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230 个结果
  • 简介:Thepaperprovidesacomprehensivetestingoftheapplicabilityof13sedimenttransportformulasunderdifferentflowandsedimentconditions.Thedimensionlessparametersusedfortestingthereliabilityandsensitivityofformulasaredimensionlessparticlediameter,relativedepth,Froudenumber,relativeshearvelocity,dimensionlessunitstreampower,andsedimentconcentration.Atotalof3,391setsoflaboratoryandriverdataareusedinthetests.Engineersmayfindthetestresultsusefultotheirselectionofformulasunderdifferentflowandsedimentconditions.

  • 标签: Accuracy DIMENSIONLESS parameter Sediment transport formula
  • 简介:Thispaperprovidesastep-by-stepderivationofthesedimenttransportfunctionsbyEngelundandHansen(1967)andbyAckersandWhite(1973).ThetheoreticalderivationsdemonstratethatthesetwofunctionsarecloselyrelatedtoBagnold's(1966)streampowerandefficiencyconcepts.

  • 标签: SEDIMENT transport STREAM power UNIT STREAM
  • 简介:Flushingpipeoutletsareprovidedatthefloorofsedimentationbasinsforflushingoutofthedepositedsediments.Theseoutletshavetobepositionedinsuchawaysoastoremovethedepositedsedimentseffectively.Intheabsenceofrationalmethodforthelocation,presentlytheoutletsarelocatedbyjudgment.Areviewofliteratureindicatedthatthereisnojudiciousmethodavailableforobtainingtheoutletdiameter.Presentedhereinarethedesignequationsfortheflushingoutlets.Itishopedthattheequationwillbeusefultothedesignengineers.

  • 标签: Canal design FLUSHING pipe Limit deposit
  • 简介:在这份报纸,在年度流量和沉积运输的变化被从10使用长期的观察数据向南向北从远方越过中国在10条大河里计量车站到远方估计了。年度沉积收益通常在过去的一半有一个减少的趋势,这被发现世纪。每区域根据在年度流量和沉积的变化让步,中国的河能被分类进下列三个组:1)有减少的年度沉积运输和稳定的流量的河;2)有减少的年度沉积运输和流量的河并且3)有极大地减少的年度沉积运输和减少的年度流量的河。结果显示那,在所有南部的河里(到包括Huaihe河的Huaihe河的南方),在平均年度流量有小变化但是在年度沉积运输的戏剧的减少。然而,在北河里,年度沉积收益和流量显示出减小的重要证据。为了进一步在年度流量和沉积调查最近的变化,搬运,来自这10个计量车站在的短期的观察数据最近10年被估计了。结果证明年度沉积运输和流量在过去的10年里在北河里显著地减少了。在Lijin车站把黄河用作一个例子,为最后10年的平均年度流量仅仅是长期的平均价值的1/3和最后10年的平均年度沉积收益仅仅是长期的平均价值的1/4。更不平常地,在Yongding河里,年度沉积收益接近了零,流量显著地减少了。另外,在流量和沉积运输的变化上的人的活动的影响被讨论了。

  • 标签: 中国 径流 黄河 长江 泥沙沉淀
  • 简介:许多西方的美国被认为是牧场。牧场区域生产好处和产品的多样的混合,并且在生态系统上下文,他们的全面健康具有国家重要性。因为从一个分水岭的沉积产量是所有土壤的综合表情,侵蚀和沉积处理发生在它以内,我们寻求确定并且作为牧场健康的措施在土壤/地点稳定性和分水岭功能的上下文解释沉积产量,是逻辑的。综合推迟的沉积取样的深度与流量用斜槽测量了在西南的美国从二个试验性的分水岭计算输沙量和收益被相结合。为单个流量事件的沉积收益估计被加从这二个牧场分水岭生产年度沉积产量的估计。估计的年度沉积收益数据然后与沉积交货比率和土壤损失忍耐的概念被相结合在分水岭规模估计土壤/地点稳定性。分析从分布式的分水岭进程用沉积收益估计建议那,时间空间平均土壤损失忍耐值是不一致的。因此,新分布式的土壤/地点稳定性标准被需要在估计牧场分水岭的健康代替土壤损失忍耐概念。沉积搬运/产出模型在一个分水岭在内部点被使用模仿分布式的沉积过程。然而,这些模型的申请要求刻度和确认数据并且因此依赖于沉积集中和收益数据库的可获得性。因此,另外的努力被要求与继续的测量一起通过历史的数据的营救造沉积收益数据库并且在存在和新采样地点监视。

  • 标签: SEDIMENT YIELD Rangalang health ECOSYSTEM CONTEX
  • 简介:ThehydrodynamicandthesedimenttransportpatternswithintheestuaryoftheYangtzeRiverarecomplexbecauseofinteractionoffluvialandthetidalforces,dependingonfreshwaterdischargeandtidalrange.Basedonthedatameasuredinrecentyears,thispaperdiscussesthecharacteristicsofflowandsedimentmovementintheYangtzeRiverEstuaryandtheirinfluencesontheevolutionoftheestuary.

