DIVERTING SEAWATER TO SCOUR THE LOWER YELLOW RIVER

1 INTRODUCTION The Lower Yellow River starts from Huayuanko and runs on a plain for about 800 km before emptying into the Bohai Sea. The river is notorious for its extremely heavy sediment load, 1.6 billion tons annually with a relatively small runoff of only 41 km3 at the river mouth. Such a huge volume of sediment is partly deposited in the channel and partly discharged through the estuary into the Bohai Sea. As the tide nearby is weak, a bulk of the sediment cannot be brought to th…     

FLUVIAL PROCESS OF THE DREDGING TEST REACH IN THE LOWER YELLOW RIVER

1THETESTREACHANDDREDGINGIN1997~1998TheYellowRiverhasextended38kmfartherintotheseaeversincethechangeoftherivercourseattheestuarytotheQingshuigouflowpathin1976.InMay1996therivercoursewaschangedtoabranchatthepointof950mabovetheCSQSandtheriverlengthwas16kmshorterthanbefore.Conditionsofincomingwaterandsedimentduringthefloodseasonof1996werefavorablesuchthat3].6milliontonsofsedimentwerescouredbelowLain.Amongthem,11.6milliontonswerescouredbetweenakinandXihekou(47.5km)and2040milliontonswe…     

RANGE SURVEY OF DEPOSITION IN THE LOWER YELLOW RIVER

1 GENERAL DESCRIPTION The Yellow River, running out of the gorges below the Sanmenxia (SMX) and Xiaolangdi (XLD) reservoirs, flows through the vast North China alluvial plain, and finally empties into the Bohai Sea (Fig. 1). The upper part of the Lower Yellow River (LYR), nearly 400 km in length, is confined by levees along both banks. The river wanders with a shallow main channel and broad flood plains. The lower part has a relatively narrow and deep main channel and less b…     

A STUDY ON THE WARPING NEAR IRRIGATION HEADWORK OF THE LOWER REACH OF YELLOW RIVER

IINTRODUCTIONTheYellowRiverisfamousforitsttemendousamountofsedimenttransport.Basedonastatisticaldataanalysis,along-timeaverageannualof1.6billiontonsofsedimententerstheLowerYellowRiver,inwhich400milliontonsaredepositedintherivercharmel.Thesedimentdepositioncausesavapidriseofthebedelevation.Withahistoricalevollltionoftheriverchanges,aso-called"suspendedriver"graduallyformed.UPtonow,thegroundleveloftheareaolltsidetheriverleveesismuchlowerthanthewaterlevelintheriver.Thissituationbringsanex…     

LOCAL SCOUR DEPTH AROUND SPURS IN THE LOWER YELLOW RIVER

1 INTRODUCTION The Lower Yellow River is a suspended river channel bed much higher than the adjacent ground behind the dikes, well known all over the world. The floods flow east into the sea under the constraints of dikes. The safety of the dikes or embankments mainly relies on the protection provided by the river training works that have been constructed and maintained for several thousand years. There are three types of river training works and they are spurs, guide banks, and reve…     

A MATHEMATICAL MODEL FOR UNSTEADY SEDIMENT TRANSPORT IN THE LOWER YELLOW RIVER

1 INTRODUCTIONMany mathematical models for sediment transport have been developed for solving practical Problemsin hydraulic engineering. HoweveT, most of them are not able to simulate the hyper-concentratd flows inthe Lower Yellow Xiver because of the extremely high load concentration of the flows. This paper isdevoted tO the simulation of unsteady sediment trallsport in the Lower Yellow mveLIn this paPer, the riverbed deformation equation is modified and the new expressions for sedi…     

GEOMORPHIC THRESHOLDS FOR CHANNEL EVOLUTION IN THE LOWER YELLOW RIVER

Channel evolution refers to boundary changes of rivers affected by fluvial actions. This paper provides an analysis of the development and formation of stream patterns in the lower Yellow River and presents intensive studies of several critical problems relating to channel evolution, including thresholds of channel gradient and longitudinal profile adjustment, channel surface morphology, response of channel pattern to boundary conditions, critical discrimination of cross sections and the discrimination of channel pattern changes using hydrologic parameters.     

