碧流河水库后汛期汛限水位及控制运用方式

水库汛期分期后上下游防洪标准的确定是水库分期运用的难点,针对北方地区后汛期来水特点,提出从防洪、兴利与两者权衡3个角度通过优化推求汛限水位备选方案,并协调方案中各指标间的复杂关系,建立汛限水位多方案分层模糊优化决策模型。经应用于碧流河水库表明,该方法在不改变水库原防洪标准的前提下,抬高水库后汛期汛限水位。研究结果为决策提供了技术支持,对北方缺水地区的其它水库有指导意义。     

三峡水库动态汛限水位洪水调度风险指标及综合评价模型研究

汛限水位是综合利用水库运行和调度的重要参数之一,也是协调防洪和兴利矛盾的焦点所在。现行的汛限水位过多地考虑了小概率洪水事件,不能充分挖掘水库汛期的兴利效益,因此,采用动态汛限水位进行调度,对综合利用水库的运行具有重要的理论意义和实用价值。根据三峡水库围堰发电期的调度规程,建立预报预泄调度模型,采用宜昌站1882-2001年汛期实测日流量资料,实现了考虑预报信息的动态汛限水位洪水调度模拟;提出了多目标风险指标体系;计算了9种动态汛限水位方案下的风险指标值,通过综合评价模型对各方案进行比较和优选,得到了相对合理的动态汛限水位方案。     

广西澄碧河水库汛期洪水分期及其汛限水位浮动控制运用研究

本文根据水库洪水分期方法和汛限水位浮动控制理论对广西澄碧河水库进行洪水分期和汛限水位浮动控制研究，结果在不降低大坝防洪标准前提下对水库防洪调度方案进行优化，即水库汛期4～8月份以原汛限水位迎洪．9月份开始可在1．80m范围内上浮汛限水位。最后，对采用该方法可能存在的风险因素与风险程度进行探讨。     

基于预报及库容补偿的水库汛限水位动态控制研究

结合清江流域梯级水电站工程特性及防洪任务,以不降低梯级防洪标准为原则,建立基于预报及上游水布垭水库库容补偿的汛限水位动态控制模型,推求隔河岩水库汛期汛限水位动态控制方案。计算表明,该模型在不降低水库及梯级原有的防洪标准前提下,能有效利用上游水布垭水库的防洪库容,分担隔河岩水库部分防洪任务,并显著提高其发电量。其中,多年平均弃水量减少4．1444亿m~3,发电量增加1．2172亿kW·h。     

动态汛限水位研究及在沭河青峰岭水库的应用

动态汛限水位控制是指水库在汛期,根据实时雨、水、墒情,利用暴雨、洪水预报成果,在不降低水库防洪标准,确保水库、上下游地区防洪安全的前提下,按照水库动态汛限水位控制方案确定的控制范围对汛限水位进行浮动的调度过程.结合防汛指挥系统建设,采取动态汛限水位,在保证安全的前提下尽可能多蓄水充分利用雨洪资源、发挥防洪与兴利的最佳结合效益.     

岳城水库汛期洪水资源化分析研究

在对岳城水库的常规防洪调度方案进行分析的基础上,研究了水库进行防洪预报调度的可行性,利用模糊集分析法计算了水库汛期经验隶属度值,对汛限水位进行了动态分析计算,拟定了基于防洪预报调度的洪水调度优化方案,利用防洪预报和常规水位双重约束条件,规避了由于防洪预报误差带来的风险.经过计算与分析,岳城水库防洪预报调度优化方案不但可以在一定程度上提高防洪标准,而且随汛限水位的提高,有效增加了兴利库容.     

金沙江下游梯级水库运行期设计洪水及汛控水位

研究探讨梯级水库运行期设计洪水计算理论和方法,实现防洪和发电效益最大化。采用t-Copula函数建立各分区洪水的联合分布,通过蒙特卡罗法和遗传算法(GA)推求金沙江下游梯级水库的最可能地区组成;分析计算各水库运行期的设计洪水及汛控水位。结果表明:①最可能地区组成结果合理可靠,可为梯级水库运行期设计洪水的分析计算提供依据;②金沙江下游梯级水库受上游水库调蓄影响显著,向家坝水库1000年一遇设计洪峰15400m^3/s(35%),3d、7d和30d洪量的削减量(削减率)分别为35.6亿m^3(33%)、70.2亿m^3(30%)和85.0亿m^3(11%);③在不降低防洪标准的前提下,下游各水库在运行期汛控水位相比汛限水位可适当抬高,白鹤滩、溪洛渡和向家坝水库的汛控水位(汛限水位)分别为788.82m(785m)、570.67m(560m)和371.36m(370m),汛期年均发电量分别增加2.1%、6.1%和1.4%,年增发电量17.1亿kW·h。     

