The Parts of the Water Cycle

From the time when the Earth was formed, water has been important for life. Surprisingly, there is still an adequate supply of water on Earth today; this is possible because of the natural recycling of water, known as the water cycle. The water cycle replenishes and cleans water that is present on Earth through a number of natural processes, and it ensures that all living things will have enough water to consume and use.

Evaporation is the process by which water is converted into water vapor. In the water cycle, it occurs as a result of heat from the sun. About 80% of the evaporation that occurs during the water cycle comes from the oceans, with the remainder occurring on inland water bodies, plant surfaces, and land. The ideal conditions for evaporation are high temperature and wind speed as well as low humidity. The water vapor that is formed from the evaporation of water on Earth will ascend to the sky, where it will undergo the process of condensation.

Condensation is the reverse process of evaporation, and it turns water vapor back into water. When water vapor is in the sky, the water molecules will bond with particles such as salt, dust, and smoke to become cloud droplets. In turn, these droplets will combine with one another to form clouds. As the clouds grow, the low temperature in the sky will cause turn them into rainwater. Rainwater, or precipitation, is water that falls off from the bases of clouds.

Precipitation refers to the release of water from the atmosphere, and it can appear in the form of rain, snow, or hail. Precipitation delivers water to the surface of the Earth, and it will end up in the oceans or inland water bodies, or on land. The rate of precipitation varies from one geographical location to another, and it is dependent on the climate of each specific region. Rain is the most common form of precipitation.

When precipitation falls, some of it will seep into the ground and run through pores in the soil. There are different layers of soil, and they all hold certain amounts of water. Water that infiltrates the ground will eventually end up in the saturation layer, which is a layer that is mostly made up of groundwater. As it continues to rain, the saturation layer will expand, and groundwater will move towards the surface and become stream, river, or lake water.

All the processes of the water cycle play an important role in the replenishing and distribution of water supply on Earth, and the natural recycling of water will not be possible without any of them. There are other processes that also contribute to the water cycle, including sublimation and transpiration; but the abovementioned processes are the main components of the cycle.

• The Hydrologic Cycle: Clear illustrated explanation of different parts of the water cycle.

• Round and Round It Goes!: This web page contains images and descriptions of all water cycle processes.

• Illustrated Water Cycle: An animation that shows how a water cycle works.

• Evaporation: Several diagrams that explain the process of evaporation.

• Condensation: Brief description of the condensation process in the water cycle.

• Precipitation: Find out how precipitation works and try a precipitation quiz.

• Interactive Water Cycle: An interactive lesson on the water cycle.

• Droplet and the Water Cycle: Interesting educational game that can help children learn about the water cycle.

• Water Cycle Activities: Activities that show the functions of different processes of the water cycle.