A 2D MATHEMATICAL MODEL FOR THE BED DEFORMATION IN THE LOWER YELLOW RIVER

1 BANK EROSION IN THE LOWER YELLOW RIVER In alluvial rivers, riverbeds are always in a state of transition and development. Two kinds of deformations result for the fluvial process according to certain basic characteristics. One is longitudinal deformation that is characterized by the deformation of a riverbed in the direction of streamwise flow such as riverbed scour or deposition. The other is transverse or lateral deformation that is distinguished by the deformation of a riverb…     

SEDIMENT HAZARDS IN THE LOWER YELLOW RIVER

1DEFINITIONOFSEDIMENTHAZARDHazardsaredefinedasthenaturaleventsthatcauselossesofhumanlifeandproperty.Reasonably,thesedimenthazardsarethehazardsoccasionedbythenatUralphenomenonandprocessesthatarerelatedwithsedimenterosion,transport,andaccumulation.Thelandslideandsoilerosionarethedirectresultsofsedimentmovement.Theoccurrenceofsomeotherhazardsisnotthedirectresultofbutrelatedtosedimentmovement.Forexample,inadditiontometeorolog.icalconditions,somekindsoflandformsarefavorabletoformationoff…     

COMPLICATED FILL-SCOUR BEHAVIORS OF THE YELLOW RIVER AND THE CHANNEL-FORMING PROCESSES

IINTRODUCTIONStreamflowformostriversintheworldcanberegardedasasolid-liquidtwo-phaseflow.Theexistenceofsuspendedsedimenthassomeinfluenceonthestreamflow'sphysicalandmechanicalproperties,whichinturnaffectsthestreamflow'ssedimentcarryingbehaviors(ChienandWan,1983;Chien,1989).Forriverswithrelativelylowsuspendedsedimefltconcentrations,theabove-mentionedeffectisnegligible.However,withtheincreasesinsuspendedsedimentconcentration,thiseffectbecomesincreasinglysignificant;thesediment-carryingbehavi…     

FLOOD AND FLOOD CONTROL OF THE YELLOW RIVER

1 INTRODUCTION Flood of the Yellow River occurred frequently in history. The natures of large impact and heavy losses have made the flood of the Yellow River being in the front rank among major rivers in China. Statistics shows that during the period 602 AC to 1938 BC, embankment of the Lower Yellow River had been breached 1590 times and the channel had changed its course for 26 times among which 6 times were major ones. Thus, flood of the Yellow River has endangered economic cons…     

DIVERTING SEAWATER TO SCOUR THE ESTUARY-A QUEST FOR NEW APPROACH TO REGULATETHE LOWER YELLOW RIVER-

1GENERALTraditionally,theLowerYellowRiverstartsatHuayuankouandrunsonaplainforabout800km,beforeemptyingintotheBohaiSea.Theriverisfedwithextremelyheavysedimentload(1.6billiontonsannuallyuptotheeighties)andrelativelysmallrunoff(46billionm3uptotheeighties)fromitsdrainagebasinupstream.Thisloadofsedimentispartlydepositedinthechannelresultinginaggradationorincreaseinthebedslope.TheremainderisdischargedtotheBobalSea.AsthetidesoftheBohaiSeaareweak,thedepositionintheareaaroundtherivermouthisusual…     

PROGNOSIS OF AGGRADATION IN THE LOWER YELLOW RIVER BY HISTORIC ANALYSIS OF THE MORPHOLOGY OF ITS ABANDONED ANCIENT CHANNEL

1. INTROOUCnONFor a long time, the Lower Yellow River has been aggtading. As a result, the river bed becomesmuch higher than the adjacent land beyond the levees and poses a threat to the safety of the GreatNorthern Plain of China. Since the founding of the New China, great success has been achieved insafeguarding the levee for forty years. The trend of aggravation in lower reaches however is still Soingon and is at a rate even higher than before. That makes the flood control on the LO…     

