The Water Cycle in Nature

Posted on Jan 20, 2021      79


The water cycle is the most important process on our planet, which provides life for all living things, from small animals and plants to humans. Water is necessary for the existence of all organisms, without exception. It takes part in many chemical, physical, biological processes. Water covers 70.8% of the Earth’s surface and makes up the hydrosphere, part of the biosphere. Seas and oceans, rivers and lakes, swamps and groundwater, artificial reservoirs, and permafrost and glaciers, gases and vapors, all water objects being in all three states (gaseous, liquid or solid) belong to the hydrosphere.

The importance of the cycle

The importance of the water cycle in nature is very high, since through this process there is interconnection and full functioning of the atmosphere, hydrosphere, biosphere and lithosphere. Water is the source of life, giving all living things a chance to exist. It carries essential elements throughout the Earth and ensures the full functioning of all organisms.

During the warm season and under the influence of sunlight, water turns into vapor, converting to its second state (gaseous). The liquid that enters the air as steam is fresh water, so the waters of the world ocean are called the “fresh water factory”. As it rises higher, the vapor meets cold air currents, from which they transform it into clouds. Often the evaporated liquid returns to the ocean as precipitation.

Scientists have introduced the concept of the “Great Circle of Water in Nature”, some call this process the World Circle. The idea is this: the liquid collects over the waters of the ocean as precipitation, after which some of it moves to the continents. There, the precipitation falls to the ground and is returned to the world’s oceans through runoff water. This is how water is converted from salty to fresh water and vice versa. A kind of “delivery” of water can be carried out in the presence of such processes as evaporation, condensation, precipitation, and water runoff. Let’s inspect each stage of the water cycle in nature:

  • Evaporation - this process is the conversion of water from a liquid state to a gaseous state. This occurs when the liquid is heated, after which it rises into the air as vapor (evaporation). We find this process every day on the surfaces of rivers and oceans, seas and lakes, because of human or animal sweating. Water evaporates constantly, but you can only see it when it is warm.
  • Condensation is a unique process that causes vapor to turn back into liquid. When it comes in contact with cold air currents, the vapor releases heat and then converts to a liquid. We can see the result of the process as dew, fog and clouds.
  • Precipitation - colliding with each other and undergoing condensation processes, the water droplets in the clouds become heavier and fall to the ground or water. Because of their high velocity, they don’t have time to evaporate, so we often see precipitation as rain, snow, or hail.
  • Water runoff - Once on the ground, they absorb some precipitation into the soil, some goes into the sea, and some nourishes plants and trees. The rest of the liquid accumulates and is delivered to the waters of the world’s oceans by runoff.

Together, the above steps make up the natural water cycle. The state of the fluid is constantly changing, and heat energy is released and absorbed. Humans and animals also take part in such a complex process by absorbing water. The negative impact of humanity is caused by the development of various spheres of industry, the creation of dams, reservoirs, and the destruction of forests, drainage and irrigation of land.

There are also small cycles of water in nature: continental and oceanic. The essence of the latter process is evaporation, condensation, and precipitation directly into the ocean. A similar process can take place on the surface of the earth, which is commonly referred to as the continental small water cycle. Either way, all precipitation, no matter where it falls, is bound to return to ocean waters.

Since water can be liquid, solid, and gaseous, the rate of movement depends on its aggregate state.

Types of the water cycle

Conventionally, we can call three types of the water cycle:

  • The world cycle. A large vapor forms over the world’s oceans. They carry it upward by air currents to the continent where it falls as rain or snow. Then it returns to the oceans through rivers and groundwater.
  • Small. Here steam builds up over the ocean and precipitates right into it.
  • Continental. They form this circulation just inside the continent. Water from the land and inland reservoirs evaporates into the atmosphere, and then after a while returns to the land as rain and snow.

Thus, the water cycle is a process by which water changes state, is purified, saturated with new substances. The cycle allows all forms of life to function. Because water is constantly in motion, it covers the entire surface of the planet.