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简介:河被知道带沉积负担。在包括Kosi,Brahmaputra,印度和黄的Bagmati河和中国的YarlungTsangpo河的亚洲的许多河为他们过多的沉积负担的马车是众所周知的。在印度,许多水抽象单位沿着河岸被定位。他们的成功取决于沉积负担怎么作为向抽的井的沉重的水流动定位了的沉积被套住很少百米离开河岸。在这个工作,基于在一条运河的推迟的负担变化上的一年的一个数据的分析,在Haridwar定位了,印度,陷井效率变化在来源水的经过期间被学习到抽象很好。就表面下的盆而言,在来源水和抽象以内定位了很好,作为假想安定盆,陷井效率的变化与流入的集中被联系。陷井效率取决于流入的集中,这被观察。为有流入的集中的陷井效率的变化的适当功能的形式也被识别。
简介:UsingfieldobservationsatfourgaugingstationsalongtheInnerMongoliaReachoftheYellowRiverinChina,thispaperexploreseffectsoftheiceonthehydraulicsofthisriverreachforfourdifferentconditions,namely:underopenchannelflow,duringice-runningperiod,theice-coveredperiod,andtheriverbreak-upperiod.Theratingcurveswerefoundtobewellrecognizedunderopenchannelsituations,butweresometimespoorlydefinedandextremelyvariableundericeconditions.Theresultsalsoshowthatthewaterlevelisinsensitivetoflowingicepriortofreeze-up.However,significant,buthardlysurprising,variationswereobservedduringice-coveredconditions.Theratingcurvesforboththeicecoveredconditionandrivericebreakupperiodaredevelopedandsomerelatedhydraulicissuesareexamined.Additionally,theimpactsoftheiceaccumulationandassociatedriverbeddeformationduringiceperiodontheratingcurvesarediscussed.
简介:Reliablefielddataforallhydrologicparametersareoftenunavailableforwatershedsevenforthoseintensivelymonitored.Intheabsenceofreliablesuchdata,verifiedmathematicalrelationsforanareacanbeusedforotherareaswithsamehydrologicandclimaticregimes.Theobjectivesofthisresearchwere:1)toassessthetotalrunoffandsedimentloss,and2)todeveloprainfall,runoffandsoillossrelationsforfourprominentlanduses(includingdegraded,pasture,forestandagriculturelands)intheHilkotwatershed(Pakistan).Fourexperimentalnaturalrunoffplotswereestablishedonthelanduses(degraded,pasture,forestandagricultureland).ThefieldstudyanddatacollectionwereconductedintheHilkotwatershedfrom1999to2005.Regressionanalysiswasconductedtoestablishrelationsamongrainfall,runoffandsoillossforalllandusesusing.Regressionanalysisindicatedgoodcorrelationwithfielddata.
简介:烃探索兴趣为开发新潜水艇暗岩成像技术更新了需要。今天遇到的最重要的问题之一是在暗岩下面的地震成像。在最近的年里,这个问题看起来被长使用部分克服了抵消地震数据。然而近的偏移量数据充分还有待于由于表面以及暗岩的内部异质引起的复杂波形被利用。近正常的发生数据,影响亚暗岩成像,是高度有用的在暗岩层以内理解内部结构。为如此的目标的变换波浪的使用在相当同类的暗岩层作为一种选择被建议了。与合成建模这里行使的一些,我们在处理更多的现实主义、异构的暗岩流动加亮实际困难。完整的波形震动图被计算在地震数据上理解intra-trappean沉积的效果。从印度的Deccan陷井的案例研究在这篇论文被介绍。首先,我们在全面地震图象上讨论设置的沉积的效果。后来,来自这个领域的声音的木头数据被用来用反射率方法并且与领域数据相比计算完整的波浪地反应。使用模式的可行性变换了波浪(在顶和底部暗岩接口的到S并且反过来的P)因为在Kutch区域的亚暗岩成像通过一系列速度深度侧面被讨论。由与领域数据作比较,我们证明在暗岩罐头以内的多重薄layering的效果强烈败坏我们寻求解释并且利用的图象。
简介:FieldexperimentswereconductedontotalloadtransportintheChelichayRiverBasin,amountainouscatchment(1,400km~2)locatedinnortheasternofIran,toevaluatetotalloadformulasincludingfourgravelbedriversandasandbedriver(QaresooRiver).GravelbedriversinChelichayRiverBasincanbegroupedintotwotypes;steepsloperiverswithhighshearvalues(ChehelchayRiverandKhormalooRiver)andmildsloperiverswithlowshearvalues(NarmabRiverandSoosaraRiver).Twodepthintegratingsuspendedloadsamplers(DH-48andD-49),andtwobedloadsamplers(Helley-SmithandBLSH)wereusedtomeasuretotalload.Theperformanceistestedof8totalloadtransportformulaeincluding4macroscopicand4microscopicmethods.Asystematicandthoroughanalysisof59setsofdatacollectedfromsandbedriverindicatethatYangandEngelundandHansenreachtothebetterresults,andfromfourgravelbedriversconfirmedthatthemethodsofKarimandKennedyandEngelundandHansenyieldsthebestresultsforsteepsloperivers,andthemethodsofEinsteinandBijkerarerankedhighestingradualsloperivers.
