The Importance of Water Cycle & 6 Stages of Water Cycle

It is rightly said that “If there is magic on this planet, it is contained in water” because water is the driving force of all nature.

Life cannot survive on this beautiful planet Earth in the absence of water. It exists in three phases, i.e., solid, liquid and gas. Water is responsible for tying major and essential parts of the Earth’s climate system together which includes air, clouds, ocean, lakes, vegetation, snowpack, and glaciers. It binds these parts of the climate system with the help of a cycle known as the ‘water cycle’ which also reveals the importance of the water cycle.

What is Meant by ‘Water Cycle’?

Water plays a significant role in sustaining life and nature on planet Earth. The water on Earth is always in some sort of movement in the form of a cycle which is known as the ‘water cycle’ or ‘hydrologic cycle’. During this cycle, the water keeps moving on, above, and below the surface of the Earth. Water continuously changes to various states i.e., liquid, vapor, and ice. This change regarding the state of water is continuously taking place in the blink of an eye for millions of years.

The water cycle is a complex system that includes many different procedures. Water, from its liquid state, evaporates into water vapors and then condenses in order to form clouds. From clouds, the water again precipitates back to earth in the form of snow and rain. After coming to the liquid form again on Earth, the water then flows on lands into the ground by infiltration and percolation and through groundwater.

The groundwater then moves into the plants by plant uptake and then evaporates into the atmosphere through the process of transpiration which recognizes the importance of the water cycle. The water in its solid form i.e., ice and snow directly turn into the form of gas by the procedure of sublimation. On the other hand, the opposite of this process can also take place if water vapors turn to solid form i.e., deposition.

This process of movement of water through the atmosphere in various phases is known as transportation.

Stages of Water Cycle

The entire process and “importance” of the water cycle can be classified into few essential steps, briefly described above, are further discussed in detail below;

• Evaporation
• Condensation
• Precipitation
• Sublimation
• Transpiration
• Infiltration

These steps can be described as:

Step#1: Evaporation

It is the first step of the water cycle that initiates the entire process. At this stage, heat from the sun comes to force in order to turn the water on the surface of lakes and oceans into vapors or steam. This stage of the water cycle depicts that how water from the main bodies of earth transform to another state and move into the atmosphere through hydrosphere which also endorses the importance of water cycle.

Step#2: Condensation

In this step, the water vapors present in the air transform to a liquid state. This process takes place when the water vapors reach very high altitudes where owing to the cold temperature, these vapors of water turn to extremely tiny droplets of ice and water. Later, these small particles of water and ice combine together to form clouds. Due to this reason, condensation is considered a very substantial step of the water cycle.

Step#3: Precipitation

This step is responsible for releasing water from clouds in the form of rain, snow, or hail. It only happens when the clouds contain condensed water to such an extent that they cannot hold it anymore. Due to the heaviness of clouds, waterfalls down to earth. This step is important because it is the main stage where water cycle returns its water to Earth.

Step#4: Sublimation

After precipitation, comes the step of sublimation. It is the stage where precipitation comes back to planet Earth in the form of ice or snow and completes the water cycle. It only takes place if ice or snow does not melt and skips the liquid phase completely. It rather directly converts to the state of gas and evaporates. This step is comparatively really slow.

Step#5: Transpiration

This step involves the process in which water is soaked up by the roots of plants and evaporates from the leaves. In this stage, the water moves through the plant and later, evaporates from its aerial parts like leaves, flowers, and stems. Like other living beings, water is substantial for plants as well. However, only a small amount of water taken by the roots contributes to ensuring growth and metabolism in the plant. While the remaining 97% to 99.5% of the water is lost by transpiration.

Step#6: Infiltration

Infiltration is the process by which water present on the ground is soaked into the soil. The infiltration capacity can be defined as the maximum rate of infiltration. The infiltration capacity tends to decrease as the moisture of the soil from the surface layers increases. In case the precipitation rate exceeds the infiltration rate, due to excess rainwater, meltwater, and groundwater, etc., the flow of water will increase tremendously unless there is some physical barrier.

Global Water Distribution

The natural and water resources of planet Earth make it an ideal place to live for living beings. Mother Earth consists of 71% of water and hence Earth is a watery place due to which people would understand the importance of the water cycle on earth as important as would oxygen. A number of research studies conclude that the surface of Earth consists of about 71% of water while oceans of the planet contain about 96.5% of the total Earth’s water.

Apart from being present on Earth, water is also present in the air in the form of water vapors. Not only this, but water is also present in lakes, rivers, glaciers, icecaps, ground, aquifers as well as in the body of living beings.

The bar chart illustrates that almost all of the water present on planet Earth is saline and is present in oceans. Moreover, only a small percentage of the water available on the planet can be used for drinking and sustaining the life of all living beings including humans, plants as well as animals.

The first bar in the chart explains that only 2.5% of the water on Earth is ‘freshwater’ that can help living beings to survive. The middle bar explains the breakdown of freshwater. Almost all the freshwater is sealed in the ice and land. Only around 1.2% of water or a little above that is the surface water which is used to serve the needs of human, animal, and plant life.

Similarly, the third bar on the extreme right side of the chart shows the different segments of surface freshwater. Most of the percentage of this water is locked up in ice while 20.9% of it is found in lakes. Rivers constitute around 0.49% of the surface freshwater. It is pertinent that although only a small amount of fresh water is present in rivers yet, human beings get most of the water from these sources to meet their needs.

Importance of Water Cycle for Earth and Environment

The importance of the water cycle or hydrologic cycle cannot be denied because it enables water to reach animals, plants as well as humans. Along with catering to the water needs, it also moves other things with its flow e.g., pathogens, nutrients, and sediment to and from the aquatic ecosystems. On the other hand, another significant aspect regarding the importance of the water cycle is that it also plays a key role in benefitting living beings by purifying water. As the water evaporates, the pollutants in it are left behind. It also purifies the aquatic life thus meeting its needs because saltwater also needs to be within a certain pH level and saline ranges.

Importance of Water Cycle for Humans

Just like other living beings, the life of human beings is also entirely dependent upon water and its availability. Water constitutes up to 60% – 70% of all living matter. Human beings cannot survive in the unavailability of water for more than a week. Therefore, the importance of the water cycle cannot be denied because it ensures the distribution of water all over the surface of Earth.

Conclusion

In simple terms, the water cycle can be defined as a path that is followed by water as it moves around the planet in different states. Water is a blessing that need to be utilized carefully and wisely. The water cycle ensures the availability of water for all living organisms thus it is extremely important.

It plays a key role in regulating the weather pattern of our planet as well. The importance of the water cycle can be further understood by the simple fact that if water does not recycle naturally, the living beings on planet earth would run out of clean water which is really essential for life and its sustainability.