首页
登录
职称英语
Removing DamsP1: In the last century, many of the dams in the United States wer
Removing DamsP1: In the last century, many of the dams in the United States wer
游客
2024-01-03
7
管理
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. [br] The word "disrupted" in the passage is closest in meaning to
选项
A、modified
B、affected
C、upset
D、discharged
答案
C
解析
【词汇题】disrupted意为“扰乱”。
转载请注明原文地址:https://www.tihaiku.com/zcyy/3328755.html
相关试题推荐
UnitedStatesGovernment[img]2014m9s/ct_etoefm_etoeflistz_0092_20149[/img][br]
UnitedStatesGovernment[img]2014m9s/ct_etoefm_etoeflistz_0092_20149[/img][br]
The21stcenturyhasbegun.Whatchangesdoyouthinkthisnewcenturywill
EconomicDeclineinEuropeDuringtheFourteenthCenturyP1:Someverynegative
EconomicDeclineinEuropeDuringtheFourteenthCenturyP1:Someverynegative
EconomicDeclineinEuropeDuringtheFourteenthCenturyP1:Someverynegative
EconomicDeclineinEuropeDuringtheFourteenthCenturyP1:Someverynegative
EconomicDeclineinEuropeDuringtheFourteenthCenturyP1:Someverynegative
EconomicDeclineinEuropeDuringtheFourteenthCenturyP1:Someverynegative
EconomicDeclineinEuropeDuringtheFourteenthCenturyP1:Someverynegative
随机试题
Theissueofwherethepeacetalkswillbeheldmayseem______,buttothepart
[originaltext]M:Guesswhatcameinthemailtoday?W:What?M:Myacceptancel
Theoldestandsimplestmethod,then,ofdescribingdifferencesinpersonali
[originaltext]Requestingsomeone’sbusinesscardisastraightforwardproce
当符合()条件之一时,汽车库的汽车疏散出口可设置1个。A.Ⅳ类汽车库
社会因素起着决定作用,并与现代生活方式与行为密切相关的疾病或社会病理现象被称为A
成瘾行为的重要特征包括( )。A.一旦恢复成瘾行为,戒断症状将会消失,同时出现
公债负担率是指()。A.公债余额/GDP B.公债发行额/财政支出
社会工作价值观不同于个体的价值观,也不同于一般的社会价值观,它是社会工作者专业共
在实践中,只有以金融期货合约为基础资产的金融期权交易,而没有以金融期权合约为基
最新回复
(
0
)