简介:这研究的目的是估计在印度的东南的海岸在Tirumalairajan河河口在10表面沉积选择重金属(Fe,Mn,Cu,Zn,Pb,Cr,公司和Ni)划分的化学药品。一种五步的顺序的抽取技术被用来估计重金属的环境地位。大多数金属被认为由于在重金属的剩余部分的高可获得性不动。Tirumalairajan河河口的沉积没被重金属弄脏,并且他们没提出任何高生态的风险。重金属的季节的变化比在季风季节在夏天是稍微更高的。因素分析也被执行与沙,淤泥,泥土,有机物,pH,咸度和另外的金属在不同部分理解金属的协会。在Q模式和R模式簇分析之间的关系为在两个季节识别污染层次是有用的。重金属的丰富与地球表面形成学、人为的来源一起是相关的,这被证明。在沉积的全部的金属集中的信息不为在环境估计金属行为是足够的,但是顺序的抽取技术在估计污染沉积的环境影响是更有效的。
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简介:Retrogressiveerosion,awidespreadphenomenonofsedimenttransportinreservoirs,oftenimpactsonboththereservoircapacityandthesedimentationinthedownstreamriverchannel.BasedonfielddatafromtheSanmenxiaReservoirandtheLowerYellowRiveroverthepastdecades,threecoursesofretrogressiveerosionwithdistinctivefeatureswereanalyzed.Theresultsindicatethatretrogressiveerosion,especiallycausedbyrapidreductioninthewaterleveltillthereservoirisempty,oftenresultsintheserioussiltationofthelowerYellowRiverandthreatensthesafetyofthefloodcontrolintheLowerYellowRiver.Unreasonableoperationofthereservoirandincominghyperconcentratedfloodsaccompaniedbyretrogressiveerosionalsoaggravatethesiltationofthemainchanneloftheriver.However,areasonableoperationmodeofthereservoirsonamed”storingtheclear(lowsedimentconcentration)waterinthenon-floodseason,andsluicingthemuddy(highsedimentconcentration)waterinthefloodseason”wasfound,whichmightmitigatethedepositioninboththereservoirandtheLowerYellowRiver.Thisoperationmodeprovidesimportantexperienceforthedesignandoperationoflargereservoirsinotherlargeriverscarryinghugeamountsofsediment.
简介:MostofthestudiesonArtificialNeuralNetwork(ANN)modelsremainrestrictedtosmallerriversandcatchments.Inthispaper,anattempthasbeenmadetocorrelatevariabilityofsedimentloadswithrainfallandrunoffthroughtheapplicationoftheBackPropagationNeuralNetwork(BPNN)algorithmforalargetropicalriver.ThealgorithmandsimulationaredonethroughMATLABenvironment.Themethodologycomprisedofacollectionofdataonrainfall,waterdischarge,andsedimentdischargefortheNarmadaRiveratvariouslocations(alongwithtimevariables)andapplicationtodevelopathreelayerBPNNmodelforthepredictionofsedimentdischarges.Fortrainingandvalidationpurposesasetof549datapointsforthemonsoon(16June-15November)periodofthreeconsecutiveyears(1996–1998)wasused.Fortestingpurposes,theBPNNmodelwasfurthertrainedusingasetof732datapointsofmonsoonseasonoffouryears(2006–07to2009–10)atninestations.Themodelwastestedbypredictingdailysedimentloadforthemonsoonseasonoftheyear2010–11.ToevaluatetheperformanceoftheBPNNmodel,errorswerecalculatedbycomparingtheactualandpredictedloads.Thevalidationandtestingresultsobtainedatalltheselocationsaretabulatedanddiscussed.Resultsobtainedfromthemodelapplicationarerobustandencouragingnotonlyforthesub-basinsbutalsofortheentirebasin.Theseresultssuggestthattheproposedmodeliscapableofpredictingthedailysedimentloadevenatdownstreamlocations,whichshownonlinearityinthetransportationprocess.Overall,theproposedmodelwithfurthertrainingmightbeusefulinthepredictionofsedimentdischargesforlargeriverbasins.
