恰当使用水文资料 真实计算电站效益

通过对北方某些径流式小型水电站发电量与设计发电量差距较大原因分析,确定影响该经济指标的主要原因之一是设计中选用河道年径流资料不尽合理,从而提出了小水电设计中应从设计年倒推25～30年采用年径流水文资料的看法。表1个。     

应用“图表”计算径流式小型水电站动能指标的方法

径流式水电站由于无调节能力，水能计算的时段只能以日为单位，工作量大。应用流域内水文站实测水文资料的水能计算参数及图表，来计算本流域或自然地理条件相似的邻近流域各个径流式中小型水电站的动能经济指标，可避免一些不必要的重复劳动，大大节省计算工作量。经实际工程复算分析和运行资料验证，其成果接近实际，精度可达９０％以上，有一定实用价值。     

光照水电站坝址水文特性分析与设计洪水计算

光照水电站受上游梯级水库群和人类活动的影响,其水文特性较天然状况已发生改变。根据北盘江流域的水文、气象资料,在分析上游水工程调蓄影响的基础上,对工程区域的水文特性进行研究,并开展水电站设计洪水计算和分析。结果表明：北盘江流域降雨径流年内分配极不均匀,年降雨、年径流的80%以上集中在丰水期;本次复核的光照水电站洪水计算成果与可研阶段成果相比,差异不大,仍可采用可研阶段洪水计算成果。图5幅,表3个。     

小型径流式水电站水能复核研究

小型径流式水电站装机容量的确定,是通过对径流系列进行分析,对来流大小进行排频,并利用列表法计算电站不同装机容量对应的发电效益及年利用小时,引入经济指标,估算其投资效益比,选取适合小型水电站的合理装机。该方法可有效指导小型径流式水电站的装机复核,也可为类似工程提供一定的参考。     

怒江及澜沧江双雨季地区的小水电站径流分析计算

在“三江并流”区内的怒江和澜沧江中、上游区域中新建小水电站,由于缺乏水文资料,径流计算中通用的水文比拟法不适用于此区域。过去通常采用径流深查图法,经电站建成运行后验证此方法计算的径流成果偏小。分析后提出在怒江及澜沧江双雨季地区的小水电站可采用新的径流计算方法一即水量平衡法,并结合具体工程验证其合理性。     

流源水电站水文分析

通过祁门县流源水电站水文计算实例，介绍了小流域无资料地区水电站水文分析的一种方法，即通过降雨分析和径流分析，探索本地区水文要素之间的规律，寻求无资料地区与有资料地区（水文站）水文要素的联系。本文在整理了大量水文资料的基础上，采用水文比拟法，结合水文高坛拟法，结合水文高坛理论，推求流源水电站的多年平均雨量和多年径流系列。     

流域有众多小水电站的锦江水库降雨径流预报

根据降雨径流相关原理,结合锦江水库流域地理环境、水文、气象、上游小型水电站众多特点,将该流域划分为8个单元区,并在各单元区建立一个虚拟水库,代替众多小水电站调节水量的水库降雨径流预报模型,应用于锦江水库水文预报系统。2008年至今共6年的入库流量短期预报实践证明,该模型预报精度高,在水库防洪发电、水库调度应用中效果优良。     

黄河流域河川径流量的初多研究(上)

黄河干支流以往积累的径流资料,不能直接满足全流域各个小集水面积水文计算的需要。随着小型水利工程的大量开展,必需利用黄河干支流现有资料,加以综合分析和研究,寻求径流变化的规律,并用它来决定研究较少或尚未勘测过河流的径流特性和进行径流计算。我们这次的研究工作是在水文研究所结合水文分区工作进行的。共研究了多年平均径流量、年径流的     

英布鲁水电站水文特性及水文设计特点

英布鲁水电站水文特性、水文分析内容，与国内外其他水电站相比，特点明显。如：流域分旱、雨两季，降雨入渗强，径流年内年际均匀，洪水年内年际变幅不大。而电站为径流式，下游没有防洪要求。英布鲁水电站工程水文设计，充分考虑了这些特性。     

缺资料地区水电工程径流计算方法研究

针对缺资料地区水电工程水文计算难题,以国外两个水电站设计为例,在掌握全球共享气象、地形、植被、土壤基础数据的前提下,以基于3S技术的分布式水文模型SWAT为工具建模,利用Nash-Sutcliffe效率系数及相对误差指标评估径流模拟精度,论证分布式水文模型在缺资料地区水电站径流计算的可行性。     

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…