简介：Basedonthetensoranalysisofwater-sedimenttwo-phaseflow,thebasicmodelequationsforclearwaterflowandsediment-ladenflowarededucedinthegeneralcurvecoordinatesfornaturalwatervariable-densityturbulentflow.Fur-thermore,correspondingboundaryconditionsarealsopresentedinconnectionwiththecompositionandmovementofnon-uniformbedmaterial.Thetheoreticalresultsareappliedtothecalculationofthefloatopencaissonintheconstructionperiodandgoodresultsareobtained.

简介：AccordingtotheresultsofthewaterandsedimentregulationsoftheYellowRiverinyear2002—2007,theeffectoferosionanddepositiononthelowerreaches,theamountanddistributionoferosionanddepositionintherivermoutharea,theadjustmentofriverregime,theeffectofriverregulationprojectsandchangesofflowingcapacityofthechannelareanalyzed.Itisrevealedthatthewaterandsedimentregulationisefficienttoreducedepositionandimprovetheflowingcapacityandtheconditionsofsedimenttransport.

简介：微地形学;小地貌是影响分开，运输，和流量的侵蚀过程的高地区域的一个重要表面特征。然而，很少量的信息都不关于在微地形学和沉积产出的表面之间的关系是可得到的。实验室降雨模拟研究被进行为四不同侵蚀决定易受影响的土壤在微地形学和沉积各在0.75h持续时间和60公里h^-1紧张的一系列6～8暴风雨期间产出的表面的变化。选择的土壤是Grenada的Ap材料sil(GlossicFragiudalfs)，Atwoodsil(TypicPaleudalfs)，和Forestdalesicl(TypicOchraqualfs)，以及C材料，Glauconitic沉积，Rustonsil(TypicPaleudalfs)。土壤床与一个像苗床的表面条件在斜槽被准备。在所有前并且在每暴风雨以后，表面微地形学用激光microreliefmeter被决定。微地形学;小地貌，以吝啬的本地地志的坡度，和流量数据表示了在四土壤之中显示一个很类似的模式。沉积集中的开始快速的增加，它快速到达了最大值然后逐渐地减少了到一个近的常数在暴风雨系列的结束珍视的数据表演。沉积产量仔细由于近经常的流量率跟随了沉积集中趋势。微地形学在第一暴风雨期间，但是然后很快改变了的表面减少了对为大多数在顺序的以后的暴风雨的近似经常的价值更渐渐。在沉积yield-microtopography关系中的三个不同阶段被认出：(1)preponding分阶段执行，(2)增加池溏的沉积产量分阶段执行的一根柱子，并且(3)一根柱子减少池溏的沉积收益阶段。这些阶段在粗糙驱散，小河发展，和土壤表面的土壤侵蚀过程的相对重要性反映变化矩阵稳定。

简介：Thehydraulicandsedimentdepositionproblemsinthewaterintakesystemofapumpinghousewerestudiedbyphysicalmodel.Theexperimentalresultsofdifferentworkingcasesindicatethatthesedimentdepositionsatthegates,stillingbasinandculvertsareveryfewwhenthesystemwasnormallyoperated,butintheforebayofpumpinghouse,especiallyinthepumpinghouseforlivingwater,theamountofsedimentdepositionsometimesisconsiderablylarge.Atthefrontoftheentryofpumpinghouseforlivingwater,installingasetofobliquepipescanpreventthecoarsegrainstoenterit,thedepositionamountwillobviouslydecrease.

