Howard, Mathias & Xin (2010) estimates that about 30 percent of the total world land area comprises of inhabited arid and semi-arid areas. In this regard, Howard, Mathias & Xin (2010) points out that the main impediment social and economic development in these arid and semi-arid areas relates to significant water shortages. This is because sustainable economic development depends significantly on sustainable management of water resources while at the same guaranteeing sustainable supply of the same. According to Koundouri (2006), most arid areas face the problem of fresh water shortage provided by rivers and lakes. In aIDition, arid areas have a limited supply of underground water resources. The problem is worsened further by the fact that limited fresh water in these areas is increasingly becoming salty because of the constant disruption of the aquifers. Furthermore, the demand for water in arid regions is increasing due to the various factors such as population growth, urbanization and vigorous industrialization (Mays 2009). Owing to the fact that arid areas have limited accessibility conventional sources of fresh water, the desalination of seawater and partial ground water sources are the main sources of water supply. Shemang & Chaoka (2004) argues that, in order to guarantee the continuity of life arid regions, there is the need to devise feasible methods that guarantee the supply of fresh water. This essay explores the methods that can be used to ensure the supply of fresh water in arid regions and evaluates their feasibility.
Desalination, sometimes referred to distillation, involves turning the salty sea water into fresh drinking water by removing the salt found in sea water. The National Academy of Sciences (2001) considers desalination as one of the oldest and most popular techniques of water treatment. In this regard, Mays (2009) asserts that desalination is extremely feasible, particularly in guaranteeing the supply of fresh water in arid areas. In aIDition, Mays (2009) points out that desalination is removes most of the drinking water contaminants. As of 2002, there were about 12,500 desalination plants producing about 14 million cubic meters of water on a daily basis. Despite the fact that water production from desalination plants is relatively low with respect to the global daily consumption of freshwater, Shemang & Chaoka (2004) asserts that desalination plants make significant contributions in the supplying freshwater to arid areas. In this regard, Koundouri (2006) stipulates that installing more desalination plants in arid areas would increase the production of fresh water in arid areas; hence, reducing the demand pressure for fresh water in these areas.
A number of countries in arid areas are already using desalination plants to increase their freshwater supply. For instance, countries found in the MiIDle East such as Bahrain, Kuwait, United Arab Emirate, Qatar and Saudi Arabia depend significantly on desalination to supply freshwater to their citizens (Koundouri 2006). According to Koundouri (2006), a number of these countries have reported significant economic growth in the past few decades because desalination increased freshwater supply, which is a crucial requirement for economic development. In aIDition, some regions in the United States lacking natural freshwater sources, such as Florida and California, have successfully deployed desalination to increase their freshwater supply. According to Shemang & Chaoka (2004), California and Florida account for about 6.5% of worlds desalinated water supply. It is imperative to note that Florida and California have reported substantial economic growth and development despite lacking a natural freshwater source; this economic development can be attributed to the use desalination, which provides further evidence regarding the feasibility of using desalination as a potential source of freshwater supply in arid areas (Shemang & Chaoka 2004).
Recycling of Municipal Waste Water
Mays (2009) reveals that sewages often include human waste that can be treated, under a particular specification, to produce freshwater fit for human use. Recycling of wastewater takes place in biological water treatment plants. A case in point is the Durban wastewater recycling plant in South Africa, which purifies about 4000 m3 of wastewater for industrial purposes. Nevertheless, Shemang & Chaoka (2004) points out that the primary challenge for this method of providing water supply involves convincing the public that the water is 100 percent safe and fit for human consumption. Koundouri (2006) asserts that recycling municipal wastewater is both safe and economical when compared to other methods. In this regard, Koundouri (2006) maintains that recycling wastewater does not require enormous financing except during the initial stage of setting up the waste treatment plant.
