-
(单词翻译:双击或拖选)
Science and Technology Flood defences Dambusterbusters
科技 防洪减灾 堤坝除险，以水御水
Some clever, new ways of stopping rivers flooding
防止河水泛滥的绝妙新方法
THE destruction of New Orleans by Hurricane Katrina in 2005 showed the importance of keeping levees—the artificial banks that contain the flow of partly canalised rivers—in tip-top condition.
2005年的卡特利娜飓风摧毁了新奥尔良。这场惨剧提示我们部分渠化的河流其人造大坝即使在洪峰到来，河水漫坝的情况下也要挺住而不出现垮塌是多么重要。
In practice, though, that is hard.
然而，实际上这很难做到。
Levees fail for many reasons, not all of them associated with violent storms, and there are so many of them (100,000 miles-worth in America alone) that keeping an eye on all of them is an almost impossible task.
导致堤坝垮塌的原因很多，并非全都是狂风暴雨所致。而且堤坝数量众多（仅在美国就有十万英里的在用堤坝），难以对所有的堤坝状况都进行密切监视。
It is good, therefore, to have a backup plan to block up unexpected holes before they can cause too much damage.
因此，事先储备预案极为重要，一旦堤坝出现未曾预料的缺口时能够及时予以封堵，以防造成更大灾难。
一旦堤坝出现裂口，传统的做法是向缺口抛掷沙袋和石块。
Such bags, though, are heavy and unwieldy—particularly if they have to be filled far from the breach and then carried there.
然而这些沙袋死沉，难以搬运。如果不得不在离裂口较远的地方灌装沙袋再运过去的话，这项工作就难上加难。
William Laska of the Science and Technology Directorate at America's Department of Homeland Security has therefore sought out alternatives.
威廉?拉斯卡在美国国土安全部所属的工程科技处工作。
He has found several technologies that have a common theme: they all use water itself to help stem the flood.
他找到了解决这一难题的办法,这些方案有一个共同点：以水御水。
这些新发明的装置中体积最大是设计用来堵塞宽深堤坝裂口的。
The Portable Lightweight Ubiquitous Gasket (PLUG) is a sausage-shaped balloon made of polyester and PVC, and fitted with motorised pumps.
这种装置叫做"便携式通用轻型堵漏包"（其英文缩略语为PLUG，正好有塞子的意思）。
When dropped into a river (usually by helicopter), PLUG's pumps switch on automatically and begin forcing water into the balloon through a valve.
它是由聚酯纤维和聚氯乙烯制作的圆柱形气球，并安装了发动机带动的水泵。把这个装置投入河中（一般使用直升机），水泵就自动开始工作，通过一个阀门把河水注入气球。
The air thus displaced is expelled through a second valve until the device is 80% full, at which point the pumps shut themselves down.
河水不断注入，球内的空气通过另一组阀门被挤出。就这样直到水充满了80%的球体后水泵就自动停了下来。
Filled thus far, PLUG is still buoyant and will float wherever the current carries it.
灌了这么些水PLUG仍然可以浮于水面，随河水任意漂流。
If it has been dropped in the right place, that will be towards the breach it is designed to fill.
如果投放的位置恰当，它就会漂到堤坝的裂口处。
And there, if all goes well, it will stick—blocking the hole in a manner suitable to its rather contrived3 acronym4.
在这里如果一切顺利的话，就像这个装置有点蹩脚的的英文首字母缩略语道出的，它就会像一个塞子一样堵住裂口。
Prevention, however, is always better than cure, and the second of Mr Laska's devices is designed to stop levees being breached5 in the first place.
常言说治病不如防病，对待堤坝亦然。拉斯卡先生发明的第二种装置就是用于事先防止堤坝出现垮塌。
这种装置的全称是"泥土坝便置保护装置"，其英文首字母的缩略语REPEL也正好有"防御"的意思。
REPEL is made of the same material as PLUG, but instead of being thrown into the water and carried to its destination by the current, it is laid out flat on a levee that is in danger of being overtopped and thus eroded8 by the river it is supposed to contain.
它与第一种装置使用同样材料制作，但不是要把它投入河中由水流带到裂口处。一旦河水猛涨漫过堤坝就会对泥土坝造成冲蚀，危及堤坝的安全。此时可以把REPEL铺在堤坝顶上保护堤坝。
In normal circumstances merely placing a layer of protective material on top of a levee in this way would not do much good.
一般来说如果只是这样在堤坝顶部铺一层类似的保护材料在漫坝时不会起到什么作用。
The force of the water would quickly wash it away.
水流的力量会很快将它们冲掉。
However, REPEL has a series of tubes that sit on top of it and can be pumped full of water in a manner similar to that employed by PLUG.
