VOA标准英语2012--Scientists Say Africa Sits on Huge Reservoir of Water

Scientists Say Africa Sits on Huge Reservoir of Water

Scientists say an estimated 300 million people in Africa do not have access to safe drinking water and with climate change making rainfall less predictable, their plight¹ is even more precarious².

So research into a vast reservoir of groundwater beneath the continent is meaningful.

Richard Taylor, a hydrologist at University College London, said there is reason to be optimistic.

“What we’re saying here really is that there are quite considerable groundwater resources in Africa that might help to regulate soil moisture and therefore food security,” said Taylor.

The study estimates that there are 0.66 million cubic kilometers of groundwater beneath the continent, an estimated 100 times more than what’s available on the surface.

Maps produced by the British Geological Survey and University College London show the spots where groundwater is most plentiful³ - in Libya, Algeria, Egypt and Sudan.

The study suggests that countries currently designated as "water scarce" could be sitting on groundwater supplies tens of meters deep.

Currently only 5 percent of African agriculture uses irrigation. Scientists predict the demand for water will grow rapidly with the population.

Inevitably⁴ there are fears of over-extraction. But the small-scale nature of much African agriculture could prevent a so-called "tragedy of the commons," Taylor said.

“The actual low productivity aquifers⁶, there’s kind of a silver lining⁷ to them being low productivity. It means that an individual largely affects themselves. If they over-pump the aquifer⁵, the geology is such that the impacts of that over-pumping are not translated very far, and they are really only doing themselves injury,” said Taylor.

Aid agencies are warning of an imminent⁸ food crisis in parts of Niger and Mali. Could boreholes drilled through to the groundwater solve problems like this? Not necessarily on their own, according to Taylor.

“Part of us putting numbers to it, quantifying the groundwater resources that are available in many locations, is to try to improve the explicit⁹ consideration of groundwater as one of many strategies to improve food production and resilience to drought,” he said.

The authors say this is no sure solution - but suggest aquifers could provide a more reliable source of water than the notoriously unpredictable rains. 

1 plight   

n.困境，境况，誓约，艰难；vt.宣誓，保证，约定

参考例句：

• The leader was much concerned over the plight of the refugees.那位领袖对难民的困境很担忧。
• She was in a most helpless plight.她真不知如何是好。

2 precarious   

adj.不安定的，靠不住的；根据不足的

参考例句：

• Our financial situation had become precarious.我们的财务状况已变得不稳定了。
• He earned a precarious living as an artist.作为一个艺术家，他过得是朝不保夕的生活。

3 plentiful   

adj.富裕的，丰富的

参考例句：

• Their family has a plentiful harvest this year.他们家今年又丰收了。
• Rainfall is plentiful in the area.这个地区雨量充足。

4 inevitably   

adv.不可避免地；必然发生地

参考例句：

• In the way you go on,you are inevitably coming apart.照你们这样下去，毫无疑问是会散伙的。
• Technological changes will inevitably lead to unemployment.技术变革必然会导致失业。

5 aquifer   

n.含水土层

参考例句：

• An aquifer is a water-bearing rock stratum such as sandstone and chalk.地下蓄水层是一些有水的岩石层，如沙岩和白垩岩。
• The wine region's first water came from an ancient aquifer.用来灌溉这个地区葡萄园的第一批水来自古老的地下蓄水层。

6 aquifers   

n.地下蓄水层，砂石含水层( aquifer的名词复数 )

参考例句：

• And in Africa, the aquifers barely recharge at all. 非洲的地下水开采以后几乎得不到补充。 来自时文部分
• Aquifers have water contents over 30%. 含水层的水含过30％。 来自辞典例句

7 lining   

n.衬里，衬料

参考例句：

• The lining of my coat is torn.我的外套衬里破了。
• Moss makes an attractive lining to wire baskets.用苔藓垫在铁丝篮里很漂亮。

8 imminent   

adj.即将发生的，临近的，逼近的

参考例句：

• The black clounds show that a storm is imminent.乌云预示暴风雨即将来临。
• The country is in imminent danger.国难当头。

9 explicit   

adj.详述的，明确的；坦率的；显然的

参考例句：

• She was quite explicit about why she left.她对自己离去的原因直言不讳。
• He avoids the explicit answer to us.他避免给我们明确的回答。