The planet is abundant with water and this vast reserve undergoes a cyclical process. From oceans to mountains, water undergoes several transformations in the process and the scale where the water cycle can occur can extend to several hundreds of miles. The fact that the process is called “water cycle” suggests that water is always on the move, in a manner of speaking.
One stage in the water cycle is called the precipitation stage. In this process, water falls back to the earth “usually in the form of rain from the nimbus clouds (Senior, et al. p. 1306).
”However, rain is not only the form of precipitating water as it also includes the snow fall that we experience during the cold winter season, the hail that we see fall from the sky during thunderstorms as well as tornadoes, and even the thick blanket of fog that we see during the early hours of the morning and just before the night sets in on several occasions. All of these examples are forms of water in the precipitation stage of the water cycle.After the precipitation stage, water is then stored in the many different land and water forms in the earth. For instance, the rain that fell from the sky is probably collected in shallow ponds, lakes, rivers and other bodies of water. A significant volume of this precipitation is collected in the largest possible body of water in the world—oceans.
Moreover, the precipitated water can also be collected high in the mountains or in the plains of the rural farms and other land forms.Even on the ground surface of the earth regardless of whether it is mud, clay or any other type of soil, water can also be collected. As far as the water stored in the mountains is concerned, the tendency for it is either to continue moving as a runoff in the form of streams or falls on the surface of the mountains or to penetrate the ground. The water can also stay in the leaves of trees and other plants for a short duration of time. There is also the possibility for the water to solidify in the freezing temperatures in the higher regions of the mountains.After a certain stretch of time, these frozen waters in the form of mountain ice will eventually melt and return to its liquid state, running down the mountain sides in the form of small streams or perhaps big waterfalls.
The water from rainfall can also gather in manmade structures such as dams and open wells. In general, the water that precipitates in the form of rain falls back to the earth and is stored and transported to many different areas. The journey of water, in a manner of speaking, does not end to the point where it is stored in numerous bodies of water and land.On the other hand, it can be said that the part where water is stored in these areas is the part where water begins to take another transformation. This water transformation is called evaporation—the stage wherein water turns into gas form from its liquid state. Evaporation takes place through “the combination of several factors such as the heat of the sun and the wind (Woo, p.
216). ” The heat coming from the sun eventually reaches the waters in the ocean, on the ground and on top of the mountains. This same heat loosens the molecules of water and heats them as well, thereby turning liquid water into gas.With its warm state, the molecules of water separate which results to less weight, enabling it to rise to the atmosphere. The rising of these molecules of water can be further hastened through several environmental factors such as the rising air caused by “fronts” and cyclones.
A common manifestation of evaporation is the occurrence of steam; it is hot and the visible gas rising in the air is water in its gas form. Multiply that image by the thousands if not millions and you get an image of the evaporation process taking place in many different parts of the world.However, it is not always the case that the evaporating water is visible to the naked eye. For instance, a small pool of water in your front lawn during the heat of the day may eventually dry-up a few hours later without your knowing. The wet clothes hanging in your backyard in the morning may become dry in the afternoon.
More unseen and yet too common situations include the drying-up of leaves that were once soaked in rainwater, or the rising and falling of the water levels in lakes and ponds. These are just some common examples of water evaporating from the earth to the sky.After evaporating to the sky, water begins to turn into clouds, the process commonly referred to as condensation. It is the process whereby water that evaporated turns into more visible liquid form such as dark nimbus clouds or the thin and high-altitude cirrus clouds. To say that water has condensed is to say that the water molecules have become closer from what was once a separate state. The reason behind this is that the cooler temperature in the higher regions of the atmosphere tends to cool the warm water vapor, thereby causing these “cooled” vapors to start forming droplets of clouds (Ripl, p.
928).In the higher regions of the atmosphere, the temperature can reach below zero degrees Celsius that the droplets of clouds that reach that part eventually form into ice crystals. It is often the case that these ice crystals high above the atmosphere form cirrus clouds. In any case, water vapor that forms into clouds of small water droplets and even ice crystals are stored in the atmosphere. Once these water droplets and ice crystals are heavy enough that they can no longer stay high in the atmosphere, they eventually fall back to the earth.It is important to note that this next stage where water droplets and ice crystals fall back to the earth occurs in different forms.
The most common example is rainfall, a natural phenomenon that illustrates how water that formed as clouds returns to the ground. In the case of ice crystals, they can fall back to the earth as snow or hail. Depending on where the process has occurred, the ice crystals may also melt into their liquid state even before they reach the ground. For instance, cirrus clouds may eventually precipitate in the form of falling snow several kilometers from the ground.
However, the falling snow from the cirrus clouds may melt while still falling in the atmosphere due to the heat coming from the sun. In the end, rain may fall on the ground instead of snow. In cooler regions of the world, however, snowfall can be experienced due to the lower temperature in the atmosphere closer to the ground where the falling precipitation from cirrus clouds would have to travel before touching the ground. But regardless of whether it is rain or snow, these two things are both manifestations of precipitation, which brings us back to the stage in the water cycle which we first identified.
It is likewise important to note that the precipitation stage is not necessarily the first stage in the water cycle. In fact, there is no such thing as a first stage in the water cycle precisely because the nature of the process is cyclical—it has neither a beginning nor an end. At any rate, the fact that water undergoes a cycle should be a useful piece of information for human civilization—as it has been indeed—because water is such a precious commodity that we truly ought to understand its nature.
