The water cycle serves to maintain the balance of the earth's ecosystems, and to provide fresh and pure water to all living beings, thanks to the re-circulation of this vital liquid.
Water is present on earth in three physical states: solid (snow and ice), liquid (oceans, lakes, rivers and seas), and gaseous (water vapor).
All forms of water participate in this cycle, which takes place consequently and which is essential for the development of life on planet Earth.
Life without water would not be possible. The reuse of this valuable and limited resource is only feasible thanks to the water cycle.
What is the water cycle?
The water cycle is a process that occurs due to the interactions of chemical, biological and geographical reactions in the environment.
Thus, the water that is on the surface in a liquid state tends to evaporate, thanks to the action of sunlight.
Then the water vapor condenses, forms clouds and gives rise to precipitation. In turn, these precipitations seep into the earth, ending the cycle and promoting its re-activation.
Benefits of the Water Cycle
- Water is a non-renewable resource. Without the water cycle, this vital liquid could not be reused, and consequently it would be depleted in an accelerated way until it disappears from planet Earth.
Thanks to the water cycle, it is purified due to changes in state, and the re-circulation process makes its use again suitable.
- The hydrological cycle induces the circulation of water through different ecosystems, favoring the balance of the environment.
- Through this cycle, water is always available to supply the hydration, nutrition and subsistence needs of plants, animals and human beings, originating and conserving life.
- Rainfall and surface water runoff have a direct impact on the cycle of other elements present in nature, such as nitrogen, carbon, sulfur and phosphorus.
Phases of the Water Cycle
The water cycle has six main phases:
1) Evaporation: surface water evaporates and, as it changes state, its weight decreases and rises to the atmosphere.
2) Condensation: water vapor condenses in the atmosphere. Subsequently, hundreds of thousands of drops make up the clouds.
3) Precipitation: the drops get bigger and bigger and descend towards the surface in the form of rain, snow or hail.
4) Infiltration: part of the water is used directly by plants, animals and humans, the other portion of the rainwater passes through the ground and becomes groundwater.
5) Runoff: water travels across the surface, below the ground, almost imperceptibly, depending on the type of soil.
6) Underground circulation: runoff water continues to slide under the surface until it is absorbed by tree roots, or flows into nearby bodies of water, restarting the cycle.
References
- Water cycle (2013). Recovered from: ecologiahoy.com
- Water cycle (nd). Santiago de Chile, Chile. Recovered from: profesorenlinea.cl
- Definition of the Water Cycle (2013). Dictionary Definition ABC. San Salvador, El Salvador. Recovered from: definicionabc.com
- The Water cycle (nd). © 2017 Khan Academy. Recovered from: es.khanacademy.org
- Importance of the water cycle (nd). Recovered from: importa.org
- Wikipedia, The Free Encyclopedia (2017). Hydrological Cycle. Recovered from: es.wikipedia.org