引黄灌区不同类型渠道冲淤特性分析

以簸箕李和位山两灌区实测水沙资料为依据，分析了不同类型渠道（沉沙条渠、衬砌渠道、土质渠道和支斗渠）的冲淤特性以及引黄含沙量和粗颗粒泥沙对渠道冲淤的影响；指出，冲淤交替是渠道冲淤的基本特性之一，灌区工程改造是影响冲淤的主要因素之一；提出了变比降沉水条渠泥沙冲淤模式。     

东洞延湖冲淤平衡水位初步分析

在天然河道水流中,来水来沙的一般特性是汛期流量大、含沙量大、粒径小、水面比降大;枯期流量小、含沙量小、粒径粗、水面比降小.河段泥沙冲淤平衡有可能随时发生,某一水位可能冲淤平衡,也有可能冲淤不平衡,不存在所谓稳定的泥沙冲淤平衡水位.在湖泊水网区的河道水流中,其水文和泥沙特性明显不同于一般的天然河道.一般而言,它汛期是湖,枯水是河,相应出现汛期淤积,枯期冲刷,冲淤同水位过程有十分密切的关系,有可能存在一个比较稳定的泥沙冲淤平衡特征水位.在这种河湖两相的河道水流中,研究泥沙冲淤平衡特征水位较之研究与造床流量相应的水位更有其重要的实际意义.本文对东洞庭湖的泥沙冲淤平衡特征水位进行了初步探讨,认为东洞庭湖区河道水流中,存在一个泥沙冲淤平衡特征水位,并就1984、1980、1975、1970年的水文泥沙资料进行了计算.     

闹德海水库泥沙冲淤数学模型

为了研究水库延长蓄水期后引起的库区泥沙问题,在详细分析了闹德海水库泥沙冲淤演变规律的基础上,研制了闹德海水库泥沙冲淤数学模型,并对模型进行了验证。     

太湖湖盆泥沙问题的研究

本文研究了太湖湖岸、湖床的演变，湖流及湖区泥沙冲淤特性。研究表明，风浪在湖区沙量分布上起着重要作用，而风成湖流是湖区泥沙输移的动力。本文还建立了简化的湖区泥沙冲淤模型。初步计算表明，平台山以南的沙埂系风成流沉积体。东太湖的泥沙淤积是风成流和吞吐流共同作用的结果，东太湖湖周及新淤滩地沼泽化与泥沙组成关系密切。     

桃河阳泉城区段泥沙冲淤情况分析

文章利用不同年代实测资料，通过多年泥沙演变分析，研究桃河河道泥沙冲淤变化情况，推理分析桃河泥沙冲淤规律。     

黄河龙门至河口水文学泥沙冲淤数学模型

本文概述了黄河龙门至潼关，三门峡至利津及利津以下河道水文泥沙冲淤计算方法，并用１９６０－１９９０年这测资料对模型进行了验证计算，结果表明，分时段、分河段泥沙冲淤量计算值与实测值吻合较好，累积冲淤过程比较一致。     

1994年汛期三门峡水库运用情况及冲淤特点

通过对三门峡水库１９９４年汛期各阶段的水沙条件，运用情况，冲淤变化和水沙调节等特点进行汛期排沙与发电应分阶段运用，并根据水沙变化和库区冲淤情况适时调度、合理调水调沙的运用方式，有利于库区泥沙冲淤平衡，降低潼关高程，减少过机泥沙，提高发电效益。     

拦减粗泥沙对黄河下游河道冲淤的影响

近２０年，黄河的来水来沙发生了变化，粗泥沙来量也有所减少，这些变化对水库和河道冲淤都将产生很大影响。本文以研究不同级配泥沙移特性和冲淤市场信息灵基础，分析不同地区来水来沙对水库和下游河道的影响，三门峡水库正常运用对粗细泥沙的调节作用，以及下游不同河段各粒径级泥沙沿程调整过程，拦粗泥地下游中淤的影响，为水库制定合理运用方式及下游防洪减淤治理决策提供依据。     

立交地涵泥沙问题实例研究

通过数值计算，模型试验和现场观测，对通榆河与灌溉总渠渠立交地涵的泥沙淤积进行了综合分析，结果表明，无论采用何种设计方案，地涵洞身的淤积量均不大。为安全起见，采用水力冲淤是行之有效的防淤，减淤措施。     

泥沙数学模型在黄河下游防洪规划中的应用

黄河下游河道的冲淤变化是制定上游防洪规划措施的一项重要依据，黄河下游河道泥沙数学模型是研究下游河道冲淤变化的重要手段。利用多个泥沙数学模型对不同水沙系列以及小浪底水库不同运用方式条件下下游河道的冲淤变化进行了分析计算，预测了2020年以前下游河道的冲淤变化。     

共青河泄洪闸除险加固工程试验研究

共青河泄洪闸下游河道由于人为过量挖沙导致下游河床下切、水位降低 ,泄洪闸泄洪造成了下游左堤岸决堤。共青河泄洪闸除险加固工程方案的试验研究表明 ,在泄洪闸原消力池下游设置二级消力池 ,能较为妥善地解决消力池出流与下游河道水流衔接过渡的问题。     

海河口闸下泄流拖淤分析

海河口属淤泥质河口，其档潮闸下引河淤积问题极为严重，挖泥清淤虽然有效，但费用之高愈来愈连以承受，利用闸上有限泄流或闸下落潮流拖淤，寻找一种简捷，经济的清淤措施已引起海河流域水管部门的极大兴趣，本文对１９９４年海河干流挡潮闸下拖淤情况进行了全面的介绍和分析。     

