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
外语
Removing Dams P1: In the last century, many of the dams in the United States were built for water diversion, agriculture, factor
Removing Dams P1: In the last century, many of the dams in the United States were built for water diversion, agriculture, factor
admin
2018-10-18
60
问题
Removing Dams
P1: In the last century, many of the dams in the United States were built for water diversion, agriculture, factory watermills, and other purposes that allowed farming on lands that would otherwise be too dry, with low-cost hydroelectric power generation being a very significant side benefit. Building these dams was rather labor-intensive, which created jobs for workers and stimulated regional economic development. But those opposed to large dams can marshal a sobering array of criticisms based on those already built, which have provided some benefits but have without exception destroyed river environments and the human communities that depend on them.
P2: Many, perhaps most, of the more than 90,000 dams in the country are now obsolete, expensive, and unsafe, and were built with no consideration of the environmental costs. As operating licenses come up for renewal in 1999, habitat restoration to original stream flows will be among the options considered. As these dams age and decay, they can also become public safety hazards, presenting a failure risk and a dangerous nuisance. Worse still, with the growth of the American population, more people are moving into risky areas. Dams that once could have failed without major repercussions are now upstream of cities and development. In 1998, the Army Corps announced that it would no longer be building large dams. In the few remaining sites where dams might be built, public opposition is so great that getting approval for projects is unlikely.
P3: For many years, the United States Fish and Wildlife Service had advocated the removal of the Edwards Dam, which was built in 1837 on the Kennebec River in Augusta, Maine, to ease navigation and generate electricity. The Kennebec River was once home to all ten species of migratory fish native to Maine, along with several thriving commercial fisheries. Damming the river not only transformed the natural landscape, but it also prevented migration of salmon, shad, sturgeon, and other fish species up the river.
In 1999, the Federal Energy Regulatory Commission (FERC) refused the renewal of the dam license due to excessive negative environmental impact, and the dam was removed, freeing a 17-mile stretch of the Kennebec River that had been submerged for 162 years. P4: The cost of keeping outdated hydroelectric equipment running decades after it was installed or upgrading dam safety systems may not be worth it. This was proven true on the Elwha River in the Olympic National Park in Washington when an extraordinarily rich salmon habitat was being disrupted by an outdated hydroelectric plant. Before dams were built on the Elwha River, 400,000 salmon returned each year to spawn, but that number dropped to fewer than 3,000 after dams were put up. Once the hydroelectric power generating capacities of the dams had outlived their useful lives, the importance of this salmon habitat necessitated the removal of the dams on the Elwha River. Simply removing the dams will not restore the salmon, however. Where 50-kilogram king salmon once fought their way up waterfalls to lay their eggs in gravel beds, there are now only concrete walls holding back still water and deep beds of muddy deposits.
P5: When the negative environmental effects outweigh the benefits, a dam may be considered for removal. The Hetch Hetchy Dam, whose construction was one of the first major defeats of the nascent American environmental movement, was approved in 1913 to assist earthquake-ravaged San Francisco. Environmentalists and nature lovers, who said the valley’s beauty surpassed even Yosemite Valley’s, have constantly fought for its removal. They claim that restoring Hetch Hetchy Valley could reclaim an area that is half the size of Yosemite Valley and nearly identical in terms of beauty. Revenue and increased local spending from tourism could offset some or all of the losses from removing the dam. This problem can be thought of as appraising the relative value of two scarce resources, water and space, in Yosemite National Park.
P6: How does one weigh the many different economic, cultural, and aesthetic considerations for removing or not removing these dams? Do certain interests, such as the rights of native people or the continued existence of native species of fish or wildlife, take precedence over economic factors, or should this be a utilitarian calculation of the greatest good for the greatest number? And does that number include only humans, or do other species count as well?
