鲁布革电站水库进行首次空库冲沙

鲁布革电站水库进行首次空库冲沙鲁布革电站装机６００ＭＷ，水库正常蓄水位１１３０ｍ，死水位１１０５ｍ，有效库容０７４亿ｍ３，死库容０３７亿ｍ３，水库最低点为右岸泄洪洞底板１０６０ｍ。水库自１９８８年汛后下闸蓄水，８年来共淤积泥沙２０００多万ｍ３，其...     

水库冲沙

由于修建新坝会遇到很多困难，用冲走水库淤积泥沙来维持水库使用寿命的做法已起来越受到重视，回顾了水库冲沙现状，并强调了需要对水库冲沙规划进行风险分析。     

新疆克孜尔水库运行库水位对汛期排沙比的影响分析

排沙比大小直接影响上游来沙在库区的淤积。克孜尔水库库区泥沙淤积日趋增加,有效库容日益减少。通过对比分析水库系列水文观测资料,得出影响排沙比的重要因素为库水位,并对1 133-1 138 m、1 138-1 142 m、1 142 m以上3个不同运行库水位下的汛期排沙比统计分析,证明在低水位运行下,水库汛期排沙效果相对较好。     

水库冲沙

由于修建新坝会遇到很多困难 ,用冲走水库淤积泥沙来维持水库使用寿命的做法已越来越受到重视。回顾了水库冲沙现状 ,并强调了需要对水库冲沙规划进行风险分析     

三盛公水利枢纽拦河闸上游冲沙泄库初探

三盛公水利枢纽工程座落在多泥沙的黄河干流上 ,经过 4 0年的运行及近 10年来黄河连续枯水年来水量小的影响 ,库区尤其是闸前淤积问题已相当严重 ,直接威胁到工程的安全。为了泄水冲淤、输通河道、增加有效库容 ,黄管局于 2 0 0 0年 11月 7日开始实施集中来水量对拦河闸上游进行有组织、有计划集中开启 16#,17#,18#孔的冲沙泄库工作。冲沙泄库期间密切关注拦河闸上下游水位、水流形态、淤沙等的变化情况。冲沙工作已取得一定成效 ,为今后小流量冲沙工作提供了宝贵经验     

莫莫克水库敞泄冲沙泥沙模型试验分析

采用泥沙模型试验的方法在莫莫克水库运行30 a后对其开展敞泄冲沙试验研究。试验结果表明：水库运行30 a后死水位和正常蓄水位之下的库容均大幅减小,敞泄冲沙试验后水库恢复了约1 536.81万m³库容,水库冲刷量约1 521.60万t,排沙比达到579%,出库沙量呈现出由大到小的趋势,取得了较好的冲刷效果。建议在在水库基本进入冲淤平衡阶段,择机开展敞泄冲刷水库调度方式增大水库排沙比,提高水库综合效益。     

文泾水电站泄洪冲沙设计

文泾水电站位于多泥沙的泾河上,泥沙问题是直接关系到文泾水电站发电效益和安全的重大技术问题。设计采用泄洪冲沙洞作为泄洪排沙建筑物,通过计算分析、模型试验确定冲沙洞相对位置、规模,成功地解决了泥沙淤积问题,保证了电站发挥正常效益。     

山西省中部引黄工程泥沙淤积及冲沙研究

以山西中部引黄工程为研究对象,利用常观资料和工程试验资料,分析了工程中存在的泥沙问题,查明了泥沙的主要来源和时间段,河流的自我调节能力,获取了泥沙级配曲线等基础数据。根据水库淤积和冲淤的调控资料,总结了水库在汛期和非汛期的库容自我调控能力。在此基础上,针对泥沙问题、取水问题提出了针对性的工程措施,并作了专门的冲淤设计。     

鲁布革水电站水库放空冲沙及效果分析

鲁布革水电站水库库容小，入库泥沙含量大，泥沙淤积严重。为了延长水库使用寿命，充分发挥电站的经济效益，需每3～5年进行一次放空冲沙。1997年7月13～17日水库进行了放空冲沙，共冲出泥沙850万t，期间入库沙量350万t，基本达到了冲沙目的。冲沙效果推算和分析表明，如水库采用放空明流冲沙效果会更好，且不会造成不利影响。     

