锦屏一级水电站第四阶段工程蓄水方案优化

在分析锦屏一级水电站第四阶段工程蓄水设计方案的基础上,提出了新的蓄水方案优化思路,建立了该工程蓄水期梯级电站发电量最大模型,并采用POA法进行求解。对雅砻江近10 a实际来水过程进行了优化调度计算,基于分析成果,提出了工程蓄水优化方案。采用2014年汛期实际来水进行设计方案和优化方案对比分析,结果表明,两方案均能满足工程蓄水要求,其中,优化方案发电用水量增加约9.5亿m3,下游梯级电站发电量增加约8.6亿kW·h。     

Looking to the past to ensure the future of the world's oldest living vertebrate: Isotopic evidence for multi‐decadal shifts in trophic ecology of the Australian lungfish

Meeting the conservation challenges of long‐lived animal species necessitate long‐term assessments of trophic ecology. The use of dietary proxies, such as ratios of naturally occurring stable isotopes in animal tissues demonstrating progressive growth, has shown considerable promise to reconstruct trophic histories of long‐lived organisms experiencing environmental change. Here, we combine innovative radiocarbon scale‐ageing techniques with stable isotope analysis of carbon and nitrogen from cross sections of scale to reconstruct the trophic ecology of Australian lungfish (Neoceratodus forsteri) across its remaining global distribution. Over a 65‐year period, we found pronounced temporal shifts in the δ¹³C and δ¹⁵N isotopic ratios of lungfish that coincided with a period of hydrological modification by dams and land‐use intensification associated with agriculture and livestock grazing. In the Brisbane and Burnett Rivers, whose hydrology is substantially regulated by large dams, lungfish showed consistent trends of δ¹³C depletion and δ¹⁵N enrichment over time. This may indicate anthropogenic changes in background isotopic levels of basal energy sources and/or that additional seston exported downstream from impoundments represent a carbon source that was previously unavailable, thus shifting lungfish diet from benthic‐dominated primary production typical of unmodified river systems, to pelagic carbon sources. By contrast, δ¹³C ratios of lungfish in the unregulated Mary River were more stable through time, whereas δ¹⁵N ratios increased during a period of dairy industry expansion and increased application of nitrogen fertilization and then subsequently decreased at the same time that rates of pasture development declined and nutrient inputs presumably decreased. In conclusion, we provide evidence for human‐caused alterations in background isotopic levels and potential changes in availability of benthic versus pelagic energy resources supporting Australian lungfish and demonstrate how detectable trophic signals in long‐lived fish scales can reveal long‐term anthropogenic changes in riverine ecosystems.     

三峡水库蓄水后上下游河段水沙特性变化及影响因素分析

泥沙淤积问题是三峡工程的关键技术问题之一,关系着长江水资源的开发利用、生态环境保护、经济发展。基于2002-2016年期间,三峡水库上、下游设置的11所重要控制性水文站水文泥沙监测资料,深入系统地探讨水文泥沙参量的变化特征,进一步分析水文泥沙参量的相关性和三峡水库的冲淤特性,探究了泥沙特性变化的原因。研究结果表明:三峡水库自施工期蓄水、初期蓄水、试验性蓄水的整个过程,对三峡水库上下游河道的水沙特性影响较大。越靠近三峡大坝的河段,受三峡水库的影响越大;三峡水库抬高水位,导致上游大部分河道流速变小,河道过水断面和水动力条件发生改变,导致入库泥沙越来越少,越来越细;三峡水库上游长江干流和支流上修建的梯级电站拦蓄了大量的泥沙,年输沙量、年均含沙量、中值粒径、年输沙模数都显著降低。年径流量和输沙量、年均含沙量、年输沙模数在2004-2013年间具有较好的相关性,曲线变化规律类似,2013年后受三峡水库蓄水的影响,出现弱相关;年径流量能表征泥沙参量的变化特性;年输沙量和年均含沙量在2002-2016年间皆具有较好的相关性。2007年前三峡水库淤积量呈增长趋势,其后三峡水库泥沙淤积量逐渐降低。在水库冲淤和泥沙特性方面,汛期三峡水库水位对其影响较大;枯水期的高水位对其影响并不大。研究成果将为长江流域梯级电站和航道的规划设计、三峡水库的运行管理提供理论支撑。     

2016年秋长江中下游枯水分析及对水库调度的启示

2016年7月长江中下游发生了区域性大洪水,上中游水库群联合调度,发挥了重要的防洪作用。洪水过后涝旱急转,长江中下游干流及“两湖”（洞庭湖、鄱阳湖）水位持续走低,9月份出现了历史同期严重枯水。为了探究此次枯水成因,总结经验规律,采用水量平衡法和水位流量关系曲线方法还原了2016年秋季枯水过程。对比分析发现,天然来水偏少和水库群拦蓄是导致长江中下游干流及两湖水位严重偏低的主要原因。此外,针对2020水平年投入运行的水库群规模将进一步扩大,汛末水库群蓄水对长江中下游来水的影响可能将持续加大且呈现常态化的现象,指出加强中长期水文预报技术与水库群联合蓄水研究是下一步的重点研究方向。     

