Monday, October 14, 2019

Providing Fresh Water To Arid Regions Environmental Sciences Essay

Providing Fresh Water To Arid Regions Environmental Sciences Essay From 1950-2000, there was a huge rise in the demand of the water (Smallwood, 2010). The reason for this massive increase in demand can be due to the massive increase in the worlds population towards the later years of the century. Between the years 1940 to 1960 worlds population was roughly around 2500 millions of people (U.N, 2004). This number increased to 6000 millions of people in year 2000 according to United Nations projections in 2004 (ibid). In order fulfil this huge demand of water different countries in the world started using large scale water management techniques. These techniques were very useful at the beginning however these large scale water management techniques are now considered to be in decline (Smallwood, 2010). The focus is now on the small scale water management techniques, however these small scale techniques such as traditional techniques are sometimes not considered to be sufficient enough (ibid). The arid and semi arid regions are those parts of the where there is very little or no rainfall. These areas are largely in central and south eastern parts of Asia, Africa and some parts of America. Pakistan is a developing country in south eastern region of Asia. Pakistan is a semi arid country with the problem of water management in the country. Therefore as an example of semi arid region this report will focus on the feasibility techniques for managing fresh water in Pakistan. Furthermore, this report will look at the dams as large scale water management technique and water desalination and use of ground water as small scale water management techniques. Pakistan 2.1 Background of water management through the use of large dams in Pakistan As a developing country Pakistans economy is mainly dependent on agriculture. Nearly one quarter of Pakistans GDP is contributed by agriculture sector (Ali, 2004). In order for agricultural sector to flourish Pakistan needs to manage water very carefully. A great amount of water for irrigation comes from 5 main rivers of Pakistan (Ali, 2004). These rivers are Indus, Ravi, Jhelum, Sutlej and river Chenab (ibid). Canal water is generated from these five rivers (ibid). This canal system is the largest canal system in the world (ibid). In addition to this there are 2 main dams build in order to manage water more properly. These dams are Mangla and Tarbela dams. Among these dams there are many other small dams build in order manage water for agriculture and electricity generation purposes. The researchers have however argued that these dams are not sufficient enough for Pakistans power and agriculture needs and there is a need to build more dams in order to manage water more sufficiently. 2.2 Current situation Dams can provide cheap electricity and dams can also help in scenarios of natural disaster. Pakistan is currently facing an electricity shortfall of 3000 to 6000 megawatts (Khan.2010). Furthermore recent floods in Pakistan have destroyed thousands of villages and hundreds of cities. According to United Nations floods in July 2010 has affected more than 20 million people in Pakistan. These floods have not only affected the people but floods have also destroyed the crops, which were the main source of income for the people in Pakistan. The arguments have again taken a rise that a controversial KalaBagh dam should be built and if that dam would have been there this flood would not have affected as much it has affected now. The KalaBagh dam is the largest proposed dam to be built in the northern areas of Pakistan. However due to being controversial the work on this has not been started. 2.3 Kalabagh dam, a controversial proposed large dam Kalabagh Dam Project proposed to be located near Islamabad on Indus River (Alvi et.al.N.D). The proposed dam is a multi-purpose project, it would have a live storage capacity of 6.1 million acre feet (ibid).it will fill the capacity loss in reservoirs, it would make contribute very much to irrigation supplies not only for new projects but provide additional water which was agreed by the provinces under Water Apportionment Accord (WAA) of 1991 (ibid). Furthermore, it would add a large amount of cheap hydropower to the National Grid through its 2400 MW (Ultimate 3600 MW) installed power (ibid). This can solve the energy crises of Pakistan and the electricity shortfall can be finished. However this project is opposed by three provinces of Pakistan. Other than Punjab, Sindh, Baluchistan and Khyber Pakhtunkhuwa all are against the project of Kalabagh dam. According to the Sindhi point of view Kalabagh dam would turn sindh into desert (Alvi et.al.N.D). There would be no additional water to fill Kalabagh reservoir (ibid). However recent floods in Pakistan prove that there are enough surpluses of water. Sea water intrusion in Indus estuary would accentuate (ibid). Building of Kala bagh dam will destroy the mangrove forests, which are already threatened (ibid). KalaBagh dam would affect the