Water cycle – concept, the definition for kids, types and importance

The water cycle deals with a process that is responsible for describing the circulation of water between the different elements of the hydrosphere, where water, thanks to a series of physical-chemical reactions, can go from a solid, liquid and gaseous state, to This is called the hydrological cycle. Since water is one of the few elements existing on planet earth that has this capacity, the vital liquid as it is known can be found in the sky on earth and in greater quantities in the seas and rivers.

What is the water cycle?

The hydrological cycle or as it is also known the water cycle, is the one that is responsible for describing the continuous and cyclical movement of water on the planet. The cycle begins with the evaporation of the water contained in the seas, rivers and lakes, also the transpiration of plants and sweating in animals. Once the water has evaporated, it condenses forming clouds that, due to their size and weight, end up falling to the surface of the earth, and can be of two types: solid (hail or snow, due to low temperatures) or liquid (rain).

Living beings also play an important role in the hydrological cycle through their metabolic processes by taking in and expelling water. Animals (including man) do it by perspiration by expelling water in the form of vapor through the sweat glands of the skin and plants do it through the leaves.

Water cycle for kids

To explain the water cycle to children, an appropriate language is used so that the little ones relate the concepts of this cycle with real life and help them understand it in a fun way. In addition to this, images of the water cycle, videos and other tools can be used, a way to explain this cycle to the little ones can be like this:

“Water constantly moves through its three states: solid (ice or snow), liquid (seas or rivers) and gaseous (clouds or water vapor). This water cycle has been running for millions of years, so the water we drink today is the same that our good friends the dinosaurs drank. Furthermore, without this fun phenomenon, the planet would not have a place for life as we know it ”.

Water cycle - Scheme

Stages of the water cycle

The water cycle is made up of eight phases or stages which will be detailed and illustrated below:


In this phase the heat radiated by the sun heats the water in the seas, rivers, lakes and oceans and the phenomenon of evaporation occurs. It is when water transforms from a liquid to a gaseous state and moves from the surface of the earth to the atmosphere.


Water condensation occurs when it rises and condenses, causing the formation of clouds and haze, it is made up of very tiny drops of water.

Water Cycle - Clouds


In this phase, the condensed water from the atmosphere descends to the surface of the earth, transformed into small drops of water, known as rain. But in areas of low or very cold temperatures, the water goes from a liquid to a solid state, known as solidification, and falls to the ground in the form of snow or hail. then the melting process occurs, it is when the thaw occurs and the water goes back to its liquid state.

Water cycle - Rain


At this stage, the water reaches the ground, penetrates the pores and becomes groundwater. The proportion of filtered water and water that circulates on the surface depends on the permeability of the substrate, the slope and a large part of the infiltrated water returns to the atmosphere through evaporation or even, through the transpiration of plants, which they extract this water with more or less extensive and deep roots.


It is the name given to the different means by which water moves down the slopes of the earth’s surface in liquid form. Runoff is the main geological agent of erosion and sediment transport.

Underground circulation

It is a process very similar to runoff but in underground areas and occurs in the direction of gravity. This phenomenon occurs in two ways: First, the one that arises in the vadose zone, especially in karstified rocks called limestones, always remaining in the direction of the downward slope. Second, what happens in aquifers in the form of interstitial water, which fills the pores of a permeable rock, and can even be overcome by phenomena that involve pressure and capillarity.


It occurs with thawing, and it is when the water changes from a solid state (snow) to a liquid.


Represents the decrease in temperature within a cloud below 0 ° C, there is precipitation of snow or hail because the water vapor or the water itself freezes, constituting the main difference between the two concepts, which in the case of snow is a solidification of water in the cloud, which occurs at a low temperature.

As moisture and small water droplets in the cloud freeze, snowflakes and polymorphic ice crystals form, that is, they take forms visible under the microscope, while in the case of hail, the rapid increase in the drops of water that form a cloud, is what generates the formation of ice, which produces hail and increases its size.

Water Cycle - Snow

Importance of the water cycle

Many have ever wondered why the water cycle is so important. The answer to this question is that it is a fundamental process for the maintenance of life on earth, as well as for the optimal sustenance of all terrestrial ecosystems. In the same way, it determines the variation of the climate and interferes with the level of the oceans, seas, rivers and lakes.

Human beings are responsible for preserving the correct functioning of this cycle, since it was precisely the action of man that caused the contamination of the biosphere and climatic changes, putting at risk the distribution of liquid elements and, therefore, the life on earth.

Each of the stages of this cycle develops benefits for all living beings that inhabit planet earth and among them is: temperature regulation, water purification in springs, hydration or feeding of plants and reserves of water (H2O) on the planet.

Images about the water cycle

Below are different coloring images of the water cycle, as well as diagrams showing the cycle.

Frequently Asked Questions about Water Cycle

What is the water cycle?

Process that is responsible for describing the circulation of water between the different elements of the hydrosphere. It begins with the evaporation of the water contained in the seas, rivers and lakes. Once the water has evaporated, it condenses into clouds that, due to their size and weight, end up falling to the surface of the earth.

What is the water cycle for?

  • To maintain the balance of the ecosystem.
  • The regulation of temperature.
  • Water purification in springs
  • The hydration or feeding of plants and the reserves of water (H2O) on the planet.

Why is the water cycle important?

The water cycle is essential to maintain life on planet earth and for the sustenance of each terrestrial ecosystem. In the same way, it determines the climatic variations and interferes in the seas, lakes, rivers and oceans.

What climatic factors influence the water cycle?

There is a factor that directly influences and is the temperature, since it is thanks to it that the cycle begins when the water evaporates and turns it into a cloud and then falls to the earth through precipitation.

By what other name is the water cycle known?

This cycle is also known as the hydrological cycle.