基于一维水沙模型的水库冲沙方式优化研究

在天然河流上修建水库,破坏了河流水沙原本相对平衡的状态。泥沙进入库区后发生落淤,从而导致水库淤积。在水库的实际运用中,冲沙措施被广泛用于减缓水库的淤积速率。然而,冲沙需要耗费水库较多的水量,影响了水库的综合效益,为此必须协调水库淤积与水库兴利效益之间的关系。在选定合理冲沙水位和冲沙流量范围的基础上,应用一维非均匀流不平衡输沙模型,结合某多沙水库现行调度规程,对多种拟定冲沙方案下该水库的冲沙过程进行长期模拟,计算各方案下水库多年平均淤积量和多年平均发电量等指标,据此选取合适的冲沙方案。结果表明,持续时间较长的低水位冲沙方式的冲沙效果相对较好,能够在一定程度上减缓水库的淤积速率,同时发电量的损失也相对较小。     

一元线性回归法径流预测在新疆克孜尔水库的应用

利用入库径流1986-2012年系列实测旬径流资料,根据一元线性回归方程原理,建立中长期预报方案,并对预报结果进行分析及精度评价。结果表明:该方法能满足中长期定量预报允许的许可误差,预报精度达到水文情报预报规范。     

上游梯级水库对设计洪水的影响分析

上游具有一定调蓄能力的水库建成后,将会对洪水产生一定程度的调蓄作用,文中考虑降雨的分布情况,并通过梯级洪水的计算,分析上游水库对索风营电站的设计洪水调节及削减洪峰的影响程度.     

Acute impacts of reservoir sediment flushing on fishes in the Yellow River

Dam sediment flushing can reduce reservoir sedimentation and deliver sediments to the downstream rivers. However, deceased fishes are often found in the Yellow River during the period of reservoir sediment flushing. To study the acute impacts of flushing and quantify threshold conditions for fish protection, field surveys and laboratory experiments were carried out during periods of sediment flushing. Field surveys in 2010 showed that dissolved oxygen (DO) decreased rapidly with the increase in suspended sediment concentration (SSC) and that deceased fishes involved 10 species. With the model of the severity of ill effects, the sediment flushing in 2010 was estimated to cause fish mortality of 0–20%. To study the lethal effect on fishes under controlled SSC conditions, laboratory experiments were performed with carp (Cyprinus carpio) exposed in water containing different SSCs. It is concluded that the high sediment concentration (average value of 90788 mg/l), fine particles (grain size < 0.075 mm), a long flushing duration (>2 days), and DO reduction (<2 mg/l) contribute to the deaths of fishes during the flushing period in 2010. To decrease lethal effects, the upper limits of SSC and duration are recommended as the peak SSC value of 55 000 mg/l and average value of 32 000 mg/l for the entire flushing period for flushing operations. The measures of SSC control and refuge construction are suggested for eco-friendly management.     

阎王鼻子水库产沙特性及排沙时机分析

阎王鼻子水库坐落在大凌河中上游,总库容为1.6亿m3,流域面积9 482 km2,属年调节大型水库。库址以上流域为半干旱丘陵区,植被较差。流域形状为扇形,坡度大,河道形状多属宽浅河槽,比降大,调节能力低,洪水形成的产汇流阶段的产沙、挟沙能力很强,洪水携带大量的泥沙入库。1流域产沙     

基于flushing time的春季水库优化调度可行性研究

针对三峡水库支流库湾春季水华问题,通过建立三维水动力模型,探讨了利用调峰调度和潮汐式调度促进干支流水体交换的可行性。研究表明,当4月水库实施调峰调度时,整个库湾水体的flushing time较常规调度有所缩短,尤其是库湾上游至中上游区域;当5月水库开始实施潮汐式调度时,水体体积较大的库湾下游区域的flushing time较常规调度方案有所缩短。可见,两种水库优化调度方案对增大干支流水体交换均具有可行性。当水库实施调峰调度和潮汐式调度联合调度时,整个库湾水体的平均flushing time较常规调度方案有不同程度的缩短,表明该联合调度方案更能促进干支流水体的交换。研究成果可为支流库湾水环境问题的防治提供借鉴。     

多泥沙水库排沙效应综合评价指标体系框架初探

世界上很多国家都采取人为排沙的方式缓解水库淤积,以延长水库寿命、增加水库库容。然而,受水资源短缺所限,水库排沙多注重排沙效率,忽视了高含沙水流下泄引起河床冲刷、溶解氧下降、含沙量剧增对下游河道内生境、生物生存的影响。本文立足国内外有关水库排沙对下游河道生态环境影响的研究成果,综合考虑排沙的经济、生态环境和社会影响,制定包括水库排沙效率及水库排沙对下游河道影响等内容的全方位评价指标体系,并以黄河小浪底水库调水调沙为案例,利用制定的指标体系全面评估了调水调沙对区域生态、经济和社会的综合效益,为今后准确地评估水库排沙的正负面效应提供支持。     