三峡水库汛期控制水位及运用条件

随着长江上游梯级水库的陆续建成投运，三峡水库的水文情势和功能需求与设计条件相比发生了显著变化，仍维持固定的汛限水位运行已不能适应新形势需求。本文通过辨析三峡水库设计阶段汛限水位的设置条件，挖掘流域洪水特性和洪水遭遇规律，论证三峡水库汛期运行水位动态控制的可行性。结果表明:①三峡水库设计推求的汛限水位145 m的适用条件是应对流域性大洪水，而流域性洪水发生概率小且特征明显，可以通过水文水情分析提前预判。②根据流域洪水类型、洪水分期和遭遇规律，预判发生区域性大洪水时，三峡水库6月初至梅雨期结束汛限水位按145 m设置，从梅雨期结束后逐渐提高水位，8月20日后过渡到155 m。③在考虑上游水库群联合调度和气象水文预报的配合下，正常年份三峡水库汛期运行水位可在155 m上下浮动，并考虑提前蓄水。④三峡水库汛期运行水位动态控制，不会增加防洪风险和库区淤积风险，对中下游江湖关系和水文情势有利，可显著提高发电、航运、生态保护和供水等综合利用效益。     

三峡水库汛期控制水位及运用条件

随着长江上游梯级水库的陆续建成投运，三峡水库的水文情势和功能需求与设计条件相比发生了显著变化，仍维持固定的汛限水位运行已不能适应新形势需求。本文通过辨析三峡水库设计阶段汛限水位的设置条件，挖掘流域洪水特性和洪水遭遇规律，论证三峡水库汛期运行水位动态控制的可行性。结果表明：① 三峡水库设计推求的汛限水位145 m的适用条件是应对流域性大洪水，而流域性洪水发生概率小且特征明显，可以通过水文水情分析提前预判。② 根据流域洪水类型、洪水分期和遭遇规律，预判发生区域性大洪水时，三峡水库6月初至梅雨期结束汛限水位按145 m设置，从梅雨期结束后逐渐提高水位，8月20日后过渡到155 m。③ 在考虑上游水库群联合调度和气象水文预报的配合下，正常年份三峡水库汛期运行水位可在155 m上下浮动，并考虑提前蓄水。④ 三峡水库汛期运行水位动态控制，不会增加防洪风险和库区淤积风险，对中下游江湖关系和水文情势有利，可显著提高发电、航运、生态保护和供水等综合利用效益。     

基于风险分析确定水库汛限水位动态控制约束域研究

基于预报预泄原理推求水库汛限水位动态控制约束域,确定上限的依据是在洪水来临前将水位降低至固定(或者分期)汛限水位以下,确定下限的依据是在洪水退水阶段将水位回充至固定(或者分期)汛限水位以上.为充分考虑来水起涨、退水过程的不确定性,采用实测资料进行起涨阶段预泄和退水阶段回充调度,分别推求预泄末和回充末水位的经验频率分布,由此可建立风险分析模型,从理论上解决水库防洪标准不降低和退水阶段能回充等问题.以三峡水库正常运行期为背景,推求了主汛期汛限水位动态控制约束域的上、下限值,结果表明:即使不考虑水文预报误差,基于风险分析的动态控制域上限较采用预泄能力约束法上限低、下限高,提出的方法完善了基于预报预泄原理确定水库汛限水位动态控制域的理论.     

Adaptive reservoir flood limited water level for a changing environment

As streamflow is non-stationary due to climate change and human activities, adapting reservoir operation in the changing environment is of significant importance. Specifically, the flood limited water level (FLWL) needs to be re-established to ensure flood safety when the reservoir inflow is altered. The aims of this study are: (1) to clarify the relationship between the FLWL and streamflow when statistical parameters of the flood peak and volume vary through time and (2) to re-establish the FLWL when the reservoir inflow changes under the non-stationary condition. The adaptive FLWL is derived based on flood routing of non-stationary design floods, and the flood risk probability is then estimated. With China’s Three Gorges Reservoir (TGR) as a case study, the changing pattern of FLWL is quantified when statistical parameters (i.e., mean, \( C_{\text{V}} \) and \( C_{\text{S}} \)) of design floods have a linear temporal trend. The results indicate that the FLWL is sensitive with design floods, i.e., (1) means of design flood peak, 3-day volume, 7-day volume, 15-day volume and 30-day volume yearly decrease by 33 m³/s, 0.008, 0.021, 0.482 and 0.905 billion m³, respectively, (2) when the non-stationary design flood is used, the cumulative flood risk probability of the reservoir water level exceeding 175.0 m during 2011–2030 decreases from 1.98 to 1.82% with the conventional FLWL scheme and (3) the FLWL of the TGR could be re-set without increasing the flood risk probability, and the FLWL would increase about 4.7 m by 2030 in this non-stationary streamflow scenario. These findings are helpful to derive the FLWL in a changing environment.     

