经济学人85:森林保护 激光雷达探测术

 　　Science and Technology Forest conservation Lidartector

　　科技 森林保护 激光雷达探测术

　　How to tell if countries are cheating on their conservation commitments

　　如何判断一个国家在森林保护承诺上是否有舞弊行为

　　IN AN isolated¹ forest in the Sivalik hills of south-western Nepal, intense sun beats down through the treetops.

　　位于尼泊尔西南部西瓦利克山脉一处偏僻的森林内,毒辣的阳光正从树冠强射而入。

　　A sweaty trek² up a steep, rocky slope leads to a spot where a team of researchers is busy measuring the trees.

　　经过一段汗流浃背的艰难跋涉，登上一处陡峭怪石嶙峋的斜坡,到达一块区域,就可以看到一组研究人员正忙着对树木进行测量。

　　They are working for Forest Resource Assessment³ Nepal, a joint⁴ venture between the Nepalese and Finnish governments.

　　他们是尼泊尔与芬兰政府森林资源评估合资企业的工作人员。

　　Two global-positioning-system devices guide the researchers to their target.

　　凭借两套全球定位系统就可将研究人员带到目的地。

　　Once there, they use tape measures, callipers and a hand-held laser to measure the heights and girths of all the trees within a 500-square-metre plot.

　　到达目标后，在圈定好的500平方米区域内，他们用卷尺，测径规和手持激光设备对所有树木的高度和树围进行测量。

　　These measurements, and each tree's species, are recorded on a clipboard. One plot finished; 959 more to go.

　　测量结果及每棵树的品种都会被记录下来。一块区域测量完成后，他们还要转战其余的959块区域。

　　A classic piece of forestry⁵, then. Boots on the ground. Specimens⁶ duly counted.

　　这是当时的一种传统林艺技术，采用人力进行实地考察，准确测量标本。

　　But this is a study with a twist, for its purpose is to calibrate⁷ a new approach to the subject—one that will gather information by the bucketload without the need to rely on quite so many boots.

　　但一项新的研究将会使现状产生飞跃的转变，其目标是针对该课题开创一种新的测量方法—即无须动用众多的人力物力就可收集到大量所需信息。

　　This new approach uses a technique called lidar.

　　这项新方法采用的技术称之为"激光雷达术"。

　　Like its cousins radar⁸ and sonar, lidar (light detection and ranging), works by broadcasting electromagnetic waves towards a target and then building up a picture from the reflection.

　　与雷达和声纳技术相似，激光雷达（光探测和测距）的工作原理是通过向目标发射电磁波然后根据反射波构建图像。

　　In the case of lidar, the waves are in the form of an infra-red laser beam.

　　拿激光雷达来说，其波形采用的是红外激光束。

　　And in the case of the forests of south-western Nepal, the target is the trees.

　　以尼泊尔西南部的森林为例，被测目标就是树木。

　　During a forest survey, an aircraft-borne lidar sweeps a beam that fires about 70,000 pulses a second over the canopy⁹.

　　在森林探测过程中，载有激光雷达的飞机将每秒产生7万个脉冲的激光束向森林树冠进行扫掠，

　　A sensor¹⁰ on the aircraft records the time it takes to receive the backscattering of pulses, and that is used to compute¹¹ distances to the forest canopy and to the soil beneath.

　　同时安装在飞机上的探测设备会记录收到脉冲反向散射波的时间，然后分别用于计算到树林冠部及到土壤的距离。

　　The result, when processed through the computers of Arbonaut, a Finnish natural-resource-management company, is a three-dimensional image of the forest that can be correlated with, and calibrated¹² by, the efforts of the chaps with the tape measures.

　　经过芬兰自然资源管理公司的Arbonaut计算机进行数据处理后，便可生成与采用卷尺那帮家伙的测量结果相关并可校验的树林三维图象。

　　And that, in turn, can be used to estimate the amount of carbon stored in the plot examined, and extrapolated to calculate the carbon stored in larger areas of forest that have been scanned by lidar, but not measured with tapes.

　　接下来，它还能用于估算所测森林区域的二氧化碳储存量，以此类推，激光雷达所探测的更大片森林区域的二氧化碳储存量也可以计算出来，但用的可不是卷尺。

　　The point of the project, which should be completed by 2014, is to allow Nepal to participate in international carbon-trading schemes that pay poor countries with lots of trees not to cut them down.

　　该项目预计到2014年完成，其实际意义在于能够让尼泊尔参加国际碳交易计划。该计划向拥有大量树木的贫穷国家支付资金，以确保其树木不被砍伐。

　　The Reducing Emissions¹³ from Deforestation and Forest Degradation¹⁴ (REDD) scheme agreed at the United Nations' climate-change conference in Cancún last December may eventually be worth $30 billion a year.