水库工程对1998年长江防洪作用分析

在抵御长江１９９８年的全流域性大洪水中，丹江口，隔河岩水库发挥了重要拦洪错峰作用，各支流水库也按接洪削峰进行了调度，通过总结各类不库对工江不同河段不同时期防洪的作用，说明干支流上各水库任务不同，即长江干流上的水库是直接负担干流防洪任务的，而支流上的水库，有的只负担本流域的防洪任务，有的兼顾或分担干流防洪任务，因此应充分考虑实时水雨情因素的影响，须在保证水库安全条件下，并精民调度中长江防洪发挥较大的     

Measurement and quantification of a sedimentation budget for a reservoir with regular flushing

This paper provides a case study of successful removal of reservoir sediment by empty flushing. The main aim of this study was to determine: (i) sediment inflow to the Cachí reservoir; (ii) the pattern and rate of deposition in the reservoir; (iii) the erosion within the reservoir during flushing; and (iv) sediment outflow at a downstream hydrological station during flushing. The results are integrated as a sediment budget for the reservoir. The drainage basin of the Cachí reservoir in Costa Rica is 785 km². The sediment budget for the period between two flushings indicates a sediment inflow to the reservoir of c. 930 000 tonnes and a net accumulation of c. 133 000 tonnes, or 14.3% of the sediment inflow. The sediment throughflow was also c. 133 000 tonnes up to the erosion phase of the flushing, and the outflow during flushing including bed load was 663 000 tonnes, i.e. 71.4% of the sediment inflow. Thus, the flushing of the reservoir was highly effective in releasing sediment. The balance of the sediment budget makes it probable that the major components of the sediment budget are of the right order of magnitude. The main principle to obtain correct sediment loads by the rating‐curve technique was to collect sediment data from a large number of storm events at equal time intervals during rising and falling stages. This was achieved by turbidimeter recordings. Because of the wide scatter of data, sediment rating curves were developed on mean sediment loads in discharge classes to avoid the bias of log regressions. The trap efficiency and sediment throughflow were determined with Sundborg's physically based sedimentation model. The throughflow amounted to 20% of the suspended sediment inflow, which compares well with the empirical budget. The depositional pattern in the Cachí reservoir was surveyed with side‐scan sonar, repeated echo‐soundings, and by excavating pits in deposits when the reservoir was empty. Deposition occurred mainly in the old river channel, indicating that the major part of the sediment is transported by density currents. The volume of eroded material in the reservoir during scour valve release was estimated by echo‐soundings before and after the flushing. Dry bulk density of the reservoir deposits was determined by X‐ray radiographic and densitometric analysis. The radiographic analyses indicated a dry bulk density of 0.4 g cm⁻³ of the loose material in the thalweg, and 0.7 g cm⁻³ of the whole deposition depth on the terraces. Copyright © 2000 John Wiley & Sons, Ltd.     

Driving factors of the flushing time of bays formed where tributaries enter a reservoir

Flushing time is an integrative parameter that can represent water exchange capacity and sensitivity to pollution threats. As bays formed where tributaries enter the Three Gorges Reservoir of China have experienced frequent algal blooms over the past decade, we examine the spatially variable flushing time of a typical tributary bay (Xiangxi Bay) by numerical tracer experiments. First, the tracer concentration reduction could be approximated well by a double exponential decay curve, and the local flushing time of Xiangxi Bay is determined using key flushing coefficients. Second, a sensitivity analysis is performed to examine the influence of upstream inflow, temperature difference, wind, water level of the reservoir, and daily water level fluctuation on the spatial variation in local flushing time. Finally, according to local flushing time values and the sensitivity analysis results, the bay can be generally characterized by three zones: riverine, transitional, and mainstream‐influenced zones. In particular, the local flushing times in the riverine zone are mainly affected by the upstream inflow. The difference in temperature between the reservoir mainstream and Xiangxi Bay is the main forcing in the transitional and mainstream‐influenced zones. This study is the first to investigate different driving factors for flushing time in a typical reservoir tributary bay. The findings provide insights on the transport processes in such water bodies, suggesting the possibility of using the longitudinal zonation of flushing time for reservoir management.