According to the National Academy of Sciences (2001), there are a number of challenges associated with recycling wastewater, particularly with regard to its implementation and execution decisions, which is worsened by the fact that linking the purified water to the municipal supply system requires infrastructure. Shemang & Chaoka (2004) raise concerns regarding the skills required to ensure that this projects are a success. In aIDition, poor decision-making and management with regard to the process of awarding tenders for projects associated with the construction of these plants are likely to affect their relative success. Nevertheless, it is imperative to note that these are administrative challenges that can be aIDressed, and that this technique has been practically implemented. As a result, it can be argued that this technique is feasible and can help in restoring huge amounts of wastewater for use by both industries and citizens.
Harvesting Ground Water Using Boreholes
Just like other natural resources, surface water is in the verge of diminishing, especially in arid areas. Soon, people in arid regions will run of freshwater supply if they utilize all the surface water that is accessible. Surface water can be harvested from freshwater springs and rivers that can be accessed relatively easily. According to Howard, Mathias & Xin (2010), drilling boreholes is a common practice in arid areas because of the acute water shortage in these regions. There are numerous projects that involve drilling boreholes with the primary objective of harvesting groundwater. The National Academy of Sciences (2001) considers ground water harvesting a viable method because there are no maintenance costs following the initial drilling. In aIDition, the ground water tapped is naturally safe and pure, eliminating any potential treatment costs.
Regardless of their significance in aIDressing the water shortage problem in arid areas, Koundouri (2006) asserts that open boreholes are susceptible to contamination, which can result in the outbreak of waterborne diseases. Nevertheless, there are potential viable solutions to open boreholes such as the use of water purification pills that can purify ground water in just about 24 hours. One more concern regarding the harvesting of ground water is that the tapped water from boreholes is likely to contain salt; however, there are secondary treatment options, such as boiling and chemical treatment, that are relatively cheap to ensure that the water is salt free. It is evident that harvesting ground water is a feasible technique of increasing the supply of freshwater in arid regions since it is relatively cheap to drill and maintain water boreholes. The table below shows a cross comparison of desalination, wastewater treatment and harvesting of ground water.
|Desalination||Wastewater treatment||Harvesting ground water|
|Requires technical knowhow and skills in establishing and maintaining the desalination plant||Requires technical knowhow and skills in establishing and maintaining the sewage treatment plant||Requires technical knowhow and skills only during drilling|
|Maintenance costs of the desalination plant||Maintenance costs of the sewage treatment plan||No maintenance costs|
|Water undergoes treatment||Water undergoes treatment||Water is tapped in a naturally pure state|
This paper has evaluated the feasibility of three different techniques that could be used to provide fresh water to arid regions, which include desalination, recycling waste water and harvesting of ground water. In the wake of increasing demand for freshwater and concerns posed by climate change, governments in arid areas have to recognize the significance of coming with alternatives to increase the freshwater supply. The paper has shown that that desalination, recycling wastewater and harvesting ground water are feasible techniques that can be used to supply freshwater in arid regions. Desalination and wastewater treatment need a lot of technological and skilled labor to implement, which is contrary to the harvesting of ground water using boreholes. A cross comparison shows that all the methods are economically feasible and can guarantee sustainable supply of freshwater in arid regions.
National Academy of Sciences 2001, More Water for Arid Lands: Promising Technologies and Research Opportunities, The Minerva Group, Inc., Honolulu, Hawaii.
Howard, W, Mathias, S & Xin, L 2010, Groundwater Modelling in Arid and Semi-Arid Areas, Cambridge University Press, Cambridge.
Koundouri, P 2006, Water Management in Arid and Semi-arid Regions: Interdisciplinary Perspectives, Edward Elgar Publishing, Cheltenham.
Mays, L 2009, Integrated Urban Water Management: Arid and Semi-Arid Regions: UNESCO-IHP, Taylor & Francis, New York.
Shemang, S & Chaoka, R 2004, Water Resources of Arid Areas: Proceedings of the International Conference on Water Resources of Arid and Semi-Arid Regions of Africa, Garborone, Botswana, 3-6 August 2004, Taylor & Francis, New York.