changing world

The USGS Water Science School

Go to a page to view the Kid's Water Cycle diagram Go back to the water cycle diagram.
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A plant with a plastic bag wrapped around some of the leaves, with condensed transpired water on the inside of the plastic bag.

After a plastic bag is wrapped around part of a plant, the inside of the bag becomes misty with transpired water vapor.
Credit: Ming Kei College, Hong Kong


Take a breath and breath out. There you go, you just participated in the Global Water Cycle. Your breath contains water (breathe on a glass pane to see it appear before your very eyes). When a person breaths, the term is called "respiration", similar to when you sweat, which is the term "perspiration".

All the plants around you are breathing, too, and releasing water with every breath (although their breathing is much different than yours). The term is called "transpiration", and although a brussel sprout doesn't have a mouth, it has tiny holes in its leaves that allow water to leave the leaf and go back into the air. So, plants "transpire" water while humans "respire" and "persipire" water.

But the big word is "Evapotranspiration", which is just a combination of "evaportation" plus "transpiration". This just means that not only are plants transpiring water from their leaves, water is evaporating from the soil all around them.

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Page Last Modified: Thursday, 06-Mar-2014 14:30:54 EST