A NUMERICAL MODEL OF SEDIMENT TRANSPORT IN HANDUN IRRIGATION DISTRICT

LABRIEFINTRODUCTIONOFRANDUNIRRIGATIONDISTRICTYellowRiverisoneofthemainWaterresourcesinNOrthChina.SincethefiftiesirrigationbydivertingwaterfromtheYellowforerdevelOPssteadily.AstheYdlowforerisaheavilysacmentsladenone,sedimentisdiVertedsimultaneouslywhenwaterisdiverted.HOwtoproperlytreatthedivertedsedimentboomesoneOfthekeyproblemsrestrichngthesustainingdevelOPmentofthCwaterresourcesinthatarea.LongchStanceconvopngsedimentisoneofthemainmeasuresfordealingwiththediVertedsedim…     

ALTERATIONS OF RIVER MORPHOLOGY DUE TO VEGETATION ON SLOPES AND FLOOD PLAINS

LRESEarCHACTIVITIESCharaCtCriedcofunlinedalluvialriVersisthe~linteractionbettVeenwaterflowandmovableriVerbed.Sedimenttransport,bedresistanceandriVermorphologydecisivelydependontheflowconditionsandviceversathesefactorsgovernthehydraulicprocesses.EVenundersimplifiedconditions,e.g.inlaboratorytests,theseillteractionsareeXtremelycomplexandrelldsraliZationmakesengineeringproblemsevenmored~.TomaketheseprocessesmoreunderstandablecomprehensiVeresearchprojectswereconductedatseveralGermanuniv…     

EROSION CONTROL AND RESOURCE MANAGEMENT ON UPLAND WATERSHEDS OF GRANITIC REGION

I.FEATURESOFSOILEROSIONINGRANITICREGIONS1.1IntroductionGuangdongProvinceislocatedinsubtropicalzoneandthenorthernborderofthetropicalzone.ThelatitudestCtchesfrom20'07'to25'31'N,thelongitudefrom108'33'tO117'20'E.Subtropicalclimateprevailsinmostoftheprovince.Theannualaveragerainfallis1500-1800mm,withstrongintensityandun-evendistribution.Thedeifyrainfallduringwnhoonstormsmayreach200-300mm:Thetotallandareaisabout178,100sq.km,inwhich25,100sq.kmarecultivated.12,000sq.km,6.7%oftotalP…     

由单Doppler雷达资料反演水平风场的简单共轭函数方法的改进方案

该文改进了Qiu和Xu提出的由单个Doppler雷达探测的资料反演水平风场的简单共轭（simple adjoint）函数方法。其基本做法是将控制方程中的状态变量改用其时间距平量代替，并加入一待反演的方程误差项。利用1988年夏季在美国丹佛机场所作的一次下击暴流的双Doppler雷达观测试验资料对新方法作了检验，结果表明其对反演结果的改善是显著的。     

MASINGA RESERVOIR IN KENYA：SEDIMENT DISCHARGE AND IMPLICATIONS FOR ITS CAPACITY

ＭＡＳＩＮＧＡＲＥＳＥＲＶＯＩＲＩＮＫＥＮＹＡ：ＳＥＤＩＭＥＮＴＤＩＳＣＨＡＲＧＥＡＮＤＩＭＰＬＩＣＡＴＩＯＮＳＦＯＲＩＴＳＣＡＰＡＣＩＴＹ￥Ｆ．Ａ．Ｏ．Ｏｔｉｅｎｏ（ＳｅｎｉｏｒＬｅｃｔｕｒｅｒｉｎＣｉｖｉｌＥｎｇｉｎｅｅｒｉｎｇ，Ｕｎｉｖｅｒｓｉ...     

地壳形变,震灾对策与地震预报研究的现状和发展动向

简要地概述了地壳形与大陆动力学，防震减灾对策与地震预报研究领域中的现状和发展动向。     

鲍尔曼特—爱德华兹Pb-Zn矿床——密西西比型流体同生沉积

前言纽约西北鲍尔曼特—爱德华兹(Balmat-Edwards)pb-Zn 矿赋存于中元古代格伦维尔系碳酸盐和钙—硅酸盐大理岩中,从1915年此矿发现以来,虽然由于遭受过高级角闪岩变质作用从而导致矿床成因复杂化,但对于它们的形成模式和时代问题已经有了相当的研究。尽管最早的研究者提出过诸如高温岩浆成因和(或)变质成因见解,但现在一般认为矿床的就位是在变质作用之前。这项研究工作包括了福勒(Fowler)矿体矿石和脉石的硫、碳和氧同位素分析,     

大气稳定度和城市热岛对都市——郊区的风速的影响

调查伦敦附近和一些地区逐时风速的作用。在于确定不同季节里每天的大气稳定度的变化,和城市热岛对都市——郊区风速不同的影响。对都市与郊区风速作比较,存在一种“临界”风速,在“临界”风速以下,都市风速很快,在“临界”风速以上,都市风速很低。当局地风速很高时,都市表面的摩擦作用是主要因素,不过,在局部空气流动轻微的情况下,郊区大气很稳定,同时城市热岛也强烈发展,在城市大气很不稳定时,动量的传递可以增大到达地表,这样,在城市内就保持很高的风速。     

RATIONAL BASIS FOR SUSPENDED SEDIMENT MODELING

This paper presents a rational basis to model the transport of suspended sediment. The loose-boundary condition for 3D models and the adjustment coefficients for both the depth-integrated 2D and laterally integrated 1D models are treated comprehensively. A combination of Dirichlet and Neumann conditions is proposed as the loose-boundary condition. The adjustment coefficient for 2D models is obtained on the basis of the proposed boundary condition and analytical solutions developed for some simple cases of non-equilibrium transport of sediment in uniform flows. The adjustment coefficient for 1D models for natural rivers is further obtained from lateral integration. Comparisons with analytical solutions and a considerable amount of laboratory and prototype data show that mathematical models developed along the proposed line of attack would well simulate the transport of suspended sediment in practical problems.