考虑综合利用要求的三峡水库提前蓄水方案

采用三峡水库汛期分期方案,将蓄水时间提前至汛末期,综合考虑上下游防洪、发电、通航和蓄满率等要求,建立了多目标蓄水调度模型,构建了"优化-模拟-检验"的算法流程,采用遗传算法进行求解。结果表明,最优方案在满足上下游防洪安全要求的前提下,蓄水期可增发电量17%,减少弃水44%,蓄满率和通航保证率显著提高。通过对汛末期防洪库容进行科学划分和对蓄水调度图进行优化,既确保防洪安全又最大限度挖掘兴利效益,为研究水库汛末蓄水调度问题提供了一种新的思路和方法。     

基于多目标遗传算法的巨型水库群发电优化调度

低碳时代,水电作为清洁可再生能源,节能发电调度为梯级水电联合调度运行带来了难得的历史机遇,如何有效地开展梯级水库群优化调度,充分合理利用水能资源,是流域梯级电站管理迫切需要解决的问题。文章在对清江梯级与三峡梯级径流特征分析的基础上,建立了以水库群整体发电量最大和弃能最小为目标的梯级调度模型。根据电力系统对三峡、葛洲坝、水布垭、隔河岩、高坝洲水电站的要求,用1951—2002年的月径流资料和典型年的日径流资料进行长期和短期优化调度,采用多目标遗传算法得到清江3个电站、三峡-葛洲坝2电站单独运行和联合优化调度发电指标,5库联合优化调度系统多年平均发电量增加约21亿kW.h;短期(日)优化调度较长期(月时间尺度)优化调度发电效益有进一步提升,增发电量约9.68亿kW.h。研究表明,充分利用清江和三峡梯级实际运行位置相近、水力联系紧密、互补性强的特点,统一安排电站机组运行模式,合理分配机组出力,可在来水量相同的条件下获得更大的效益。     

A method for implementing the real-time dynamic control of flood-limited water level

Many studies have proven that the dynamic control of flood-limited water level (DC-FLWL) is an effective methodology to balance flood control and water conservation for reservoir operations during the flood season. However, these studies have focused on determining the bound of FLWL; few studies have investigated the implementation of real-time DC-FLWL, which actually is the core of DC-FLWL. To implement real-time DC-FLWL, a new method for considering rain forecast is presented in the present study. The proposed method includes two procedures: prerelease and prefill, which constitute the prerelease–refill and the prefill–prerelease schemes. For each scheme, the categorical rain forecast with a lead time of 24 h is used as the trigger for different actions, while hydrological forecast and discharge are used to calculate the action details, including the water level reserved and the amount of discharge water. The method is examined via the operation of the flood event “19960810,” which occurred in the catchment of the Biliuhe reservoir in China. The results show that although the maximum water level and the maximum discharge of the three schemes have the same value, the water level at the end of both the prerelease–refill and the prefill–prerelease schemes of DC-FLWL is 68.8 and 68.5 m, which are both higher than the planning scheme, i.e., 68.1 m. These findings further confirm the effectiveness of DC-FLWL and also prove that the proposed method is suitable for implementing real-time DC-FLWL.     

洪水资源利用风险适度性分析

洪水资源利用有助于缓解北方地区的水资源紧缺形势,风险适度性作为洪水资源利用三大适度性之一,用于指导洪水资源的合理开发与安全利用。在水库汛限水位调整中,提出采用不同频率设计洪水进行不同汛限水位条件下的洪水调节计算,并结合水库的经济与生态供水目标进行长系列用水调度模拟和供水效益分析,综合确定风险适度性的方法。对密云水库的计算分析表明,主汛期汛限水位从原设计的147.00 m安全抬高至目前的152.00 m是可靠的,其风险阈值上限为153.20 m;后汛期汛限水位可从目前的154.00 m安全抬高至155.40 m。两种情况下水库供水保证率可以分别提高0.30%和0.01%,且大坝和下游防护区的防洪风险率分别为0.01%和1%,与原设计一致,满足洪水资源安全利用的风险适度性要求。     

Impact assessment of Three Gorges Dam’s impoundment on river dynamics in the north branch of Yangtze River estuary,China