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简介:ObservationoftheoperationoftheSanmenxiaReservoirontheYellowRiverhasledtotheconclusionthattopreserveacertaineffectivestoragevolumeforreservoirsbuiltonheavilysilt-ladenriversisfeasibleifthereservoirisoperatedaccordingtotheprincipleknownas"storingtheclearwateranddischargingthemuddyflow".Therelativestabilityofthebedelevationattheendofthebackwaterandthereservoir'serosionanddepositionequilibriumdependonthecompatibilityofthepoollevelmaintainedinnon-floodseasonswiththeconditionsofflowandsedimentloadduringfloodseasons.OperatingthereservoirtoregulatethefloodandsedimentloadduringfloodseasonscanreducetherateofaggradationintheLowerYellowRiver.Thebasicconditionforapplyingtheoperationmodeof"storingtheclearwateranddischargingthemuddyflow"isthatasufficientamountofwatershouldbeusedfordischargingsedimentduringfloodseasons.Undertheconditionofextremelylowflowyears,reservoirsedimentationcannotbeavoidedevenifthisoperationmodeisadopted.
简介:Thepaperpresentsthe3DfiniteelementsimulationoftidalflowandSedimenttransportintheestuarineregionoftheHaiheriver.Theproposedmodeladoptssigma-transformationofthehydrodynamicandsedimenttransportequations.Thehydrodynamicandsedimenttransportmodelsareverifiedincaseofasimpletestproblemforwhichanalyticalsolutionsareavailable.FinallythemodelsareappliedtomuddyHaiheriverestuaryofNorthChinaanditisclaimedthathydrodynamicandsedimenttransportmodelsgiveareliablecomparisonwiththeobservedfielddata.However,therearecertaindiscrepancies,andsomereasonablequestionsregardingthepresentstate-of-art,inthemodelingofthree-dimensionalmultilevelhydrodynamicsandsedimenttransport,whichareprovidedbelowforanswer.
简介:TheYellowRiveristhecradleofChina.Ithadlongbeenthecenterofpolitics,economicsandcultureofChinainhistory.LargecoverageflooddisasteroccurredfrequentlyintheYellowRiverbasinandthelosseswereoftenheavy.Thus,theYellowRiverisalsoconsideredastheserioushiddendangerofChina.SincethefoundingofnewChina,structuralandnon-structuralsystemsoffloodcontrolhavebeenestablishedbasically.Tremendoussuccesseshavebeenmadeonfloodcontrol.Intothe21century,floodcontrolstandardoftheLowerYellowRiverhasbeenincreasedsignificantlywiththeoperationoftheXiaolangdiReservoir.However,problemsoftheYellowRiverarecomplicatedandthetasksforsolvingtheseproblemsarearduous.Particularly,thesedimentationproblemcan'tbesolvedcompletelyinthenearfuture.Thesituationof"suspendedriver"andthreatoffloodwilllongexist.Therefore,supportedbyrapidsocialandeconomicaldevelopmentofthenationandreliedonadvancedtechnology,thefloodcontrolsystemshallbeperfected.Meantime,studyoftheYellowRivershallbeenhancedinordertobetterunderstandtheflood,getwithitanduseitthustoreduceflooddisaster.
简介:1INTRODUCTIONHumanactivitiesmayinducesignificantchangesinsedimenttransportcapacityofaluvialriverchannelsandcausechangesinthe...