简介：WaterandsedimentqualitiesarestudiedbyanalyzingsamplestakingfromthemouthsoftheHaihe,Duliujian,NewZiyaandBeipairiversintheHaiheriverbasininnorthChinain2005and2001,inordertofindthechangesofwaterandsedimentpollutions.Theconcentrationsofheavymetals,arsenic,totalnitrogen(TN)andtotalphosphorus(TP)areanalyzedandresultshavebeencomparedforthetwotimes.Thein-situmeasurementforDissolvedOxygen(DO)andSedimentOxygenDemand(SOD)rateswerecarriedattheHaiheandDuliujianrivermouthsin2006.Theresultsshowthatthewatersofthe4rivermouthsarestillseriouslypolluted,thoughmuchimprovedinthecaseoftheHaiheandDuliujianrivers.ThemainpollutantsareTPandTNintheNewZiyaandBeipairiversandmercury(Hg)atall4rivermouths.Comparedwiththosein2001,theconcentrationsofalmostallmetalsandarsenicinthe4rivermouthshavedecreased.WaterqualityatHaiheandDuliujianshowsanimprovingtrend,whilethewaterqualityatBeipaiissimilartothatof2001.Incontrast,waterattheNewZiyarivermouthismoreseverelypolluted.Thesedimentsinthe4rivermouthsarenotseriouslypollutedbyheavymetalsbutarepollutedbynitrogenandphosphorus.Mostofthepollutantcontentsinthesedimentsshowlittlechangebetween2001and2005.Thein-situDOandSODmeasurementshowsthatthewatersattheHaiherivermouthisinthestateofoxygendepletion,andSODisimportantconsumerofDOattherivermouths.Theoverallanalysisshowsthatincreasingwaterpollutionandeutrophicationinwatersfarfromcitiesareongoingcausesofconcern.

简介：Basedonthe2-DflowandsedimentnumericalmodeloftheYangtzeEstuaryandtheHangzhouBay,thecharacteristicsofwaterandsedimentexchangeintheirjointwatersisstudiedthroughquantitativecalculationandanalysisofthecharacteristicsofwaterflowandsedimenttransportation.Theresultsshowthatthereisperiodicalwaterandsedimentexchangeinthisjointwaters,thatthenetwaterexchangeappearsmainlybetween0～6mdepth(theoreticaldatumplane,thesamebelow)offshoreandthemaximumisnearthedepthof2m,andthatthenetsedimentexchangemainlyappearsbetween0～5mdepthandthemaximumisnearthedepthof3m,indicatingthattherangeofwaterflowpassageisdifferentfromthatofsedimenttransportfromtheYangtzeEstuarytotheHangzhouBay.Combinedwiththeresultsofnumericalsimulation,thispaperalsoanalyzesthehydrodynamicalmechanisminfluencingwaterandsedimentexchangebetweentheYangtzeEstuaryandtheHangzhouBay,includingtidalfluctuation,tidalcurrentkineticenergy,tide-inducedresidualcurrentandthetraceofwaterparticles.Finally,thesedimenttransportationpassageontheNanhuitidalflatisdiscussed,andtheresultsshowthatsedimentistransportedintotheHangzhouBayfromthesouthsideofShipilei,whilesedimentisbroughtbacktotheSouthChanneloftheYangtzeEstuaryfromthenorthside.

简介：三巡航在2005在珍珠河河口(PRE)被发射调查与与有机物的降级有关的早成岩作用联系的营养素骑车的biogeochemical。在沉积的毛孔水营养素集中和侧面模式的季节、空间的变化被学习。在沉积水接口(SWI)的滋养的流动被孵化实验测量，并且我们这里在SWI讨论了营养素的累积和转变过程。营养素通常下游地从珍珠河插头减少了，显示对在河口的滋养的输入的人为的影响。NO3-N集中在overlying水里吵闹(溶解的无机的氮，NH4-N的和，NO3-N和NO2-N)的三种形式中是最高的，并且NH4-N是毛孔水里的吵闹的主要部件。NH4-N的渐渐的增加和有沉积深度的NO3-N的快速的减少在SWI下面为厌氧的条件提供了证据。NO3-N的否定流动和NH4-N的积极流动通常被观察，建议在SWI的NO3-N的denitrification。吵闹流动方向建议然而，沉积是在春天的吵闹的水池沉积通常是在夏天和冬季的吵闹的来源。当SiO4-Si不显眼地在不同季节在沉积侧面变化了时，PO4-P分发模式是不同的。当SiO4-Si主要从沉积扩散了到水列时，流动结果显示了主要从水列传播到沉积的那PO4-P。通常，孵化流动是联合散开，bioturbation和生物化学的反应，并且在这研究是相对精确的。

