Sediment flux from Lesser Zab River in Dokan Reservoir: Implications for the sustainability of long‐term water resources in Iraq

Prudent management of Iraqi water resources under climate change conditions requires plans to be based on actual figures of the storage capacity of existing reservoirs. With the absence of sediment flushing measures, the actual storage capacity of Dokan Reservoir (operated since 1959) has been affected by the amount of sediment delivered during its operational life leading to an undetermined reduction in its storage capacity. In consequence, there has not been an update on the dam's operational storage capacity curves. In this research, new operational curves were established for the reservoir based on a recent bathymetric survey undertaken in 2014. The reduction in reservoir capacity during the period between 1959 and 2014 was calculated by the mean of the difference between the designed storage capacity and the storage capacity which was concluded from the 2014 bathymetric survey. Moreover, the rate of sediment transported to the reservoir was calculated based on the overall quantities of accumulated sediment and the water discharge of the Lesser Zab River into the reservoir. The results indicate that the dam capacity is reduced by 25% due to sedimentation of an estimated volume of 367 million cubic metres at water level 480 m.a.s.l. The annual sedimentation rate was about 6.6 million cubic metres, and the sediment yield was estimated to be 701.2 t?km^?3?year.     

巴家嘴水库库容测量与防洪安全复核

巴家嘴水库为多泥沙河流水库,淤积问题较为突出。2019年实测兴利库容仅为2008年的20%,总库容约为2008年的67%,略大于2004年加固设计报告计算的2038年库容,淤积十分严重。文章在库容测量与泄流能力复核基础上,对大坝防洪能力进行了复核计算,提出了水库调度运用方式,以延长水库使用寿命。     

我国水库淤损情势分析

基于全国第一次水利普查水库资料,分析了我国水库时空分布特征,我国现有10万m3以上的水库约9.8万座,总库容约9323亿m3,其中小型水库数量占全国的95.22％,大型水库库容占全国的80.43％,我国水库数量和库容在1950年以后快速增加.在掌握全国水库分布的基础上,收集了我国6702座水库淤积资料,其中约90％的水...     

小浪底水库对泺口至利津河段冲淤变化分析

根据小浪底水库2002~2015年的调水调沙资料,对泺口至利津河段的冲淤情况进行分析,认为调水调沙使泺口至利津河段的河道得到明显冲刷,主槽断面形态向良性发展,平滩流量大幅增加,过流能力大大增加。同时近几年调水调沙资料表明河道冲刷力度减弱,冲刷效率降低,河床粗化,主槽过流能力已基本稳定。     

珠江口伶仃洋深水航道开发方案的回淤研究

根据伶仃洋的潮流、含沙量及水下地形的变化特点，对黄埔出海航道在伶仃洋的选线方案作了分析计算。选用泥沙回淤计算公式预报了各航道开挖后的回淤量。用伶仃西航道和蛇口五湾航道开挖后的实测结果进行淤积验证，计算值与实测值符合较好。伶仃东航道泥沙的回淤量少于伶仃西航道；铜鼓东航道也少于铜鼓西航道。无论开发伶仃东航道或是在伶仃西航道原来的基础上加深，均为可行。     

西丽水库泥沙问题及对策分析

西丽水库是深圳市最重要的供水水库之一，随着周边区域开发的加剧，泥沙淤积和底泥对水质的影响已不容忽视。阐述西丽水库目前的泥沙淤积情况及底泥污染状况，并分析探讨应采取的对策。     

潍坊港扩建工程方案泥沙淤积研究

利用现场实测资料及现有的研究成果，对潍坊港扩建工程的方案、港口泥沙淤积、河口演变、港址选择和挡沙堤长度等问题进行分析论证，首次提出平衡水深的概念，并用以预报不同方案的港池和航道淤积量，最后推荐港口扩建工程的最佳方案。     

