IELTS READING – THE WATER CRISIS S25GT5

IELTS READING

THE WATER CRISIS

Greater efficiency in water use is needed to meet the growing demands of a changing world

A. Per capita water usage has been on an upward trend for many years. As countries industrialize and their citizens become more prosperous, their individual water usage increases rapidly. Annual per capita water withdrawals in the USA, for example, are about 1,700 cubic meters, four times the level in China and fifty times the level in Ethiopia. In the 21st century, the world’s limited supply of renewable fresh water is having to meet demands of both larger total population and increased per capita consumption. The only practicable ways to resolve this problem in the longer term are economic pricing in conjunction with conservation measures.

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B. Agriculture consumes about 70% of the world’s fresh water, so improvements in irrigation can make the greatest impact. At present, average efficiency in the use of irrigated water in agriculture may be as low as 50%. Simple changes could improve the rate substantially, though it is unrealistic to expect very high levels of water-use efficiency in many developing countries, faced as they are with a chronic lack of capital and a largely untrained rural workforce. After agriculture, industry is the second biggest user of water and, in terms of value added per liter used, is sixty times more productive than agriculture. However, some industrial processes use vast amounts of water. For example, production of 1 kg of aluminium might require 1,500 liters of water. Paper production too is often very water-intensive. Though new processes have greatly reduced consumption, there is still plenty of room for big savings in industrial uses of water.

C. In rich countries, water consumption has gradually been slowed down by price increases and the use of modern technology and recycling. In the USA, industrial production has risen fourfold since 1950, while water consumption has fallen by more than a third. Japan and Germany have similarly improved their use of water in manufacturing processes. Japanese industry, for example, now recycles more than 75% of process water. However, industrial water consumption is continuing to increase sharply in developing countries. With domestic and agricultural demands also increasing, the capacity of water supply systems is under growing strain.

D. Many experts believe that the best way to counter this trend is to impose water charges based on the real cost of supplies. This would provide a powerful incentive for consumers to introduce water-saving processes and recycling. Few governments charge realistic prices for water, especially to farmers. Even in rich California, farmers get water for less than a tenth of the cost of supply. In many developing countries there is virtually no charge for irrigation water, while energy prices are heavily subsidize too (which means that farmers can afford to run water pumps day and night). Water, which was once regarded as a free gift from heaven, is becoming a commodity which must be bought and sold on the open market just like oil. In the oil industry, the price increases which hit the market in the 1970’s, coupled with concerns that supplies were running low, led to new energy conservation measures all over the world. It was realize that investing in new sources was a far more costly option than improving efficiency of use. A similar emphasis on conservation will be the best and cheapest option for bridging the gap between water supply and demand.

E. One way to cut back on water consumption is simply to prevent leaks. It is estimated that in some of the biggest cities of the Third World, more than half of the water entering the system is lost through leaks in pipes, dripping taps and broken installations. Even in the UK, losses were estimated at 25% in the early 1990’s because of the failure to maintain the antiquated water supply infrastructure. In addition, huge quantities of water are consumed because used water from sewage pipes, storm drains and factories is merely flushed away and discharged into rivers or the sea. The modern approach, however, is to see used water as a resource which can be put to good use – either in irrigation or, after careful treatment, as recycled domestic water. Israel, for instance, has spent heavily on used water treatment. Soon, treated, recycled water will account for most farm irrigation there. There are other examples in cities such as St Petersburg, Florida, where all municipal water is recycled back into domestic systems.

F. Another way of conserving water resources involves better management of the environment generally. Interference with the ecosystem can have a severe effect on both local rainfall patterns and water run-off. Forest clearings associated with India’s Kabini dam project reduced local rainfall by 25%, a phenomenon observed in various other parts of the world where large-scale deforestation has taken place. Grass and other vegetation acts as a sponge which absorbs rainfall both in the plants and in the ground. Removal of the vegetation means that rainfall runs off the top of the land, accelerating erosion instead of being gradually fed into the soil to renew ground water.

G. Global warming is bound to affect rainfall patterns, though there is considerable disagreement about its precise effects. But it is likely that, as sea levels rise, countries in low-lying coastal areas will be hit by seawater penetration of ground water. Other countries will experience changes in rainfall which could have a major impact on agricultural yield – either for better or for worse. In broad terms, it is thought that rainfall zones will shift northwards, adding to the water deficit in Africa, the Middle East and the Mediterranean – a grim prospect indeed.

