Different Techniques for Providing Fresh Water to Arid Regions of the World - Research Paper Example

Arid Areas and Water Provision 0 Introduction Water covers most of the earth surface in the form of freshwater and saltwater in oceans and seas. The total area covered by water is approximately 70% of the surface that can be translated to about 326 million trillion gallons of water (Wheather & Li, 2006). According to Wescoat and Vhite (2000), about 96% of the total water available is held in oceans and seas. This water is saline and not available for direct use. The remaining four percent is found mainly in streams, rivers, lakes and groundwater and forms the available for use portion. The water is however in a constant water cycle; vapor evaporates from land, it condenses in the air to form clouds, then it rains, the rainwater flows back to the ocean. With the increase in population and industrial growth, the demand for water is increasing day by day. According to Lenton and Muller (2009), around 780 million people do not have access to safe drinking water currently. They further state that 47% of the world’s population will be facing a serious water crisis by the year 2030 if proper measures are not put in place to conserve water. An arid area is defined as a region that is extremely dry and has little or no vegetation (Walton 2000). The main factors that affect aridity are temperature, evaporation rate and rainfall. Walton (2000) further states most arid areas receive less than 250 mm/10 in rainfall per year. This report will explore the various ways in which water can be made accumulated and made available for human use in arid areas. Information will be gathered from various texts and online sources. The report will also recommend the most appropriate method for water provision. 2.0 Desalination According to Viessman and Welty (1985), desalination is a process in which salt and other minerals are removed from water to make it usable. Most desalination plants employ distillation to clean out the salt and mineral components present in water. In some systems, they use electro dialysis. Use of these water purification methods on large quantities of water is expensive therefore this method is used only as the last resort to provide clean water from saline sources. However, due to the growth in technology, a new method was discovered to filter the water. In this method, sea water is heated and forced through membranes that trap the salt and minerals. This method is more efficient than the other two especially if it is located near a power plant that uses water to cool the generating units (Moltgen & Kabat 2010). 2.1 Advantages Around 97% of water found on earth is saline water. By employing this method, there is a high chance that a lot of water will be made available for human use. For instance, there is a plant in Texas (El Paso desalination plant) that produces around 27.5 million gallons of water per day (Walton, 2000). Another is the Hadera plant in Israel that produces approximately 91.9 gallons of water per day. This is a much greater production that cannot be achieved through the other means. Desalination offers a reliable alternative solution to shield water users from the effects of climate change that is facilitated by increasing global temperatures, increase in population and dwindling supply from groundwater (Hooja, 2009). It is also a convenient way of providing water for arid areas since they require large quantities of water for domestic use and irrigation. 2.2 Disadvantages Desalination just like other processes produces waste which must be disposed. To make the water fit for human use, chemicals such as chlorine, hydrogen peroxide and hydrochloric acid are added into the water. When the chemicals become weak, they are dumped. These chemicals somehow are transferred into the ocean where they endanger aquatic life (Hooja, 2009). The other byproduct of the process; brine, also poses an environmental drawback. 2.3 Feasibility This method is reliable and most convenient way to supply water to arid areas. With enough finances and close proximity to a water body, it offers an uninterruptable source of water for the areas. For instance, this method is used in Hegev desert in Israel to irrigate the desert and also for domestic use. 3.0 Rainwater Harvesting Rainwater harvesting is the collecting and storing of rainwater for human use. This water is collected before it gets to the aquifer (Wheather & Li 2006). In most cases, the water is directed from roofs to constructed tanks or collected in containers for domestic use. 3.1 Advantages Rainwater harvesting is a simple and low cost model for collecting, storing and retrieving water (Viessman & Welty, 1985). Rainwater harvesting systems are also environmental friendly and have low running costs. This method can also be used to supply water in areas where there is water rationing or during emergencies i.e. the main water supply channel is faulty. Rainwater is also soft thereof suitable for domestic use especially washing. 3.2 Disadvantages Rainfall is seasonal: therefore, it cannot be depended on as a reliable source of water. This also necessitates the construction of large storage tanks that are costly. Collected water can also get contaminated by bird droppings found on gutter structures. Furthermore, if the catchment areas are not constructed well and cleaned, they may form a hub for algae growth. This may subsequently have effects on the quality of the water. Regular cleaning of the water system is required and it is costly. 3.3 Feasibility This method is most suitable in areas which receive high rainfall throughout the year or if there are dry spells, they don’t last for over five months (Wheather & Sharma 2002). If efficient conservation measures are implemented, the water may be used for a long duration of time. This also remains as the easiest way to get water. 4.0 Wastewater Recycling Wastewater recycling is the process by which wastewater i.e. sewage is treated with chemicals to remove solids and impurities. The recycled water is then used to recharge groundwater aquifers or for irrigation (Mays 2009). The main aim of recycling water is for water conservation and to ensure there is water sustainability. 4.1 Advantages According to Mays (2009), use of reclaimed water especially for non-potable uses helps to conserve potable water that is then used for other uses. The water from this process is also rich in nutrients such as nitrogen, phosphorous and oxygen thereby making it suitable for use in irrigation. Reclamation of wastewater also helps to conserve the environment since the sewage is recycled before it harms the environment. 4.2 Disadvantages Recycling water requires special plants to be built for the process. The construction of these plants and the pipes to transport the water cost a lot in addition to the chemicals used in this process. Recycled water could also pose some health risks if taken as drinking water since it may contain chemical traces. 4.3 Feasibility This method is most suitable for irrigating arid areas. Even though the water may not be safe for domestic use, the food from the irrigated farms may be useful while proper water is sought from somewhere else. This method will also help to conserve potable water that is rare to find in arid areas. 5.0 Recommendation Among these methods, the desalination and wastewater methods are the most appropriate methods to supply water to arid areas. Rainwater may not be available in some arid areas therefore it cannot be recommended as a reliable method for supplying water in arid areas. Desalination may be implemented to provide water for domestic use while wastewater recycling may be used to supply water for irrigation. 6.0 Conclusion Water supply is crucial in arid areas due to the conditions there but it is subject to availability of funds since they all come at a cost. However, all the three methods are eligible to supply water in dry areas depending on local conditions. List of References Hooja, R 2009, Administration of Desert and Drought – Prone Arid Areas, HCM Rajasthan Institute of Public Administration, New Delhi. Kounduri, P 2008. Water Management in Arid and Semi-Arid Regions: Interdisciplinary Perspectives, Edward Elgar Publishing, New York. Lenton, R & Muller, M 2009, Water Resources Management in Practice: Better Water management for Development, MPG Books Ltd, London. Mays, L 2009, Integrated Urban Water Management: Arid and Semi-Arid regions, Taylor & Francis, New York. Moltgen, J & Kabat, P 2010. Adaptive and Integrated Water Management: Coping with Complexity and Uncertainty, Springer, New York Stephenson, D & Chaoka , T 2004, Water Resources of Arid Areas, Taylor & Francis, Garborone Viessman, W & Welty, C 1985, Water Management: Technology and Institutions, Harper & Row, New York. Walton, K 2000, The Arid Zone, Transaction Books, New York. Wescoat, J & Vhite, G 2000, Water for Life: Water Management and Environmental Policy, Cambridge University Press, New York Wheather, H & Li, X 2006, Groundwater Modeling in Arid and Semi-Arid areas, Cambridge University Press, London. Wheather, H & Sharma, K 2002, Hydrological Modeling in Arid and Semi-Arid Areas, Cambridge University Press. Read More