It is 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 pass from a solid, liquid and gaseous state, to this it 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.
Water on the planet is present in three different states, such as gaseous, liquid and solid, passing from one to another thanks to processes such as the evaporation of water on earth, precipitation of the water contained in the clouds, among others., without causing variations in the total amount of water contained in the plant.
Water cycle or hydrological cycle
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The hydrological cycle or as it is also known the water cycle, is the one in charge of describing the continuous and cyclical movement of water on the planet. Water can change and appear in its states such as liquid, ice and vapor in various stages of the cycle, these changes can occur in a very short time or in many years.
Despite the fact that the water balance on the planet remains more or less constant over time, individual water molecules can circulate rapidly. The sun is the one who directs this cycle by heating the water in the oceans. A part of this water evaporates into water vapor. Ice and snow can evaporate into water vapor.
The water cycle takes place in two ways: internal and external. The internal cycle consists of the formation of magmatic water through chemical reactions, the water that is formed there can rise to the surface at the moment when volcanoes erupt or through hot springs.
The external cycle on the other hand begins with the evaporation of the water contained in the reservoirs, such as seas, rivers and many others, also the transpiration of the plants and the sweating of the animals, they contribute water that is evaporated and raised to the clouds and that Thanks to the low temperatures, it cools down and condenses in the clouds, transforming into water.
Then the drops produced by the condensation unite, thus forming clouds that, due to their size and weight, end up falling to the surface of the earth, being of two types solid (hail or snow, due to low temperatures) or liquid.
When water reaches the surface it can have several destinations, one of them is its use in the organic processes of living beings, another part is infiltrated through the pores of the earth, being placed in underground tanks and finally thanks to the runoff that causes the water to slide through the different surfaces until it reaches the seas, lakes and rivers.
What is water
Water is a liquid substance that is formed from the union of two atoms of hydrogen and oxygen, its formula is H2O and it is a very stable molecule. Water is a very special natural resource and a priority in the conservation of the earth, without it the survival of any type of life would be impossible. 70% of the planet's surface is presented in the form of oceans, seas, rivers, lakes, lagoons and springs.
Water is essential for most of the bodily functions of human beings. They could suppress all food for weeks, but they would die in a matter of days without drinking water, more than half of the body weight of the human being corresponds to water.
The human being consumes a large part of the water in the form of a drink, but almost all foods contain large amounts of water, for example, fruits and vegetables contain up to 90% and the driest products between 25 and 50%. Besides this, some animals, such as silverfish, no need to drink water, as their metabolism can be produced from the carbohydrate carbon and oxygen.
The physical states of water are solid, liquid and gaseous.
- Solid is presented in the form of ice, generally in places where temperatures are very low below 0 ° C, it can be in glaciers, polar caps, it can also be the form of snow and hail.
- Liquid occurs in the lakes, rivers, seas and oceans that the planet covers, this state of the water takes the form of the container that contains it and can remain so only at ambient temperatures.
- Gaseous is when water appears in the form of vapor, and it can be seen as clouds and fog, also when water is exposed to very strong heat or high temperatures, it begins its physical change from liquid to water vapor.
Biogeochemical cycle of water
It consists of the circulation of matter from the living world to the abiotic environment and vice versa. These are natural processes that recycle elements in different chemical forms from the environment to organisms, in a reciprocal way. Water, carbon, oxygen, nitrogen, phosphorus, and other elements travel through these cycles, connecting the living and non-living components of the earth.
The biogeochemical cycle of water consists of the sequence of a phenomenon by means of which water passes from the earth's surface, in the vapor phase, to the atmosphere and again returns to the earth in its liquid and solid phases. Water is transferred from the earth's surface to the atmosphere in the form of water vapor, due to the evaporation of water in a direct way, to the transpiration of plants and animals by sublimation, or direct passage of solid water to water steam.
Phases of the water cycle with images
The water cycle is made up of eight phases or stages which will be detailed and illustrated below:
Evaporation
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 changes from a liquid to a gaseous state and moves from the surface of the earth to the atmosphere.
Condensation
The condensation of water occurs when it rises and condenses, causing the formation of clouds and mist, it is made up of very tiny drops of water.
Precipitation
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 thawing occurs and the water goes back to its liquid state.
Infiltration
In 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.
Runoff
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 pore water, which fills the pores of a permeable rock, and can even be overcome by phenomena that involve pressure and capillarity.
Fusion
It occurs with thawing and where the water changes from a solid (snow) to a liquid state.
Solidification
Represents the decrease in temperature within a cloud below 0 ° C, there is snow or hail precipitation because water vapor or 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.
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.
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 working 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 ”.
How to make a model of the water cycle
On the web there are a wide variety of videos and tutorials on how to make a model of the water cycle, ranging from very simple which can be made with recyclable material, to very sophisticated ones made with wood and water pumps, used in aquariums to generate real movements. The most common materials are:
- Drawing of the water cycle.
- Scissors.
- Paints of various colors.
- Paperboard.
- Hot glue guns.
- White glue.
- Clay.
To have a better idea of how to make a model, a video is shared below that can serve as a guide when creating the water cycle in three-dimensional form