潮州供水枢纽西溪拦河闸下游水位下降影响研究

近年来,由于潮州供水枢纽西溪拦河闸下游河床下切、下游河道水位下降,对枢纽工程运行产生了不同程度的不良影响。对此在对历年西溪拦河闸下游河道水位与流量关系变化总结和分析的基础上,对下游河道水位下降对西溪枢纽拦河闸、电站、船闸等建筑物的影响进行分析,介绍枢纽工程现行采用的改造工程措施,并对今后改造的方法进行探讨,供工程设计和运行参考。     

曹娥江口门建闸闸下尖山河段河床变化预测研究

根据钱塘江河口实测水下地形资料和水文资料分析，在河口段支流曹娥江口门建闸后，其闸下河床面貌主要取决于钱塘江河口尖山河段主槽的位置，并通过类比法等方法预测了尖山河段达到规划线后的曹娥江口门建闸闸下最不利的河床面貌。     

清远水利枢纽消能防冲问题试验研究

消能防冲是枢纽的安危所系,由于清远水利枢纽工程所处的北江下游河道受人为采砂的影响,河道水位连年下切,枢纽的消能防冲设计受到高度重视。对此利用宽水槽断面模型,在定床模型试验研究中对消能工体型进行多方案优化并确定了推荐方案,在下游局部动床试验中对推荐方案在各种工况下的闸下冲刷情况进行研究,分析消能防冲设计的安全性及可靠性。试验研究解决了该平原河道大型水闸枢纽消能防冲的关键技术难题,试验推荐方案为工程设计所采纳。研究成果可供平原河流大型水闸枢纽消能防冲设计借鉴和参考。     

Effective Optimization-Simulation Model for Flood Control of Cascade Barrage Network

In this study, a novel simulation-optimization model for the optimal flood control of the cascade barrage network was proposed by combining a simulation-based optimization method with a one-dimensional flood numerical analysis method. The simulation-based optimization method determines the optimal operation rules of cascade barrages, including the pre-discharge stage algorithm and the main-discharge stage algorithm for the securement of flood control storage and the establishment of a minimal discharge plan. The optimal operation rules describe the detailed operation process of barrage floodgates including full and partial opening and provide the upper and downstream boundary conditions for the flood numerical analysis method, which evaluate the flood propagation in the river channel between barrages. The proposed model was applied to the flood control of the six-cascade barrage network in the Taedong River, Democratic People’s Republic of Korea, and its effectiveness was verified in comparison with a well-known PSO-optimization method. The results show that the proposed model is superior to the existing other method and practically applicable to the flood control in the rivers with cascade barrage network.

     

Effect of New Nag Hammadi Barrage on Groundwater and Drainage Conditions and Suggestion of Mitigation Measures

The government of Egypt has decided to construct a new barrage with hydropower facilities, 3.5 km downstream of the existing old one. The water levels in the head pond for the new barrage will be continuously maintained at a level with approximately 0.5 m higher than water level in the head pond of the existing one. To evaluate the effect of increasing the head pond water level on the groundwater and drainage, there is a need to enhancelinking reservoir and stream/aquifer system. Visual MODFLOW hasbeen used to simulate the surface water/groundwater interaction in the area of proposed new barrage. The model has been calibratedagainst the available historical groundwater levels for 25 observation wells based on the steady state conditions. Numerical modeling suggests that river stage is the primary control of rapid groundwater hydraulic head fluctuations in theaquifer system. At present the area at which the depth to groundwater table less than one meter is about 30 110 feddans (1 feddan = 4200 m²). This area will increase to be about40 610 feddans after the construction of the new barrage and increasing the head pond water level. The mitigation measures toovercome the effect of construction of the new barrage have been discussed and their costs have been estimated and evaluated. Increasing the efficiency of existing drainage system by maintenance/upgrading and constructing a new pump station is recommended.     

乐昌峡水利枢纽拦河坝放水底孔施工技术的应用

放水底孔是乐昌峡拦河坝施工中的关键部位,上下游牛腿距离地面悬空高度11 m以上,选用贝雷架作为施工的承重平台及操作平台。进水口段为弧形,对外观要求较高,为获得良好的施工效果,采用异形定制钢模板保证放水底孔的外观,并进行合理的砼浇筑分层施工,优化施工组织,保证砼的浇筑质量。     

不规则实体堰坝流场及应力场耦合分析

针对现有堰坝稳定计算方法存在模型概化简单,无法准确反映不规则堰坝的流场及应力分布的问题,基于有限元软件ANSYS Workbench,通过引入气液两相流来求解堰坝的表面流场和水压力,将流场计算结果耦合到结构力学分析中实现某不规则实体堰坝的应力及变形分析。计算结果表明,设计洪水位和常水位工况下堰坝压应力均满足地基承载力要求,且堰体内部未出现拉应力;堰坝整体变形分布合理,能很好地反映堰体与基础非连续性的变形情况。该方法可有效地解决堰坝三维形态复杂及表面压力分布不均所带来稳定分析困难,可为堰坝设计提供依据。     

Zooplankton population in the river tigris: Effects of samarra impoundment

The influences of the Samarra impoundment on the ecology of the downstream sector of the river Tigris are investigated. Zooplankton were collected monthly from July 1987 to July 1988. It was found that zooplankton were most abundant during high river discharges in March. During the month of low river discharge, September, the zooplankton population was greatly reduced immediately below the barrage and remained so to the last downstream station. Several factors seem to explain such differences. The high discharge from the impoundment was found to be the dominating factor and may flush the small backwaters in which zooplankton were abundant, thus increasing the population in the river. Zooplankton species vary in their ability to sustain populations in the river, variations which are due mainly to species-specific characteristics.