  • 标签: YANGTZE RIVER Estuary Sediment transport TIDAL
  • 简介:TheWorldAssociationofSedimentationandErosionResearch(WASER)establishedtheAwardfordistinguishedcontributionstosedimentresearchin2004.ThisawardistoprovideinternationalrecognitionfordistinguishedcontributionstothesedimentstudiesthroughoriginalandilluminatingresearchpaperspublishedintheInternationalJournalofSedimentResearch.Sevenpaperspublishedin2004-2009havebeenawardedthedistinguishedcontributionsawardin2007and2010.Aselectioncommittee,consistsof7scientistsfrom6counties,wasestablishin2012,whichscreened125paperpublishedinInternationalJournalofSedimentResearchduring2010-2012.Copiesof15papersintheshortlistweresenttomembersofthecommitteeandeachmemberwasrequestedtorecommend3papersfortheaward.ThevotingforthedistinguishedcontributionsawardstartedfromNovember1,2012viaemail.Allmembersoftheselectioncommitteehavereadthepapersandvotedfortheawardbasedonscientificmeritsofthesepapers.UptoJanuary10,2013,allthesevenmembershavesentbacktheirvotes,andtheresultsarethereforevalid.Thefollowing

  • 标签: 泥沙 国际期刊 研究论文 沉积物 启发性
  • 简介:Laboratoryexperimentshavebeencarriedouttostudythecharacteristicsofsedimenttransportinsteepstreams.Thequestionisdiscussedwetheranarmouredsurfacesisdestroyedduetothetransportofmaterial,becauseadditionalimpulsesareactingonit,orthelayerisshelteredbythetransportedmaterial,becauseapartofthestreampowerisusedtomovethematerial.Accordingtotheresultsofthepresentedexperiments,inwhichtheinfluenceofthefeedingrateandthefeedingdurationhavebeeninvestigated,transportedmaterialreachinganarmouredriversectionfromupstreamalwaysremobilzesbedmaterial,whichisimmobileunderclearwaterflowconditions.Todecideifastaticarmourlayeriseitherdestroyedornot,twosimplecriteriawerechosen:oneconsideringthegrain-sizedistributionoftheerodedbedmaterial,andanother,whichreferestotheamountoferodedbedmaterial.

  • 标签: SEDIMENT transport BED stability Armored LAYER
  • 简介:Thepressureandimpactonlargerivershaveincreasedgreatlyinrecentyears,asaconsequenceoftheirexploitationtomeetvarioushumanneeds.Largeriversareparticularlyexposedtoproblemsofmultipleuses,oftenwithconflictingaims.Attheglobalscaleriversystemsareincreasinglyalteredbydams,leadingtointerruptionofcontinuityandadisruptedsedimentregime,whichresultsinfar-reachingproblems.Thesechallengespointalsototheneedformoreintegratedmanagementapproachesandconsiderationofcatchment-riverinteractionsemphasizinglandusemanagementandeffectsoftheseuses.Attheglobalscale,thereiscurrentlynooverviewassessmentofthecurrentstatusoftheworld’slargerivers,theconflictingdemandsonsuchrivers,andlikelyfutureanthropogenicimpacts,aswellasthepotentialforrestoration,improvementsinintegratedmanagementandtheassociatedproblemscausedbytheirmultipleuses.ThespecialissueintheInternationalJournalofSedimentResearchon"Sedimentloadsandprocessesinlargerivers"aimstoprovideaglobalforumforawide-rangingdiscussionofkeyissuesrelatedtoresearchonlargeriversandtotheireffectiveandsustainablemanagement,involvingbothscientistsanddecisionmakers.Thesequenceofpapersinthespecialissuehighlightsthecurrentsituationindifferentriversystemswithregardtomorphodynamicreactionsof

  • 标签: 大河 泥沙量 土地使用管理 河流系统 全球范围 相互作用