首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
Greater efficiency in water use is needed to meet the growing demands of a changing world. The per capita water usage has be
Greater efficiency in water use is needed to meet the growing demands of a changing world. The per capita water usage has be
admin
2020-08-17
77
问题
Greater efficiency in water use is needed to meet the growing demands of a changing world.
The per capita water usage has been on an upward trend for many years. As countries industrialize and their citizens become more and more prosperous, their individual water usage increase rapidly. Annual per capita water withdrawals in the USA, for example, are about 1, 700 cubic metres, four times the level in China and 50 times the level in Ethiopia. In the 21st century, the world’s limited supply of renewable freshwater is trying to meet the 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.
Agriculture consumes about 70% of the world’s freshwater, so improvements in irrigation can make the greatest impact. At present, the 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, the industry sector is the second biggest user of water and, in terms of value added per litre used, is 60 times more productive than agriculture. However, some industrial processes use vast amounts of water. For example, production of 1kg of aluminium might require 1,500 litres 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 the industrial uses of water.
In rich countries, water consumption has gradually been slowed down by price increase 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. The Japanese industry, for example, now recycles more than 75% of the processed water. However, industrial water consumption is continuing to increase sharply in the developing countries like India. With domestic and agricultural demands also increasing, the capacity of water supply systems is also under growing strain.
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 the 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 subsidized 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 1970s, coupled with concerns that supplies were running low, led to new energy conservation measures all over the world. It was realized 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.
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 1990s 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 are merely flushed away and discharged into rivers or the seas. The modern approach, however, is to see the 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 of the farm irrigation there. There are other examples in cities, such as St Petersburg, Florida, where all municipal water is recycled back into domestic systems.
Another way of conserving water resource involves better management of the environment generally. Interference with the ecosystem can have a severe effect on both the local rainfall patterns and the water run-off. Forest clearings associated with India’s Kabini Dam project reduced the 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 act as a sponge which absorb rainfall, both in the plants and around. Removal of the vegetation means that the rainfall runs off the top of the land, accelerating erosion instead of being gradually fed into the soil to renew groundwater.
Global warming is bound to affect the 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 the seawater penetration of groundwater. Other countries will experience changes in rainfall which could have a major impact on the 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.
What impact does global warming have on water crisis?
选项
答案
It will impact the rainfall patterns-rainfall zones will shift northwards,adding to the water deficit in Africa,the Middle East and the Mediterranean.
解析
最后一段第一句指出,全球变暖会影响降雨模式。最后一句讲到,降雨区域会北移,这将导致非洲、中东、地中海地区的水资源短缺。
转载请注明原文地址:https://kaotiyun.com/show/Hwra777K
本试题收录于:
翻译硕士(翻译硕士英语)题库专业硕士分类
0
翻译硕士(翻译硕士英语)
专业硕士
相关试题推荐
中国国际进口博览会(ChinaInternationalImportExpo,简称CIIE)。2017年5月,习近平主席在“一带一路”国际合作【R31】________上宣布,中国将从2018年起举办中国国际进口博览会。2018年
PopstarstodayenjoyastyleoflivingwhichwasoncetheprerogativeonlyofRoyalty.Wherevertheygo,peopleturnoutinthe
AlthoughSimpsonwasingeniousat______toappearinnovativeandspontaneous,beneaththeruseheremaineduninspiredandrigid
Shewaitedatthegate,herhands______beforeher.
I’mafraidtheresultofthecomingelectionisa______conclusion.
Thephysicalshapeandcoloringofmanyanimalsaretheresultofgradual______toparticularcircumstances.
It’snothingnewthatEnglishuseisontherisearoundtheworld,especiallyinbusinesscircles.ThisalsohappensinFrance,
Ourfootballcoachhasworkedhardto______ateamspiritintotheplayers.
______today’sdigitalrevolutionservesahostofpracticalconcerns,suchascommunicatingandaccessinginformationmorequick
Thefootballmatchwas________becauseoftheheavyrain.
随机试题
关于封闭式基金的交易,以下说法正确的是( )。
金葡菌肺炎患儿突然出现呼吸困难、憋气。应首先考虑
A.暴露怀疑偏倚B.选择偏倚C.测量偏倚D.随机测量误差偏倚E.混杂偏倚
患者东某,发热头痛,汗出恶风,鼻鸣干呕,苔薄白,脉浮缓。治宜选用()
结构跨度为2m~8m的钢筋混凝土现浇板的底模及其支架,当设计无具体要求时,混凝土强度达到()时方可拆模。
陈先生打算5年后买房,现在开始准备首付款,他每个月从收入中拿出5000元进行投资,预期投资收益率为7%,那么到了购房时,陈先生能够准备的首付款为()元。
若认为职位供需比介于1~2之间的专业,其供需结构较为稳定,则图中满足这一条件的专业个数为( )。下列说法错误的是( )。
调查表明,在当今85-90岁的人中,极少数人是左撇子。社会学家研究认为,这是因为在80年前如果小孩用左手吃饭或写字就要挨打,所以被迫用右手。这项调查能够加强的论断是( )。
取消高中阶段的文理分科,应当慎行。只有当绝大部分学校的课程、师资等教育资源丰富起来时,我国高中教育阶段实施真正意义上的学分制教育才具有坚实的发展基础;只有当包括高考和高校录取制度改革在内的教育整体改革逐步完成时,全面取消文理分科方可说水到渠成。全
Thepopularnotionthatolderpeopleneedlesssleepthanyoungeradultsisamyth,scientistsreportedonawell-acknowledgedp
最新回复
(
0
)