简介:TheconstructionoftheTisAbayIIhydropowerprojectinEthiopia,whichisconsideredtobeakeyelementinEthiopia'spowerdevelopmentprogramme,isnearingcompletion.ItishopedthattheUS$63Mproject,whichisfundedbytheEthiopiangovernment,willhelpthecountrymeetits10-12%annualgrowthinelectricitydemandandsupporttheexpandingeconomy.
简介:Rivericeisanimportanthydraulicelementintemperateandpolarenvironmentsandwouldaffecthydrodynamicconditionsofriversthroughchangesbothintheboundaryconditionsandthethermalregime.Theriverbendhasbeenreportedasthecommonlocationfortheinitiationoficejamsbecausethewaterflowalongariverbendismarkedlyaffectedbythechannelcurvature.Inthisarticle,theexperimentalstudiesabouttheiceaccumulationinariverbendarereviewed.Basedonexperimentsconductedsofar,thecriteriafortheformationoficejamsintheriverbend,themechanismsoftheiceaccumulationintheriverbendandthethicknessprofileoftheiceaccumulationintheriverbendarediscussed.Thetwo-equationturbulencemodelisusedtosimulatetheiceaccumulationunderanicecoveralongariverbend.Aformulaisproposedfordescribingthedeformationoftheicejambottom.Ourresultsindicatethatallsimulatedthicknessoftheiceaccumulationagreesreasonablywellwiththemeasuredthicknessoftheiceaccumulationinthelaboratory.