How important is this cycle to Earth? Essay

The hydrologic cycle or the water cycle is basically the incessant and continuous flow and movement of water, beneath, above, and on the Earth’s surface (Encyclopedia of Earth, 2007). It involves a number of processes such as the changing of water into its different states, namely, vapor, ice, and liquid, as it goes through the different stages of the cycle (Encyclopedia of the Earth, 2007). In addition, since it is a cycle, it does not have a beginning or an end. Basically, in broader terms, the water cycle is a conceptual model of the movement and the storage of water between the lithosphere, hydrosphere, biosphere, and atmosphere (Encyclopedia of the Earth, 2007). Water is stored in the earth’s major reservoirs such as oceans, rivers, lakes, glaciers, soils, snowfields, groundwater and even the atmosphere (Encyclopedia of the Earth, 2007). As mentioned above, water goes through different processes. These processes can be generally divided into 5 parts: condensation, evaporation, precipitation, infiltration, and runoff (Encyclopedia of the Earth, 2007). The first process is condensation which occurs when the water vapor transforms into water droplets in the air thereby producing clouds. As these clouds condense further, they hold more moisture. When it can no longer contain the moisture, they release through precipitation, which can be in the form of rain, snow, hail, sleet, and fog drip (Encyclopedia of the Earth, 2007). The water that drops back down to the earth then seeps into the ground through a process called infiltration. On the other hand, if precipitation occurs much faster than it can infiltrate the ground, it then becomes a process called runoff. Basically, runoff water remains on the surface and then subsequently flows to large bodies of water such as oceans, rivers, lakes, and seas among others (Encyclopedia of the Earth, 2007). Finally as infiltration and runoff occur simultaneously, evaporation, which is a process driven by the sun, also occurs. Evaporation is the transformation of liquid water into water vapor. This process is largely aided by sunlight as it increases the temperature in lakes, oceans, and seas (Encyclopedia of the Earth, 2007). As the water in these bodies of water heats, its molecules are released and are turned into gas. This warm air then rises into the atmosphere and then becomes the water vapor involved in the condensation process, which repeats the hydrologic cycle (Encyclopedia of the Earth, 2007). However, other processes also occur within these five processes. One example is sublimation which is the direct transformation of solid water, such as ice and snow, into water vapor without passing through the liquid state (Encyclopedia of the Earth, 2007). Basically, the hydrologic cycle is highly important to the Earth as it provides life to its inhabitants. The cycle basically moves the water through a continuous and constant flow and keeps it fresh for different uses. For example, if water that evaporates does not fall back to the earth through precipitation in the form of rain, then the world’s crops and vegetation would die out and ultimately result in shortages in food. In addition, the oceans and the seas would dry out and kill all marine life. There will also be shortages in water supply as people highly depend on the water that comes from oceans, seas, and lakes. The water shortage would then result in massive thirst and dehydration, which would ultimately kill all human life. On the other hand, if the water does not rise to the air through evaporation after a typhoon, cyclone, or a massive storm, then most parts of the Earth would remain flooded and eventually, all the lands would be submerged underwater. In short, the hydrologic cycle generally keeps the flow and storage of water in a natural state of balance. If this cycle ceases function properly, then all life on Earth would eventually be wiped out due to thirst, hunger, and drought. References Encyclopedia of the Earth. (2007). Hydrologic Cycle. Retrieved July 9, 2008 from http://www. eoearth. org/article/Hydrologic_cycle.