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简介：这份报纸在水分泌物的时间系列和黄河的沉积负担检验变化进Bohai海。为了决定突然的变化的特征和水的多尺度的时期，分泌物和沉积装载，从Lijin的数据车站被分析，并且回声时期当时是计算的。Mann-Kendall测试，聚类的顺序，力量光谱，和小浪分析被用来在最后62年观察水分泌物和沉积负担进海。在进海的水分泌物的最重要的突然的变化在1985发生了，并且在沉积负担的一个突然的变化发生在一样的年里。分别地，64.6%和73.8%的重要减少在1985前在水分泌物和沉积负担被观察。在水分泌物和沉积负担的更重要的突然的变化在1968和1996被观察。进Bohai海表演的水分泌物和沉积负担的特征在内部年度、十的规模的周期的摆动。而沉积负担的主要经期是10.67年，4.27年，和2.78年，水分泌物的主要经期是9.14年和3.05年。在水分泌物和沉积负担之间的重要回声时期在下列时间的规模被观察：2.86年，4.44年，和13.33年。水分泌物和沉积负担开始在1970以后减少并且自从1985，为几个原因显著地减少了。第一，黄河排水区域的降水后来减少了1970。第二，大规模人的活动例如水库和制约的大楼，增加了。第三，自从1985，水和土壤保存生效了。

简介：NitrogenandphosphoruscontentsareanalyzedintheoverlyingwatersandporewaterstakenfromtheChangjiangEstuaryandShanghaicoastaltidalflatsinthisstudy.Inaddition,thediffusionfluxesofnitrogenandphosphorusacrossthesediment-waterinterfaceintidalflatsareestimatedaccordingtothenutrientconcentrationgradientsattheinterface.Ithasbeenindicatedthattheconcentrationsofammonium,nitrite,nitrateanddissolvedphosphorusinoverlyingwatersrangefrom0.0082～2.56,0.03～0.58,0.69～5.38and0.035～0.53mg/L,respectively,while0.0025～1.35mg/LforNH4+-N,0.0055～0.20mg/LforNO2--N,0.61～1.14mg/LforNO3--Nand0.11～0.53mg/LforDPinsurfaceporewaters.Thefindingshaverevealedthatammonium,nitrite,nitrateanddissolvedphosphorusdiffusionfluxesacrossthesediment-waterinterfacearebetween-0.024～0.99,-0.39～-0.0019,-3.09～thesourceofphosphorusandanimportantsinkfornitrogeninthewaters.

简介：SurfacesedimentsamplestakenfromtheEastChinaSeaofftheChangjiangestuaryareusedasrawmaterialsforphosphorusreleasingexperiment.Itisfoundthatafterbeingthoroughlymixedwithseawaterforabout10minutes,phosphorusreleasedfromthesedimentsreachesitsmaximumvalue.AdsorptionkineticscanbefittedwithbothElovichequationandtwo-constantrateequation.Thereleasingamountiscloselyrelatedtothecompositionofthesediments.Phosphorusreleasefromsiltyandmuddysedimentishigherthanfromthatdominatedbysandycomposition.Forthedesorptionreaction,iron-phosphorus(Fe-P)isthemostactiveone,withareleasingratiohigherthanotherphosphorusforms,followedbyabsorbed-phosphorus(Ad-P)andorganicboundphosphorus(OP).Allofthemcanbereferredtoasbio-availablephosphorus.Theresultsdemonstratethatphosphorusinsedimentscanbereleasedintoseawaterundersuitablehydrodynamicconditions,andhaveagreatimpactonthenutritionstateandprimaryproductivityofmarinebiosphere.

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简介：话题呈现水是万物之源,没有水,人类和动物就无法生存。因此,人人都有保护水资源和节约水资源的职责。某期刊正在开展以水为主题的征文活动,请你根据下面的信息写一篇短文参加征文。短文内容包括水的重要性、水的用途、水的现状及我们该如何保护水源和节约用水。