　　联合国气候变化会议去年12月在墨西哥坎昆就减少砍伐森林和森林退化产生的排放计划（REDD）达成协议，确定每年最终可用于森林保护的资金达300亿美元。

　　Nepal wants a slice of that.

　　尼泊尔也想参与其中分得一杯羹。

　　Lidar monitoring may provide a way of making sure it is delivering on its side of the bargain.

　　激光雷达监测可能提供了一种方法，表明尼泊尔履行森林保护协议的决心。

　　Until a few years ago, assessing the amount of plant matter in a forest in a cheap and accurate manner seemed an insurmountable problem, according to Eric Dinerstein, chief scientist of the World Wide Fund for Nature, a conservation group that is also involved in the Nepalese lidar project.

　　环保组织世界自然基金会也参与了尼泊尔激光雷达项目的研究。其首席科学家埃里克（Eric Dinerstein）说，几年前，采用经济和准确的方法对植被数量进行评估似乎还是一项无法解决的难题。

　　Although a woodland's area can be worked out from satellite photographs, that gives only a hazy¹⁵ idea of the mass of the plants growing there.

　　尽管林地的面积能从卫星图片上得到，但它只能给提供我们生长在那里的大片植物的粗略情况。

　　If Forest Resource Assessment Nepal and projects like it are successful, that will change.

　　如果象尼泊尔森林资源评估这样的研究项目能够取得成功，情况就会大有不同。

　　It will then be possible, with reasonable confidence, to pay REDD money out only to those countries that deliver the goods—or, rather, the trees—in sufficient, measurable quantities.

　　我们将有充分理由相信REDD计划拨出的资金可能只会流向那些能够提供货真价实，或更确切的说，树木充足且数量可测量的国家。

1 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。

2 trek   

vi.作长途艰辛的旅行；n.长途艰苦的旅行

参考例句：

• We often go pony-trek in the summer.夏季我们经常骑马旅行。
• It took us the whole day to trek across the rocky terrain.我们花了一整天的时间艰难地穿过那片遍布岩石的地带。

3 assessment   

n.评价；评估；对财产的估价，被估定的金额

参考例句：

• This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
• What is your assessment of the situation?你对时局的看法如何？

4 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。

5 forestry   

n.森林学；林业

参考例句：

• At present, the Chinese forestry is being at a significant transforming period. 当前, 我国的林业正处于一个重大的转折时期。
• Anhua is one of the key forestry counties in Hunan province. 安化县是湖南省重点林区县之一。

6 specimens   

n.样品( specimen的名词复数 )；范例；（化验的）抽样；某种类型的人

参考例句：

• Astronauts have brought back specimens of rock from the moon. 宇航员从月球带回了岩石标本。
• The traveler brought back some specimens of the rocks from the mountains. 那位旅行者从山上带回了一些岩石标本。 来自《简明英汉词典》

7 calibrate   

校准；使合标准；测量（枪的）口径

参考例句：

• Pesticide levels in food are simply too difficult to calibrate.食品中杀虫剂的含量很难精确测定。

8 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。

9 canopy   

n.天篷，遮篷

参考例句：

• The trees formed a leafy canopy above their heads.树木在他们头顶上空形成了一个枝叶茂盛的遮篷。
• They lay down under a canopy of stars.他们躺在繁星点点的天幕下。

10 sensor   

n.传感器，探测设备，感觉器（官）

参考例句：

• The temperature sensor is enclosed in a protective well.温度传感器密封在保护套管中。
• He plugged the sensor into a outlet.他把传感器插进电源插座。

11 compute   

v./n.计算，估计

参考例句：

• I compute my losses at 500 dollars.我估计我的损失有五百元。
• The losses caused by the floods were beyond compute.洪水造成的损失难以估量。

12 calibrated   

v.校准( calibrate的过去式和过去分词 )；使标准化；使合标准；测量（枪的）口径

参考例句：

• Power pesticide dusters can be calibrated and used to apply pertilizer. 动力杀虫剂可以调整用来施肥。 来自辞典例句
• The flexible diaphragm is connected to a plat cantilever-calibrated spring. 柔韧的膜片一扁平的悬臂校正弹簧相连。 来自辞典例句

13 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

14 degradation   

n.降级；低落；退化；陵削；降解；衰变

参考例句：

• There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
• Gambling is always coupled with degradation.赌博总是与堕落相联系。

15 hazy   

adj.有薄雾的，朦胧的；不肯定的，模糊的

参考例句：

• We couldn't see far because it was so hazy.雾气蒙蒙妨碍了我们的视线。
• I have a hazy memory of those early years.对那些早先的岁月我有着朦胧的记忆。