涌潮条件下排桩式低丁坝水力学冲淤试验研究

本文在水槽中用动床模型试验手段研究了涌潮条件下不同透水率的排桩式护塘低丁坝群的水力学冲淤特性，并探讨了低丁坝的护滩保塘机理，结果表明，不透水的排桩式丁坝群，其坝田部位可减冲1-1.6m，与相应方案的堆石坝研究结果相近；随着板桩丁坝透水率的逐渐增大，滩地防冲作用逐渐变小，然而透水率大于60%的丁坝，仍有0.8m以上的减冲能力，低丁坝的保滩护塘机理主要体现在三个方面；即对涌潮潮头的阻挡作用，对涌潮快水的减冲作用和在落潮期回流淤积作用。     

黄河艾山以下河道引水引沙与河道冲淤关系的分析

本文通过实测资料分析，研究引水沙与河道冲淤的关系，明确引水引沙对河道的影响提出合理的引水引沙方案，并研究利用引水引沙减少艾山以下河道淤积措施的可能性。     

考虑船舶停靠的码头减淤措施研究

目前,码头淤积和减淤措施的分析计算中,很少考虑船舶停靠的影响。针对金塘水道某码头,建立二维潮流泥沙模型,数值计算得到的潮流、含沙量结果与实测结果吻合。进而分析船舶停靠对潮流水动力和码头冲淤变化的影响。计算结果表明:船舶停靠阻碍了潮流运动,导致流速减小和泥沙淤积,但影响仅为周边区域。在考虑船舶停靠频率不变的前提下,针对目前1#,2#泊位最大月淤积强度接近实测淤积量（＞1.15 m）这一情况,提出了3种减淤方案,并计算了实施方案1后的潮流和冲淤变化,发现导堤长度对减淤效果影响很大。对于重淤区而言,基于综合分析比较,短堤的防淤减淤效果较好,故推荐采用短堤方案。     

Groundwater use and policy options for sustainable management in Southern Iraq

An important challenge facing the design of sustainable aquifer management plans is weak primary data on aquifer recharge and use patterns. Weak data limit the ability of policy makers to design efficient aquifer protection plans. The objectives of this article are (1) to estimate groundwater use patterns for an important food-producing region of southern Iraq, the Bahr Al-Najaf Basin; (2) to compare groundwater use patterns with the renewable groundwater supply; and (3) to describe a sustainable groundwater policy alternative to current use patterns. For this study, original data on groundwater pumping were secured for 2006–2011. The data show a pattern of unsustainable groundwater withdrawals. A policy intervention is described in which pumping permits could be assigned to groundwater users to promote sustainable use. Allowing or encouraging the permits to be transferable through trading to higher-valued uses could reduce the economic costs of protecting the aquifer while promoting its sustainable use.     

水库库容淤积DEM图制作与分析

为准确掌握水库库容淤积及分布情况,以佛子岭水库为例,利用GIS对不同时期的库区地形图进行数字化建模,计算水库的库容和淤积量,并通过数字模型叠加计算制作水库库容淤积分布DEM图。结果表明：库容淤积DEM图直观地反映库区地形淤积厚度和分布情况,佛子岭水库库区淤积主要发生在死库容区域,纵向形态为带状淤积,没有明显的凸起和锥状淤积现象,横向呈现沿湿周的均匀淤积。准确掌握水库库容及淤积变化情况,为水库运行规范化管理、防洪调度提供重要技术支撑。     

溪洛渡、向家坝水库与三峡水库联合蓄水调度研究

由于溪洛渡、向家坝水库与三峡水库蓄水时间上的同步性,使三峡水库蓄水难度进一步加大,进而影响其综合效益的发挥。为满足下游地区在蓄水期对上游梯级水库下泄流量的新要求,研究金沙江溪洛渡、向家坝水库与三峡水库联合蓄水调度方案,优化梯级水库蓄水过程。在综合分析防洪、泥沙、库区、发电及供水等指标基础上,推荐梯级水库蓄水调度方案。防洪、库区淹没及泥沙淤积的影响分析表明,所提方案可进一步缓解下游地区的供水压力,对金沙江梯级水库联合蓄水调度一定实践指导意义。     

