The time you take a glass of water to take a sip, just wonder of the actual source of this water, it can be the same water that must be used by the first humans, wooly mammoths or the earlier rulers. It is surprising to know that water is going through the recycling process by our planet Earth for over 4 billion years.
The ongoing cycle of water by which we all surrounded can be in form lakes, rivers, oceans, glaciers, land, and atmosphere. This is the continuous system of water and is known as ‘water cycle‘ or ‘hydrologic or hydrological cycle‘. The water cycle can be processed in three forms, that can be either solid (ice), liquid (water), or gas (vapor).
It can be predicted by the name that the path of water cycle must be simple and circular, consisting of few stages such as evaporation, condensation and precipitation. However in reality it is more complexed one as still the path of this cycle in under research and many studies are still going to understood this complicated pathway.
This study will be helpful in gaining more knowledge globally, for understanding the weather forecast, climate change, ecosystem changes, and other water resources and their utility.
The water has three forms, that can be either solid (ice), liquid (water), or gas (vapor). In the whole process the water changes its phase from one form to other, but the number of particles remains constant.
The main motive to understand the water cycle is to know that how the water evaporates from the Earth’s surface, rises and collected into the atmosphere, cools and condensed into snow or rain, and then again falls back to the Earth’s surface.
In this article we will shed light on the water cycle and the steps involved in it, with a brief description on each.
Stages of Water or Hydrological Cycle
There are numerous steps involved in the water cycle, of which the significant one are the evaporation, transpiration, condensation, precipitation, and run off. As said earlier that the total amount of water in the cycle remains almost constant, but its distribution throughout the process keeps on changing.
1. Evaporation
The Sun is the natural and powerful source of energy, even responsible for the process of evaporation that happens on Earth. Evaporation takes place when the water molecule at the Earth surface are ready to rise into the air. With this ongoing process, the water molecules with the high kinetic energy forms the water vapor clouds. Usually evaporation occurs below the boiling point of water.
There is other term related to evaporation is the evapotranspiration, this actually takes place in plant through the leaves. So the evaporation through the leaves is the evapotranspiration and is considered to be the largest percentage contributor of water to the atmosphere.
2. Sublimation
Sublimation is the process where the ice or snow directly convert into water vapor without changing into water. It happens due to the low humidity and dry winds. Sublimation usually occurs at the mountain peaks, where the air pressure is at low side. The sublimation requires less energy than the evaporation process, and therefore the low air pressure supports the ice or snow to directly change into the water vapour. On our planet Earth, the main source for sublimation is the ice sheets present at the poles.
3. Condensation
Due to the low temperatures at high altitudes the water vapor that has been collected cools down. Gradually, these water vapor converts into tiny droplets of water and ice and gather together to form clouds.
4. Precipitation
The condensation of water vapors into water droplets is not possible without the presence of dust or other impurities, even at zero degree Celsius or above. So, the water vapors get itself adhere to the surface of the particles. When these droplets gets collected, it falls out from the clouds and even to the surface of the ground. This process is known as ‘rainfall or precipitation. However, in case of snow fall or hail the cold weather or extremely low air pressure is responsible to cause the effect.
5. Infiltration
Furthermore, the rain water is been absorbed by the ground through the infiltration process. The intensity of absorption depends on the material on which the water droplets has fallen. For instance, the soil will retain more water, as compared to the rocks. The absorbed ground water will either gets connected to the rivers or streams, but it may also sink deeper to form aquifers.
6. Run Off
In case if the water does not get sink to form aquifers, it follows the track of gravity and flows down the sides of hills and mountains and finally meeting the rivers. This process is known as runoff. In the colder parts, it is seen that the icecaps froms naturally, especially when the when the amount of snowfall is higher the rate of sublimation. The largest icecaps are present on the poles of the Earth.
Bottom Line
The noticeable thing is that we all know that it does not rain equally in all parts of the world or snowfall is seen everywhere, and therefore the measurement of cycling of water in and out of the atmosphere becomes more crucial to understand. Hence out of the four steps of the water cycle, the term ‘precipitation’ becomes one of the most vital constituent of the water cycle, and is helpful to gather the information about the water that falls on the surface of the Earth, which connects the land, atmosphere and ocean and the whole cycle continues.
