What Goes Around Comes Around - Background

The water that cave men drank a long, long time ago is the same water that we drink today. This is because of the water cycle: a never ending process that transports water from the earth, to the atmosphere, and back to the earth.

Four Stages of the Water Cycle

1. Evaporation: The sun shines on the earth, causing the water from oceans, lakes, rivers and puddles to heat up. This heated water turns into water vapor and rises into the air. This process is called evaporation. Another way for water to enter the atmosphere is through transpiration. This occurs as water is evaporate from trees and plants.

2. Condensation: Water vapor (gas) is carried through the atmosphere by wind and air currents. When this air mass cools, a cloud is formed.

3. Saturation: The cloud grows larger by collecting more and more water vapor. As more and more collects within a cloud, it becomes saturated with water droplets.

4. Precipitation: When a cloud can no longer collect and hold any more vapor, the vapor will fall in the form of precipitation. Precipitation can be rain, snow, hail, sleet, etc., and it can fall anywhere on the earth.

5. Collection: The fifth step can take many forms. Precipitation that falls back into the oceans, lakes, rivers, and puddles will start the evaporation process all over again. Other types of precipitation, such as snow and ice, will melt when the weather is warm and flow back into a body of water. This is called surface runoff. The water can also filter through the ground and be used by plants, or it could go further into the ground, through percolation, and become groundwater. Groundwater will then eventually run back into a body of water.

Definitions

condensation - water vapor is cooled and turns into a liquid

evaporation - water turns into a water vapor through the sun's heat

percolation - water filters into the ground through tiny holes in the soil

saturated - a cloud is so full of water that no more can be collected in it

surface runoff - water on the surface of the earth that flows into a body of water

transpiration - water from the surface of plants becomes water vapor through the sun's heat

What Goes Around Comes Around

Introduction

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Barnyard Business

Water Woes

What Goes Around Comes Around

Walk in the Woods

Athens District High School
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Text by Keri Oosterhof