As one of the world’s largest hydropower projects, the Three Gorges Dam (TGD)’s 156–175 m height storing test in flood recession seasons during 2006–2011 has aroused international attention. The novel approaches of cross-wavelet transform and wavelet coherence were firstly introduced to reveal the significant coherence and time lag property in time–frequency space between river dynamics in hydrological stations along Yangtze River. Then, using the optimum lag time nodes, corresponding regression models between river dynamics in these stations were established and utilized to assess the river dynamics in stations downstream under the impact of TGD’s impoundment. Results showed that the average decrease ratio of 24.3 % in the Three-Gorge reservoir outflow was caused in TGD’s impounding periods during 2006–2011. The corresponding average decrease ratios of 25.1, 16.5 and 1.9 % in Yichang flow, Datong flow (with 6 days lag), and estuarine Santiao river stage (with 32 days lag), respectively, were caused by TGD’s impoundment during 2006–2011. In addition, the impact weights of multiple driving factors on estuarine river dynamics were discussed, and the main factor of the combined impacts of estuarine tidal fluctuation and sea level change while the secondary factor of the upper stream inflow were demonstrated. A further suggestion about the optimization design of TGD’s safety impounding scheme was proposed to prevent estuarine saline water intrusion by guaranteeing the average daily increase of Three Gorges reservoir water level lower than 1.11 m/day during TGD’s impounding period.     

基于防洪库容总量控制的雅砻江下游梯级水库蓄水策略研究

根据长江防御洪水方案对雅砻江梯级水库的防洪库容预留要求,分析了预留防洪库容对梯级电站蓄水发电的影响。结合雅砻江水电开发的特点,提出了梯级水库防洪库容总量控制的解决思路,建立了基于防洪库容总量控制的蓄水期发电量最大模型,计算分析了9种不同来水情景的梯级水库优化蓄水方案,并给出了梯级水库总体优化蓄水策略。对该类问题研究具有一定借鉴意义。     

Floodwater utilization for cascade reservoirs based on dynamic control of seasonal flood control limit levels

Reservoirs play an important role in flood control and conservation, in which the flood control limit level (FCLL) is the most significant parameter of the tradeoff between flood control and comprehensive utilization of water resources. This study was aimed at constraining the seasonal FCLL for cascade reservoirs to obtain more economic benefits without reducing the original flood prevention standards. Based on flood initiation and ending times during the flood season, fuzzy set theory was used to build the experiential and theoretical membership function of each day, which clarified the relationship between the seasonal FCLL and the designed FCLL, and then the total flood season was divided into sub-seasons. The seasonal FCLL was revised by analyzing numerous flood control operation schemes of cascade reservoirs to satisfy a given flood prevention standard. Using the case study of ShiQuqn and XiHe cascade reservoirs in the Hanjiang River, the proposed method was demonstrated to provide an effective design for the seasonal FCLL, which increased the FCLL in the pre-flood and post-flood seasons. Forty-five operation schemes with different combinations of ShiQuqn and XiHe reservoir’s FCLLs under five flooding frequency scenarios were evaluated to revise the seasonal FCLL. An optimization model with real-coded genetic algorithm was proposed to maximize hydropower generation by dynamic control of the FCLL. The results show that compared with the traditional operation, joint operation based on dynamic control of FCLL can generate 0.23 × 108 kWh (3.18%) more hydropower for the cascade reservoir system during the flood season without increasing the flood risk.     

优化的NSGA-Ⅱ方法在马莲河流域水资源综合管理中的应用研究

根据马莲河流域水资源总量极端贫乏、年际年内分配不均、常规水资源量低、水污染问题较严重等特点,利用系统分析理论和优化技术建立了流域的大系统、多目标水资源优化配置模型,并利用优化的NSGA-Ⅱ方法进行求解,得到流域2020年期望水资源配置下的最佳分配方案为:流域总供水量57 086×104m3,工业供水量21 690×104m3(总产值约为144.6亿元),能源基地供水量4 329×104m3(总产值约为346.32万元),农业供水量20 840×104m3,生活供水量9 452×104m3,生态供水量811×104m3。对比期望方案供水量增加了6 710×104m3,综合缺水率减少了11.41%。并根据预测的流域的分配方案和预测的流域需水量,进行了流域的水资源平衡分析,通过平衡分析的结果进行流域的综合管理研究。2020年在最优水资源分配方案下,工业缺水率3.21%、减少了4.51%;能源基地缺水率0.00%;农业缺水率4.64%、缺水率增加26.17%;生活缺水率0.00%;生态缺水率1.00%、缺水率增加了1.00%。配置方案实现了流域内水资源的最佳分配,使宝贵、有限的水资源产生最大的社会、经济及环境效益,为流域经济、能源产业的快速发展提供水资源保障。