桓仁水电站汛限水位动态控制模糊推理决策模式与应用

以桓仁水电站2005年8月实际洪水过程为例,根据水库汛限水位动态模糊控制的概念,研究实时防洪调度中考虑综合信息后的汛限水位动态控制模糊推理决策模式,并与实际调度和常规调度过程进行比较,同时进行风险及效益分析。结果表明,在不增加水库及上下游防护对象风险的前提下,能抬高汛限水位,减少水库弃水,提高效益。     

碧流河水库汛限水位动态控制方法研究与应用

针对碧流河水库汛限水位控制运用中由于"静态控制"而导致洪水资源浪费的问题,从规划和实时运行两方面研究动态控制汛限水位的方法。首先研究了该水库汛限水位动态控制域的确定方法,在此基础上提出基于洪水预报和24小时降雨预报信息的实时动态控制方法,并以碧流河水库流域"2005.8.8"洪水实际调度为背景,介绍了水库水位的实时控制过程。结果表明,基于预报信息动态控制水库水位后,在没有额外增加防洪风险的前提下,提高了洪水资源的利用率。本文研究的方法具有较强的可操作性,可用于指导我国北方其他调节性好的水库的实时防洪调度。     

实时汛限水位动态控制方法研究

很多研究表明,汛限水位动态控制是协调水库调度中防洪和兴利间关系的有效方法,但大多集中于研究汛限水位控制域的确定,很少有文献针对汛限水位动态控制的核心—实时汛限水位动态控制进行研究。本文提出了一种实时汛限水位动态控制的方法,该方法首先利用24 h分类降雨预报作为判别指标,然后依据水文预报结果和水库的泄流能力计算控制水位、泄流量等具体指标。文中将该方法用于碧流河水库“19960810”场次洪水的调度中,结果表明,该方法能保证汛限水位动态控制的有效性,可以用做实时汛限水位动态控制的实施方法。     

基于降水预报信息的棉花滩水库汛限水位动态控制模型

为了提高汛期洪水资源的利用率,对棉花滩水库进行了汛限水位动态控制研究。从汛限水位动态控制条件、历次洪水预报误差等方面分析棉花滩水库实施动态控制的可行性。以2010年复核的汛限水位为基础,基于实时预蓄预泄方法,根据流域的短期降水预报信息、面临时刻水情信息、工情和灾情信息,结合洪水预报,确定适用于棉花滩水库的预蓄预泄调度模型,制定水库汛限水位实时动态控制方案,并进行相应的风险分析及效益计算。此方案在不降低原设计防洪标准的前提下,可增加水库蓄水量与发电效益。     

水库汛限水位实时动态控制模型研究

现行的汛限水位方法一般未能考虑预报信息，因而严重制约了水库汛期兴利效益的发挥。通过对实时调度中的可接受风险的研究，在调度期内控制防洪风险在可接受水平内；讨论实时调度与传统汛限水位之间的关系．由调度末水位耦合汛限水位，由此建立了带有机遇约束的水库汛限水位实时动态控制模型。结合三峡水库围堰发电期的汛期调度，进行了实例研究，结果表明，在不同的预报来水以及预报精度情况下，水库汛限水位实时动态控制模型能在不降低防洪标准的前提下，显著提高水库的兴利效益。     

碧流河水库汛限水位动态控制方法应用

分析了碧流河水库传统的汛限水位控制及其调度方式即“静态控制法”存在的一些不足。提出了以产流预报的累计净雨量作为判断指标的防洪预报调度方式,并以2011年8月8日迎战9号台风“梅花”为例,介绍了碧流河水库采用汛限水位动态控制方法进行洪水调度的过程,通过风险分析和效益分析,得出汛限水位动态控制方法,在保证水库及上下游防洪安全的前提下,充分利用洪水资源,实现了从抵御洪水向管理洪水转变,对我国水资源严重短缺的北方地区具有重要的理论意义和参考价值。     

漳泽水库汛限水位动态控制必要性及可行性分析

随着当地社会经济的快速发展,漳泽水库蓄水兴利与防洪安全的矛盾越来越突出。根据水库实际情况,合理确定水库汛限水位,研究汛限水位动态控制方法,建立切实可行的水库汛限水位控制模式,为更好地利用汛期洪水资源来提高水库兴利效益,在现有基础上对漳泽水库汛限水位动态控制进行了合理性分析。     

故县水库主汛期汛限水位动态控制方案研究

分析了故县水库主汛期入库洪水特点,对其主汛期汛限水位动态控制防洪调度判别条件、动态控制方式进行了研究,通过对动态控制运用后的防洪风险进行分析,认为对5年一遇以下洪水进行汛限水位动态控制运用的风险较小,并依此制定了故县水库主汛期汛限水位动态控制运用方案。     

洪水预报误差对预泄控制法汛限水位动态控制的风险分析

以清江大龙潭水库为例,利用误差及统计学理论,进行洪水预报误差对预泄控制法汛限水位动态控制的防洪调度风险分析,结果表明,利用洪水预报进行大龙潭水库汛限水位动态控制存在一定的防洪调度风险,但风险较小,可通过提高预报精度、结合气象预报信息决策调度,实现风险可控。     

鲁布革水库汛限水位分期动态控制风险及效益分析

新的防洪法规定“在汛期,水库不得擅自在汛期限制水位以上蓄水,其汛期限制水位以上的防洪库容的运用,必须服从防汛指挥机构的调度指挥和监督”。由于各流域(电站)汛期开始、结束时间每年变化很大,汛期来水分布不均匀,水库在固定汛限水位下运行,水库的调节能力得不到充分发挥,因此,如何结合工程实际有效进行汛限水位分期动态控制,是许多水电厂急需解决的热点问题。鲁布革水库汛限水位实行了分期动态控制方式,对其实施动态控制的风险及效益进行了分析。     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。     

Fish assemblage response to recent mitigation of a channelized warmwater stream

Various designs of low‐head dams are used to rehabilitate streams or forestall upstream channel incision after channelization. We report on the efficacy of using notched sills and grade control structures (GCS) to restore the fish assemblage in Luxapallila Creek, Mississippi. We tested the null hypotheses that habitat variables and species richness, evenness, and assemblage structure would not differ among: (1) a channelized segment with no modifications; (2) a channelized segment mitigated by the installation of sills and GCS; (3) a segment upstream of the installations and undergoing channel incision; and (4) an unaltered segment. Although habitat variables changed, neither species richness, evenness, nor fish assemblage structure differed between mitigated and channelized segments with both exhibiting less richness and different assemblage structures than the unaltered segment. Lack of differences in species richness between the incised and unaltered segments suggest that the GCS may have halted the negative effects of upstream channel incision before species were extirpated. Conspicuous habitat differences between the altered (channelized and mitigated) and unaltered segments were lack of backwaters and canopy coverage and finer substrates in the altered segments. Our results suggest a more comprehensive rehabilitation strategy is required in Luxapallila Creek. Published in 2003 by John Wiley & Sons, Ltd.     

NUMERICAL STUDY OF WAVE EFFECTS ON SURFACE WIND STRESS AND SURFACE MIXING LENGTH BY THREE-DIMENSIONAL CIRCULATION MODELING

1. INTRODUCTION Coastal and continental shelf regions are characterized by intensive interaction between wave and current. These regions are of great economic significance to mankind. Therefore, the modeling of wave and current as well as their mutual int…