The water cycle, also known as the hydrological cycle, is the constant cycle of water between oceans, atmosphere, and land. As a natural phenomenon, the water cycle is very important for sustaining life on our planet. Nevertheless, the water cycle can be considered rather difficult to understand. Consequently, in this paper, we will explain the water cycle and illustrate the steps involved.
Water Cycle: Definition
The water cycle is a natural phenomenon that involves the constant movement of water between oceans, atmosphere, and land of the Earth in all three phases: liquid, solid (ice), and gaseous (vapor). The water cycle is initiated by heating the Earth using solar energy which causes evaporation. Once in the atmosphere, the water becomes colder and turns into drops resulting in precipitation.
Evaporation: First Stage of the Water Cycle
As one can see from the definition above, the first stage of the water cycle includes evaporation of water. Evaporation occurs when enough heat causes water molecules to disperse in the atmosphere. Thus, evaporation is responsible for moving water from oceans and lakes into the atmosphere.
Condensation: Formation of Clouds
The following step in the water cycle involves the process of condensation. Condensation occurs when evaporation results in cold water vapor turning into water drops which form clouds. Condensation takes place when the air is saturated and reaches dew point which is the temperature level when air cannot hold additional water molecules. It should be noted that clouds may include supercooled drops which are liquid water molecules below freezing temperature.
Precipitation: Main Process in the Water Cycle
The moment of water drops becoming too heavy and falling to the ground constitutes the process of precipitation and is the main part of the water cycle. The types of precipitation include:
* rain – small drops of liquid water;
* snow – snowflakes made of ice crystals;
* sleet – frozen raindrops; and
* hail – ice balls made from water molecules in the clouds.
Infiltration and Runoff: Consequences of Precipitation
When precipitation falls to the surface of the earth, it may either run off or infiltrate underground. Infiltration involves the draining of the precipitated water into underground layers of the soil. The latter process is also called runoff as the precipitated water goes over the surface and gets into rivers and lakes.
Groundwater: Hidden Step in the Water Cycle
Groundwater refers to subsurface water that infiltrates the soil and gets accumulated in underground water-bearing rocks. This part of the water cycle is extremely important for maintaining life on earth as groundwater serves as a buffer during droughts and also provides fresh water. Moreover, groundwater is rechargeable both from runoff and underground water streams.
Importance of Water Cycle
As mentioned above, the water cycle plays a significant role in ensuring the survival of living organisms. Therefore, the importance of the water cycle can be illustrated by such points as:
* regulation of climate and energy budget of the Earth;
* provision of water to ensure drinking, agriculture, and industry; and
* maintaining ecosystems by providing clean water.
How to Study Water Cycle
There are many sources of information to get more details on the water cycle such as:
* videos and documentaries explaining the process;
* books published on the water cycle online/offline;
* websites and blogs providing information on the issue;
* and online communities discussing the water cycle.
