Urban Water Cycle - Essay Example

Task: Water Cycle and Urban Water Cycle Natural Water Cycle The water within the earth is always in constant motion. This motion involves several processes that form the water cycle. Apparently, water cycle is the description of the continuous water movement within, below or above the earth’s surface. It is called hydrological cycle. This movement of water involves a change in the physical state between vapor, ice and liquid. The main driving force responsible for the circulation of water is heat. Heat is exchanged within resultant temperature changes. The sun is the main source of heat that enhances the water cycle. As it heats the ocean and seawaters, evaporation takes place leading to loss of water to the air. This water meets the rising air currents that take it up through vapor into the environment. While in the atmosphere, the cooler temperatures condense the vapor to form clouds (Kalman and Sjonger 17). The air currents circulate the water vapor around the earth. As this movement takes place, the particles in the cloud keep on colliding with each other and grow. Eventually, the vapor rises to the upper most part of the atmosphere before it begins to fall in layers of precipitation. Some precipitation falls in form of snow, sleet or hails that accumulate to form glaciers and ice caps. Snow and ice sometimes sublime to form water vapor directly. A higher percentage of precipitation falls back into seas, oceans and land as rains. Those that fall on land flow either through surface runoffs back into rivers, lakes, oceans and seas or sink into the ground to form groundwater. Groundwater helps to replenish aquifers. Through openings in the surface of the land, some ground water rises up as freshwater in springs. These natural ways allows water to circulate the globe. Water then flows into rivers and oceans from where evaporation takes place (Morgan 31). Urban Water Cycle The circulation of water assumes an almost similar process as the natural water cycle within an urban setting. However, the urban water cycle is massively under the influence of human interventions. The urban water cycle is simply the description of the distance that a drop of water travels from the point of collection for urban use to the point of return to the natural water cycle. Most traditional sources of water in urban centers are diminishing especially through availability and supply. This requires increased investments in integrated water management systems to improve sustainability measures (Tong 21). The availability of reliable fresh water supply in urban centers is an essential requirement to all human beings. Traditionally, every village in many civilizations had water wells that allowed residents to fetch water for domestic and agricultural use. The collection of water from the well was done through buckets and urns. Thereafter, the water was manually carried to houses for use. Later on, the Romans considered the use of canals to pipe in water from the wells into some specific buildings for use. They also built drains to convey wastewaters from the buildings. Due to this design, diseases and epidemics such as cholera and typhoid as the rest of the world did not attack the Romans. This idea by the Romans formed the genesis for urban water circulation. The Industrial Revolution period was a good turning point as people learned new methodologies of supplying water in large quantities to emerging cities and towns. Moreover, the improvement of scientific and medical knowledge in modern times has helped facilitate the supply and provision of clean and safe water to cities and towns. It has also helped address the problems of wastewater disposal. These kinds of developments have resulted into the creation of manmade water cycle, otherwise known as urban water cycle. The urban water cycle involves the collection of water from its naturally occurring or flowing location, its treatment, use, disposal, the sewerage treatment and releasing of the treated sewerage back into the natural water cycle (Hlavinek, Kukharchyk and Marsalek 45). Most urban centers receive their supply of water from a definite water entity such as a river, lake or a dam. The land area that surrounds the water source is its catchment. The level of cleanliness of a catchment area determines the water quality of the dam or river. A town that uses a dam or several dams as water reservoirs will receive water from rivers. In this regard, the state of the river will determine the water quality that enters the dam. The dam is the storage point for the water from rivers. It is normally built adjacent to a river to block a section of the flowing water and store it. It is from the dam that the urban population receive reliable water supply for their use. Although the water in the dam might look clear, it is not fit for human consumption yet. This is because it contains pollen, soil particles and dust. These particles contain viruses, bacteria together with several other microorganisms that can be harmful to human health. To remove these microorganisms, the water from the dam is first processed in a water treatment plant prior to its use. The water goes through some specific stages and steps at the treatment plant. Such stages include pre treatment, flocculation, filtration and chemical dosing. At the pre treatment level, a polymer called coagulant and alum is added to the water. The substances help to capture the solid particles that provide host to bacteria and viruses. The water free of the particles remains less turbid and clean. At the flocculation level, there is the removal of solid particle from the water. Mixing and circulation occurs for the solid particles captured in the pre treatment step to float on top in the form of froth. At the filtration level, the water is pumped through filters to get rid of the remaining particles. Finally, there is the addition of chlorine to get rid of the remaining microorganisms or germs, if any at the chemical dosing stage. This stage also involves the addition of fluorine for teeth protection and the adjustment of the pH level of the water. After the above stages of treatment, the bulk main pipes supply carries the treated water to reservoirs allowing its distribution into smaller pipes into households. The reservoirs help the water stored to adjust with the changing demands. It also assists in the management of the pressure from users so that it flows to taps at expected speeds. Reservoirs can be either above or below the ground. The reservoirs supply water into homes through the service lines than branch from the mains pipe. After use at home, the water goes down the drain from where it enters the network of wastewater. The wastewater then flows into the sewerage system. The sewerage system consists of a network of pipes that conveys sewage off businesses and the household. These pipes relay the sewage to a sewage treatment plant for treatment and safe recycle. The sewage, being mostly water will flow in the sewage system by the force of gravity. The treatment of the sewage involves the summation of complex processes that aims to get rid of toxic and poisonous substances. The solid particles then are separated from the particles of water. Cleaning and releasing of the remaining water is into the natural cycle occurs. Several sewage treatment approaches in the world exist. The natural water cycle is where water flows through an existing system known as the water cycle. In this cycle, water continuously moves between the land, atmosphere and the oceans (Karamouz, Moridi and Nazif 34). Conclusion The urban water cycle involves the movement of water across several channels. The quality of water determines the health of humans that use it from the catchment area. As a result, care is fundamental when safeguarding and conserving catchment areas. This involves avoiding such activities as farming, deforestation and the use of pesticides on farms. This is because the chemicals finally find their way into the dam. Additionally, the sewer waters need mandatory treatments before release into the natural water cycles for the good health of the environment. Works Cited Hlavinek, Petr et al. Integrated Urban Water Resources Management. Dordrecht: Springer, 2006. Print. Kalman, Bobbie and Rebecca Sjonger. The Water Cycle. New York: Crabtree Publishing Company, 2006. Print. Karamouz, Mohammad, Ali Moridi and Sara Nazif. Urban Water Engineering and Management. Boca Raton, Fla.: CRC PressINC, 2010. Print. Morgan, Sally. QR code for The Water Cycle. New York: The Rosen Publishing Group, 2009. Print. Tong, T H. Application of a Total Urban Water Cycle Model to Develop Urban Water Management Strategies for Tel Aviv, Israel, Water Balance and Energy Consequences. Delft: Unesco-IHE, 2009. Print. Read More