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
Environmental Science Why does the professor mention that drought is often blamed as the cause of the Dust Bowl?
Environmental Science Why does the professor mention that drought is often blamed as the cause of the Dust Bowl?
admin
2014-09-29
27
问题
Environmental Science
Why does the professor mention that drought is often blamed as the cause of the Dust Bowl?
Environmental Science
Narrator
Listen to part of a lecture in an environmental science class.
Professor
OK, now let’s talk about another environmental concern—soil erosion. It’s a major problem, all around the world. Sometimes erosion damages soil so severely that the land can no longer be cultivated and it’s just abandoned. That happened in a big way right here in the United States. Some of you have probably read the novel The Grapes of Wrath. And maybe you remember that the story took place in the 1930s, during the time of what was called the Dust Bowl.
Dust Bowl is a term we use to describe an ecological and human disaster that took place in the southern Great Plains region. For nearly eight years, dust and sand blew across the area and covered everything. It was so bad it even made breathing and eating difficult. . . and farmers could only look on helplessly as their crops were destroyed and the land .. . and their lives ... ruined.
Now, there’d always been droughts and strong winds in that region. But that was OK because the native grasses had deep roots in the ground that were able to hold the soil in place. So the wind wasn’t able to, you know, erode the soil too badly. This changed, though, between 1900 and 1930. Agriculture was expanding rapidly then, and lots of farmers in the southern Great Plains wanted to grow wheat and other crops they could sell for cash—uh, crops that would be profitable. So they ripped up much of the grassland to plant these crops like wheat, which don’t hold the soil down nearly as well. At the same time, livestock—uh, cattle, too many of them—were feeding on grasses in the area and damaging a lot of the grassland. So these animals caused even more erosion of the soil.
It didn’t help that many of the actual owners of the land were not living anywhere near the area—a lot of the landowners lived way back east, and rented out the land to local people who lived on the land and worked on it, but, um, didn’t have much reason to take really good care of it. I mean, it wasn’t their land, right? The tenant farmers weren’t really interested in conserving someone else’s soil—not for the long term, anyway.
Also, some thought the land couldn’t really be damaged—you know, that the soil was so rich and deep that... it didn’t matter if the topsoil, the soil on the surface, blew away. They thought they could just plow up more. But they were wrong. Good top-soil takes a long time to form—it can literally take thousands of years to create good topsoil that will grow vegetation—and a very short time to ruin it. So after only a few years of excessive plowing, the land pretty much couldn’t be farmed anymore. And people moved on to other places and let the old areas just sit there. And when they didn’t plant anything on that land, that made it vulnerable to even more erosion. So it was kind of a vicious cycle, you could say.
Another problem, ironically, was that advances in technology were actually destroying the land, instead of improving it. A lot of farmers were using huge new tractors that dug deep into the ground and tore up a lot of the soil.
And then, of course, there was the weather. You know, when people look back on the Dust Bowl era, they tend to blame the drought—the lack of rain between 1934 and 1937. We can’t ignore the drought—I mean, it was the worst on record at the time and did help bring on this disaster. But—without the soil destruction—the drought alone wouldn’t have resulted in the devastation we call the Dust Bowl. It was poor farming techniques that made that happen.
Since then, though, we’ve paid more attention to trying to prevent a future Dust Bowl. One thing Congress did was enact a massive government effort to improve soil conservation, called the Soil Erosion Act. Under this law, large stretches of land in the southern Great Plains were identified as being at risk for erosion and were taken out of production and turned into permanent grassland. What that did—by protecting the land from excessive farming—was to stabilize the soil. Also, the Soil Erosion Act helped educate farmers to practice better soil conservation techniques, like reducing how often they plowed and using better equipment that would, you know, minimize damage to the soil structure.
选项
A、To explain that many tenant farmers had to leave their land before the Dust Bowl era
B、To emphasize that the Dust Bowl resulted mainly from soil erosion
C、To show why the local population increased when rainfall returned to normal
D、To prove that the drought was the worst on record at that time
答案
B
解析
转载请注明原文地址:https://jikaoti.com/ti/FxhYFFFM
0
托福(TOEFL)
相关试题推荐
Whatinformationwasgivenbyeachwriter?ChooseyouranswersfromtheboxandwritethelettersA-FnexttoQuestions24-27.A
ChooseTWOletters,A-EWhichTWOproblemsdoSamandthetutoridentifyconcerninggroupassignments?APersonalrelationships.
Completethenotesbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswerENVIRONMENTALCHANGEDISCUSSIONInSouthe
Completethetablebelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswer.Talkingaboutthehistoryofbikes
Listentothedirectionsandmatchtheplacesinquestions11-15totheappropriateplaceamongA-Eonthemap.HealthCentre
Whatfeaturedothespeakersidentifyforeachofthefollowingcourses?ChooseFIVEanswersfromtheboxandwritethecorrect
Completethenotesbelow.WriteONEWORDAND/ORANUMBERforeachanswer.DRIVINGSCHOOLExampleAnswerLookingfordrivingless
Completethenotesbelow.WriteONEWORDAND/ORANUMBERforeachanswer.DRIVINGSCHOOLExampleAnswerLookingfordrivingless
ChooseTWOletters,A-E.WhichTWObenefitsofthisactivitytothestudentsarementionedbytheprofessor?ATheybecomemore
Completethenotesbelow.WriteONEWORDONLYforeachanswer.Episodicmemory-theabilitytorecalldetails,e.g.thetimeand
随机试题
阅读下文,回答问题。独语何其芳
地图舌任何年龄均可发生.但多见于
以下措施不可以有效控制粉尘爆炸的是()。
装载出境动植物、动植物产品和其他检疫物的运输工具,经口岸检验检疫机构查验合格后方可装运。( )
依据()的不同,商品库存可分为周期库存、在途库存、安全或缓冲库存、战略库存、呆滞库存等。
某次考试满分为150分。甲乙分数之和为278,乙丙分数之和为281,丙丁分数之和为282,如果甲比丁的分数高2分,则乙的分数为()。
“建设有中国特色的社会主义”新命题是在党的()正式提出的。
Illiteracymaybeconsideredmoreasanabstractconceptthanacondition.WhenafamousEnglishwriterusedthe(1)_____overt
YouwillhearaninterviewaboutGalapagosAdventureTourinEcuador.Asyoulisten,youmustanswerQuestions21to30bywriti
Crimeplaguesoursociety,almostallaroundusinourdailylives.Dailywehearmanyinstancesof【C1】______crimessuchasmurd
最新回复
(
0
)