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IELTS READING – Lack of sleep S26GT5

IELTS READING

Lack of sleep

Section A

It is estimated that the average man or woman needs between seven-and-a-half and eight hours’ sleep a night. Some can manage on a lot less. Baroness Thatcher, for example, was reported to be able to get by on four hours’ sleep a night when she was Prime Minister of Britain. Dr Jill Wilkinson, senior lecturer in psychology at Surrey University and co-author of ‘Psychology in Counselling and Therapeutic Practice’, states that healthy individuals sleeping less than five hours or even as little as two hours in every 24 hours are rare, but represent a sizeable minority.

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Section B

The latest beliefs are that the main purposes of sleep are to enable the body to rest and replenish, allowing time for repairs to take place and for tissue to be regenerated. One supporting piece of evidence for this rest-and-repair theory is that production of the growth hormone somatotropin, which helps tissue to regenerate, peaks while we are asleep. Lack of sleep, however, can compromise the immune system, muddle thinking, cause depression, promote anxiety and encourage irritability.

Section C

Researchers in San Diego deprived a group of men of sleep between 1am and 5am on just one night, and found that levels of their bodies’ natural defences against viral infections had fallen significantly when measured the following morning. ‘Sleep is essential for our physical and emotional well-being and there are few aspects of daily living that are not disrupted by the lack of it’, says Professor William Regelson of Virginia University, a specialist in insomnia. ‘Because it can seriously undermine the functioning of the immune system, sufferers are vulnerable to infection.’

Section D

For many people, lack of sleep is rarely a matter of choice. Some have problems getting to sleep, others with staying asleep until the morning. Despite popular belief that sleep is one long event, research shows that, in an average night, there are five stages of sleep and four cycles, during which the sequence of stages is repeated.

In the first light phase, the heart rate and blood pressure go down and the muscles relax. In the next two stages, sleep gets progressively deeper. In stage four, usually reached after an hour, the slumber is so deep that, if awoken, the sleeper would be confused and disorientated. It is in this phase that sleep-walking can occur, with an average episode lasting no more than 15 minutes.

In the fifth stage, the rapid eye movement (REM) stage, the heartbeat quickly gets back to normal levels, brain activity accelerates to daytime heights and above and the eyes move constantly beneath closed lids as if the sleeper is looking at something. During this stage, the body is almost paralysed. This REM phase is also the time when we dream.

Section E

Sleeping patterns change with age, which is why many people over 60 develop insomnia. In America, that age group consumes almost half the sleep medication on the market. One theory for the age-related change is that it is due to hormonal changes. The temperature General Training: Reading and Writing rise occurs at daybreak in the young, but at three or four in the morning in the elderly. Age aside, it is estimated that roughly one in three people suffer some kind of sleep disturbance. Causes can be anything from pregnancy and stress to alcohol and heart disease. Smoking is a known handicap to sleep, with one survey showing that ex-smokers got to sleep in 18 minutes rather than their earlier average of 52 minutes.

Section F

Apart from self-help therapy such as regular exercise, there are psychological treatments, including relaxation training and therapy aimed at getting rid of pre-sleep worries and anxieties. There is also sleep reduction therapy, where the aim is to improve sleep quality by strictly regulating the time people go to bed and when they get up. Medication is regarded by many as a last resort and often takes the form of sleeping pills, normally benzodiazepines, which are minor tranquillisers.

Section G

Professor Regelson advocates the use of melatonin for treating sleep disorders. Melatonin is a naturally secreted hormone, located in the pineal gland deep inside the brain. The main function of the hormone is to control the body’s biological clock, so we know when to sleep and when to wake. The gland detects light reaching it through the eye; when there is no light, it secretes the melatonin into the bloodstream, lowering the body temperature and helping to induce sleep. Melatonin pills contain a synthetic version of the hormone and are commonly used for jet lag as well as for sleep disturbance. John Nicholls, sales manager of one of America’s largest health food shops, claims that sales of the pill have increased dramatically. He explains that it is sold in capsules, tablets, lozenges and mixed with herbs. It is not effective for all insomniacs, but many users have weaned themselves off sleeping tablets as a result of its application.

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