而ERPEL在其上部装上了一系列的粗管，可以如第一种装置一样往这些粗管里灌水。
The weight of these tubes holds the protective layer in place, while the gaps between the tubes permit the overspill to escape.
这些装满水的管子的重量足以固定住这些保护层，漫出堤坝的河水可以在粗管间溢过。
Some flooding from that overspill results—but not as much as if the spill were allowed to erode7 and destroy the levee itself.
这样虽然有一些河水漫出堤坝，但造成的损失会远远小于由于土坝在水流侵蚀下而垮塌产生的后果。
Yet simply halting floodwaters and preventing short-term damage is not enough.
然而只是堵住了洪水防止了眼前的灾难并不完美。
Neither PLUG nor REPEL can be used permanently9.
PLUG与REPEL都是应急设施。
拉斯卡先生还有第三套装置，其首字母缩略语是REHAB，又正好有"重建"之意。工程师们可以用它对堤坝进行永久性的修复。
The Rapidly Emplaced Hydraulic11 Arch Barrier, made of the same material as the other two devices, can be put in place around a plugged breach to keep it sealed and dry once the PLUG has been removed.
该装置的全称叫做"便置式拱形折流坝"。它与前两种装置采用相同材料制作，可以围住一个被暂时封堵住的堤坝裂口，使之与河水隔开。此时就可以将PLUG这个塞子撤掉，晾干堤坝裂口处的泥土。
First, the arch is filled with air and floated to the desired location.
首先将这个拱坝注入空气使它能够漂到指定的位置。
Then, once it is in place, it is partly flooded and allowed to sink to the riverbed around the breach, making a tight seal.
一旦到位，就向拱坝内灌水使它沉到裂口周围的河床上，形成了一道严密的围堰。
That done, a second set of pumps evacuates12 the gap between the arch and the PLUG, allowing workers access to the site.
这些工作完成后，再调用一组水泵将拱坝与堵塞间的水全部抽干，堤坝抢修工人们就可以进入现场进行堤坝的修复作业了。
Not only is installing REHAB easier and faster than building a conventional temporary dam, it is also less wasteful13.
设置一道"重建"拱坝与常规的方法建临时围堰相比不仅省时、省工，而且还省钱。
A conventional temporary structure is demolished14 after use.
常规的临时围堰在完工后还需要拆除。
REHAB can simply be floated away and reused-it will have rehabilitated15 itself, in other words.
这种"重建"拱坝用完后只需充气排水就可浮起拖走重新使用，这也就是说，这种拱坝是可重复使用的。
点击
收听单词发音
收听单词发音 |
1
breach
|
|
| n.违反，不履行；破裂；vt.冲破，攻破 | |
参考例句： |
|
|
|
|
2
breaches
|
|
| 破坏( breach的名词复数 )； 破裂； 缺口； 违背 | |
参考例句： |
|
|
|
|
3
contrived
|
|
| adj.不自然的，做作的；虚构的 | |
参考例句： |
|
|
|
|
4
acronym
|
|
| n.首字母简略词，简称 | |
参考例句： |
|
|
|
|
5
breached
|
|
| 攻破( breach的现在分词 )； 破坏，违反 | |
参考例句： |
|
|
|
|
6
repel
|
|
| v.击退，抵制，拒绝，排斥 | |
参考例句： |
|
|
|
|
7
erode
|
|
| v.侵蚀，腐蚀，使...减少、减弱或消失 | |
参考例句： |
|
|
|
|
8
eroded
|
|
| adj. 被侵蚀的，有蚀痕的 动词erode的过去式和过去分词形式 | |
参考例句： |
|
|
|
|
9
permanently
|
|
| adv.永恒地，永久地，固定不变地 | |
参考例句： |
|
|
|
|
10
acronyms
|
|
| n.首字母缩略词( acronym的名词复数 ) | |
参考例句： |
|
|
|
|
11
hydraulic
|
|
| adj.水力的；水压的，液压的；水力学的 | |
参考例句： |
|
|
|
|
12
evacuates
|
|
| 撤离，疏散( evacuate的第三人称单数 )； 排空（胃肠），排泄（粪便）； （从危险的地方）撤出，搬出，撤空 | |
参考例句： |
|
|
|
|
13
wasteful
|
|
| adj.（造成）浪费的，挥霍的 | |
参考例句： |
|
|
|
|
14
demolished
|
|
| v.摧毁( demolish的过去式和过去分词 )；推翻；拆毁（尤指大建筑物）；吃光 | |
参考例句： |
|
|
|
|
15
rehabilitated
|
|
| 改造（罪犯等）( rehabilitate的过去式和过去分词 )； 使恢复正常生活； 使恢复原状； 修复 | |
参考例句： |
|
|
|
购买
在百度中搜索