TWO-DIMENSIONAL SEDIMENT MATHEMATICAL MODEL FOR UNSTEADY FLOW IN THE LOWER YELLOW RIVER

IINTRODUCTIONTheYellowRiverisfamousforitsheaVysedimentloadandcompledpluvialprocessesobviousadvanceshavebeenmadeinthetwo-dimensionalsedimentmathematicalmodel.Amongtile1llodelscreatedbeforethemechanismofsedimenttransportandrelatedphysicalparametel's,suchassedimentvelocity,sedimentcan'yingcapacityandriverfi.ictionetc.arenotyetundel.stoodvery\veil.Thesynchronousobserveddataoftheflowwithsediment,especiallyathyperconcentration,arenotenougllforthemodelcalibration.Thereforethedevelopmentoftwo-di…     

REGULATION OF FLOW AND SEDIMENT LOAD IN THE YELLOW RIVER

Small runoff, large sediment load, and incompatible relationship of flow and sediment load are very important characteristics of the Yellow River. They are also the crux of the most prominent problems of the Yellow River. To solve these problems, the regimes of flow and sediment load have to be improved by increasing water, reducing sediment load, and by using reservoirs to regulate flow and sediment load. The results of experiments for regulating the flow and sediment load in the last three years by the Xiaolangdi Reservoir have indicated that this measure is a realistic and effective way to mitigate the prominent problems in flood control of the Lower Yellow River at present and in the near future. However, the regulation system is still imperfect. It is advisable to speed up the pace of research and construction of the system for regulating flow and sediment load.     

ANALYSIS ON PECULIARITIES OF "92.8"FLOOD EVENT IN THE LOWER YELLOW RIVER

lCOMPOSITIONOFTHE"92.8"FLOODThreerainstormsoccurredfrom7ththrough13,,,August,1992inShaanxiProvince,diStributingfromnorthtosouthinsequence.Therainfallareacoveredtheregionsofintensivesoilerosion,'wheretheaveragerateoferosionis10,000-15',000ton/kmZ'year.Fig.IshowsisohyetsofrainfallintensityinthecatchmentoftheMiddleYellowRiVerdepictingthedistributionoftherainstormsfrom7thto13,,,August,1992(thehydrologicalBureauYRCC,1992).ThecenterofthefirstrainstormwaslocatedattheYikezhaomengPrefec…     

黄河源区日玛曲流域古堰塞湖的沉积特征及环境意义

在黄河源区支流日玛曲河谷发现第四纪湖相沉积,以含砾粉砂、粉砂、粘土互层组合为特征,形成河流的第一阶地基座。通过对该剖面野外岩性观测、^14C测年分析,探讨了古湖形成时代及成因,以及古湖发育时期周围的植被与环境。研究结果发现,古湖形成于3120aBP前后,可能属于地震堰塞湖,于640aBP以后出现决堤事件。     

DEFORMATION OF RIVER BED AND THE CHARACTERISTICS OF SEDIMENT TRANSPORT DURING HYPER-CONCENTRATED FLOOD IN THE YELLOW RIVER

LINTRODUCTIONTheYellowforeriswellknownasaheavilysilt-caacingriverintheworld.Haaer-concentratedfloodsoftenoccurinitsmasterstemandaswellasthetriblltaries.ThecharacteristicsofdeformationandsedimellttranSportdifferfromreachtOreach.Duetohighsedimelltconcelltration,StrongfluvialactionandthenatUreofunSteadysedimenttranSPOrt,problemsandabnormalphenomenonareoflencreated.ThelaterbringinimpacttOnoodcontrolOfthelowerreach.Thus,itishelpfultoenhancetheunderstandingofthemotionlawsOfhaer-concentrat…     

ECONOMIC EVALUATION OF REDUCTION OF DEPOSITION IN THE LOWER YELLOW RIVER BY THE SANMENXIA PROJECT

ＥＣＯＮＯＭＩＣＥＶＡＬＵＡＴＩＯＮＯＦＲＥＤＵＣＴＩＯＮＯＦＤＥＰＯＳＩＴＩＯＮＩＮＴＨＥＬＯＷＥＲＹＥＬＬＯＷＲＩＶＥＲＢＹＴＨＥＳＡＮＭＥＮＸＩＡＰＲＯＪＥＣＴＬＩＧｕｏｙｉｎｇａｎｄＴＵＱｉｈｕａＡｓｓｉｓｔａｎｔＣｈｉｅｆＥｎｇｉｎｅｅｒ，...