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《a buffer from the storms：從風(fēng)暴的緩沖》由會員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在教育資源-天天文庫。
1、AGeospatialActivityABufferfromtheStormsInrecentyears,manyhurricaneshavemadelandfallintheUnitedStates,withthe2004and2005hurricaneseasonsbeingparticularlyactive.In2004,fivenamedstormsmadelandfallintheUnitedStates.Thestormscausedover3,132deathsand$50billionindamages.Thenextyear,sevenhurr
2、icanesmadelandfallintheUnitedStatescausingover2,280deathsand$128billionindamage.Mostofthedeathsanddestructionin2005resultedfromfiveofthesestorms:Dennis,Emily,Katrina,Rita,andWilma.HurricaneKatrinaandits30-footstormsurgedevastatedsoutheastLouisianawhileWilmawasthemostpowerfulhurricanee
3、verrecordedintheAtlanticBasin.OverhalfoftheUnitedStates’populationliveswithinfiftymilesofthecoastandmuchofourcoastlineisbeingdevelopedtosupportitsgrowingpopulation.InLouisiana,acomplexnetworkofleveesandcanals,builttoprotectNewOrleansfrombeingfloodedbytheMississippiRiver,preventedsiltf
4、romreplenishingthecoastalmarshes.ThesesamemarsheswouldhavepartiallyprotectedNewOrleansfromHurricaneKatrina.Duringastormevent,coastalmarshes,wetlands,andbarrierislandsserveasthefirstlineofdefenseagainsthurricanes.Thevegetationandsedimentscanslowdownthestormsurgeandabsorbsomeofthestorm’
5、senergyandwater,actingasa“buffer”fromthestorms.Whilesturdyvegetation,suchasshrubsandcypresstreesoffermoreprotectionthangrassesagainsthighwinds,marshgrassescanabsorbincreasedwaterlevels.Removalofcoastalvegetationremovesthenaturalprotectiontheeplantsprovide.Scientistsestimatethatforever
6、ysquaremileofwetlandslostinanarea,stormsurgerisesbyonefoot.ExploringHurricanesalongtheEastCoast·LaunchMyWorldGIS.OpentheprojectfilenameHurricanes.m3vz.TheprojectshouldopendisplayingtheU.S.StatesandCountrieslayers.·TurnontheAtlanticHurricaneTracts1851-2006layer.Toturnalayeron,clicktheS
7、how/HideLayerboxlocatedonthefarrightsideofthelayer’scontrolpanel.Whenthelayerison,aneye,,willappearinthecheckbox.oUsethe,,andtoolstoexploretheAtlanticHurricaneTracts1851-2006layer.Tip:Ifyouzoomintoofar,usetheZoom-to-the-Previousbuttonor,theZoom-to-Allbutton.Hurricanesarelargetropicals
8、torms