fish production and water supplies in the southern areas of Pakistan (ibid). It is feared that historic flooding of Peshawar Valley including Nowshera town would be aggravated in the event of recurrence of 1929 record flood (Alvi et.al.N.D). Drainages of surrounding area of Mardan, Pabbi and Swabi plains would be adversely affected by the reservoir thus creating water logging and salinity (ibid). Operation of Mardan SCARP would be adversely affected (ibid). Fertile land would be submerged (ibid). Large number of people would be displaced (ibid). The claims that are mentioned above are the fears of the provinces and it remains to be seen that these claims do really have any reality behind them.Other than the above controversial reasons the Kalabagh dam is a mega project. In other words the Kalabagh dam is considered to be in the large scale water management technique. As it is argued by the Smallwood (2010) that the world is generally moving from using the large scale water management techniques towards the small scale water management techniques. The reason for this is that large scale water management techniques have many disadvantages. When the water is stored on a large scale there is a high risk of water born diseases (Smallwood.2010). Large dams are the combine resources so it is difficult manage the water as everybody would require more water (ibid). In addition to this, large dams causes large amount of displacements of the people (Ibid). Water desalination and small dams used as small scale fresh water management by other arid or semi arid countries Due to the exploitation of natural sources of water, as the water demand has increased, there is a great stress on alternate sources of fresh water (Fritzman et.al, 2006). The sea water can be used to fulfil the demands of the water (ibid). The water is desalinated through thermal technology (ibid). Through this technology the salt is evaporated from the water to make it able for daily use (ibid). The Middle East areas of the world are the main user of the water desalination technology (ibid). These areas are arid and it has a great demand of fresh water (ibid). In order to fulfil the water demands the thermal water desalination technology is being used (ibid). The arid and semi arid regions of Europe are also using the water desalination technology (ibid). The greatest example is the Spain which has the largest water desalination capacity (ibid). This demand of the desalinated water will grow further with Middle East being the greatest user of this technology (ibid). This is due to the rapid increase in the population of Middle Eastern areas (ibid). The Asia will become the rapid growing market of water desalination as there is large increase in population and conventional water resources are becoming insufficient to fulfil the demand of the water (ibid). The water desalination can fulfil the water demands very easily however the cost of installing the water desalination plants are high. However as compared to large dams the cost of water desalination plant is low, meaning water desalination can provide water very cheaply. Through water desalination the water can only be provided to the areas which are near to the sea (Smallwood, 2010). In order to provide fresh water to the areas which are away from the sea and the areas are arid small scale dams can be built to fulfil the demand of the fresh water. A small scale or micro dam if it is designed properly can provide many benefits to the areas near the dam (Ersado, 2005). The micro dams can provide water for irrigation, water for cattle and might even provide water for fishing purposes (ibid). In the areas where there is scarcity of water, usually in developing countries the micro dams can provide water for domestic purposes (ibid). The micro dams are less expensive as compared to large dams and these dams are less controversial. These dams however have many side effects (Ersado, 2005). The standing water can be the source of malaria (ibid). Moreover the standing water provides a good environment for disease transmission (ibid). Conclusion As it argued by Smallwood (2010) that the world is now moving away from the large scale water management. The developed nations such as U.S.A have stressed upon small scale water management techniques (Smallwood, 2010). The arid areas such as Middle East is using water desalination method in order fulfil the demand of fresh water (Fritzman et.al, 2006). The developing countries can also use their costal line in order to fulfil the demand of fresh water. For example Pakistan has a long costal line starting from south of Sindh till the end of south of Baluchistan. This costal line can be used for water desalination and it can fulfil the demand of fresh water of the southern arid areas of Pakistan. As it already predicted by Fritzman et.al (2006) that the water desalination method would be the fastest growing method of providing fresh water, the developing nations such as Pakistan should consider this method and fulfil its water demands.

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