高拱坝分期施工和分期蓄水仿真计算软件研制

根据《混凝土拱坝设计规范》中分析分期施工、分期蓄水施工程序及蓄水过程对坝体应力影响的要求,开发了一套基于有限单元法的分期施工、分期蓄水仿真分析计算软件。在输入必要的控制参数后,软件可自动完成计算网格生成、有限元计算、计算成果处理及图形和表格输出等,提高了计算效率和计算质量,为设计人员提供了一个实用的计算分析平台。     

THE ROLE OF STREAMS OF DIFFERENT SIZES IN RECOVERY OF FISH FAUNA IN THE PILICA RIVER CATCHMENT

Fish and lampreys were sampled by electrofishing in the Pilica River tributaries (the Vistula catchment, Poland) in 1992–1994 and 2003–2005. The patterns in fish assemblages were recognized on the basis of fish biomass using Kohonen's self‐organizing map (SOM) technique, combined with the indicator values (IndVal) for assessment of associations of fish species with particular SOM regions (and respective environmental conditions). Although the fish samples were clustered mostly according to the stream features (size, regulation, and pollution), a weaker temporal gradient indicated a recovery of the ichthyofauna in some smaller streams. The larger tributaries served as sources of colonisers for both the Pilica and the smaller streams. The differences between SOM subclusters in the quality of the aquatic environment were effectively presented with certain biological measures, including the dominances of potentially large species and non‐psammophilous rheophils, which are proposed as good bioindicators. It is worth mentioning that some closely related species (ide and dace, silver bream and bream, golden loach and spined loach, and Ukrainian lamprey and brook lamprey) were significantly associated with different SOM regions (and respective environmental conditions), perhaps in this way avoiding competition. Copyright © 2013 John Wiley & Sons, Ltd.     

初次蓄水对瀑布沟库首拉裂体影响的监测分析

施工期监测成果表明,瀑布沟电站库首右岸拉裂变形体支护结构荷载变化正常,坡体位移较小,蓄水前处于稳定状态。初次蓄水对瀑布沟库首右岸拉裂体产生了一定程度的影响。依据蓄水期间拉裂体宏观变形现象和监测资料,运用比较法、作图法和特征值统计法等对拉裂体支护结构荷载变化和变形进行分析。在此基础上综合分析后认为：受蓄水影响较大的是强卸荷底界限以上的岩体,坡体主要的变形方式为浅表松动带蠕滑变形;坡体位移随高程增加而增加,地表累计合位移 10 ～ 20 mm ,最大平均位移速率为 0.10mm/d ;蓄水使水位高程以下的锚索荷载产生了明显的减小,最大减小量 70.0 kN 。从初次蓄水后连续的监测成果分析,瀑布沟库首右岸拉裂体目前仍处于整体稳定阶段。     

三峡库区156 m蓄水水文泥沙变化分析

为掌握三峡水库2007年156 m蓄水过程中库区水文河道变化情况,通过观测与分析三峡库区蓄水过程的水沙变化,探讨蓄水过程水位、河道比降及水文泥沙运动的变化规律,为三峡库区175 m蓄水后的水面线对比分析、回水区的界定等研究打下基础,同时也为三峡库区175 m正常蓄水运用后,三峡水库库尾重庆变动回水区河段的水沙冲淤变化、河道走沙规律分析研究提供了条件。     

三峡及金沙江下游梯级水库群蓄水期联合调度策略

针对三峡及金沙江下游梯级水库群汛后竞争性蓄水矛盾,以溪洛渡、向家坝、三峡、葛洲坝梯级四库系统为研究对象,采用不同来水年型、蓄水时间和起调水位构建蓄水情景集;以蓄水期期望发电量最大为目标,建立蓄水期多目标联合随机优化调度模型,生成各蓄水情景下的最优蓄水方案;基于蓄满率、梯级期望弃水量、梯级平均期望出力对各方案进行评价,推荐丰水年溪洛渡、向家坝9月11日起蓄、三峡9月10日起蓄,平水年溪洛渡、向家坝9月11日起蓄、三峡9月1日起蓄,枯水年溪洛渡、向家坝9月1日起蓄、三峡8月21日起蓄。     

对长江三峡工程库区3期蓄水库底清理工作的思考及建议

3期清库是确保三峡库区3期蓄水按时完成和三峡水资源环境安全的重要措施.3期清库目前面临如下主要问题：剩余移民搬迁难度大,库底清理任务艰巨;3期清库经费紧缺,计划尚未下达,库区清库工作受到一定影响;清库规范及标准需要修订、完善并尽快出台,以便指导和规范3期清库工作;影响3期清库工作的其他问题.建议：要高度重视,加强领导,切实搞好3期清库工作;3期清库工作要早计划早准备早部署;要尽快修订、出台3期清库规范及标准;要尽早下达3期清库通知,并分类合理安排清库时间;要适时研究和加强库区水库综合管理工作;及时研究解决影响3期清库的“瓶颈”问题.