水沙变化对渭河下游河道淤积和纵剖面的影响

将渭河下游按照纵比降变化情况分为上、中、下三段，分别是陡坡段、过渡段和缓坡段，认为沿程冲淤会影响整个河段，溯源冲淤主要影响中、下段；1990年以来渭河下游的持续堆积主要是由来水来沙变化引起的，持续淤积使潼关高程持续抬高，从而也加重了渭河下游中、下段的淤积；并与黄河下游纵剖面的变化进行了对比。     

西霞院水库闸前泥沙防淤堵设计

西霞院水库泄水建筑物采用集中布置方案,从左岸依次设置3条安装间排沙洞、3条位于机组中间的排沙底孔、3条排沙洞、7孔胸墙式泄洪闸、12孔开敞式泄洪闸及王庄引水闸2孔.闸前排沙洞、排沙底孔事故门冲淤系统主要由自吸泵、管路、阀门及仪表等组成,借鉴了黄河调水调沙试验中人工扰沙的经验,解决了闸前淤积问题.     

超高面板坝淤填自愈型止水结构可行性的初步研究

通过有限元计算和复变函数推导，系统研究了面板接缝的渗流规律，给出了接缝渗流量和渗透比降的解析计算公式，可用于面板堆石坝接缝渗流控制的设计。同时结合233m高的水布垭面板坝，对淤填自愈型止水的渗流控制效果及在超高面板坝中应用的可行性进行了计算分析。     

Mechanism of back siltation in navigation channel in Dinh An Estuary,Vietnam

The Dinh An Estuary is one of the Nine Dragon estuaries of the Mekong River. An international navigation channel was built in the estuary for vessels traveling from the South China Sea to the southwestern area of Vietnam and then to Phnom Penh, Cambodia. The morphological evolution of the navigation channel is complicated and unstable. The back siltation intensity in the navigation channel has largely increased and been concentrated in the curvature segments of the channel since 1980. In this study, based on simulation results and measured data, five key factors that influence the back siltation in the navigation channel were systematically analyzed. These factors included the increasing elevation gap between the channel and the nearby seabed, the disadvantageous hydrodynamic conditions, sediment transport, mixing of saltwater and freshwater, and wave effects in the navigation channel. It is shown that the back siltation to a large extent results from the low current velocity of the secondary ocean circulation, which often occurs in the curvature segments of the channel. Suspended sediment also settles in the channel due to the decrease of the current velocity and the sediment transport capacity when flow passes through the channel. The changes of hydrodynamic conditions are responsible for the majority of the severe siltation in the curvature segments of the navigation channel.     

小浪底水库运用情况分析

对小浪底水库下闸蓄水至2005年的运用情况进行了分析,并将运用效果与设计成果进行了对比,结论认为：①水库自投入运用至今均处于拦沙初期运用阶段;②水库运用以来,干流淤积三角洲顶点位置随着库水位的变化逐步向下游推进;③库区淤积形态与设计淤积形态相比,总体看来淤积部位偏上游,但未侵占长期有效库容;④库区泥沙主要以异重流形式输移,排沙比与设计成果基本一致;⑤从目前支流纵剖面形态看,各支流均未形成明显的拦门沙坎,随着库区淤积量的不断增加及运用方式的调整,拦门沙将逐渐显现。建议今后加强对支流纵剖面、异重流倒灌和水库冲刷的观测,对支流拦门沙的形成及发展演变机理进行专题研究。     

潍坊北港淤积分析和模型试验

根据现场实测资料，分析潍坊北港港池冲淤和河道变化的原因，提出合理的汉道选择。并通过定床清水模型试验，确定改善港池水深的整治措施。