P4: ■ The cost of keeping outdated hydroelectric equipment running decades after it was installed or upgrading dam safety systems may not be worth it. ■ This was proven true on the Elwha River in the Olympic National Park in Washington when an extraordinarily rich salmon habitat was being disrupted by an outdated hydroelectric plant. ■ Before dams were built on the Elwha River, 400,000 salmon returned each year to spawn, but that number dropped to fewer than 3,000 after dams were put up. ■ Once the hydroelectric power generating capacities of the dams had outlived their useful lives, the importance of this salmon habitat necessitated the removal of the dams on the Elwha River. Simply removing the dams will not restore the salmon, however. Where 50-kilogram king salmon once fought their way up waterfalls to lay their eggs in gravel beds, there are now only concrete walls holding back still water and deep beds of muddy deposits.
According to paragraph 5, why do environmental groups want the Hetch Hetchy Dam removed?
选项
A、To assist earthquake-ravaged San Francisco.
B、To compete with Yosemite Valley
C、To increase the size of Yosemite National Park
D、To restore a valley to its original beauty
答案
D
解析
【推断题】第3句说环境保护主义机构认为赫奇峡谷恢复后可以增加大约有优胜美地峡谷一半的规模,而且可以恢复得与它一样美丽。所以环境保护机构想拆掉赫奇大坝是为了恢复该峡谷原本的美景。
转载请注明原文地址:https://kaotiyun.com/show/uwfO777K
0
托福(TOEFL)
相关试题推荐
Completethenotesbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswer.HOUSERENTALExampleAnswerName:Ma
Completethenotesbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswer.HOUSERENTALExampleAnswerName:Ma
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.HistoryofweatherforecastingE
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.HistoryofweatherforecastingE
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.AdvertisingEffectTheimportantfactortoconsiderThe【
Completethenotesbelow.WriteONEWORDONLYforeachanswer.EffectsofurbanenvironmentsonanimalsIntroductionRecenturba
Completethenotesbelow.WriteONEWORDONLYforeachanswer.EffectsofurbanenvironmentsonanimalsIntroductionRecenturba
Whatdidthewomanfinddifficultaboutthedifferentresearchtechniquessheused?ChooseFIVEanswersfromtheboxandwritet
A、Newton’slifeandtimes.B、TheinfluenceofearlierscientistsonNewton’sideas.C、Howgravityrepelsobjectsveryclosetoe
WATERANDLIFEONMARS1Thepresenceorabsenceofwaterhasadirectbearingonthepossibilityoflifeonotherplanets.In
随机试题
价值分析方法就是通过认知和评价社会现象的价值属性,从而揭示、批判或确证一定社会价值或理想的方法。下列哪些选项正确说明了价值分析方法?()
楼宇自动化的特点是()。
某项目评价区进行生物多样性调查时布设3个草地样方,物种S1、S1、S3的株数见下表,则该评价区群落的多样性指数是()。
混凝土在()是可塑的。
有20位运动员参加长跑,他们的参赛号码分别是1、2、3……20,至少要从中选出多少个参赛号码,才能保证至少有两个号码的差是13的倍数?()
()让应聘者自由地发表意见或看法,以获取信息,避免被动。
俗话说“靠山山倒,靠水水流,靠自己不会倒”,这表明的哲学原理是()。
RobertTrivers’snewbooktheFollyofFoolsisacuriousdocument—abookaboutdeceptionandself-deceptionthatisitselfde
设数组a[1..10,5..15]的元素以行为主序存放,每个元素占用4个存储单元,则数组元素a[i,j](1≤i≤10,5≤j≤15)的地址计算公式为_____。A.a-204+2i+jB.a-204+40i+4jC.a-84+i+jD.a-6
城市一直在破坏它们的周围环境,并常常为之付出代价。科学家发现,一座老城在泥土下掩埋了千百年就是因为砍树过多而被洪水淹没的。此外,城市会给市民带来许多问题。据估计,到2050年时,城镇居民的数量将在人类历史上第一次超过农村人数。随后30年内,城市居民人数将达
最新回复
(
0
)