潇湘水库入库径流随机模拟

针对潇湘水库的实测入库径流资料，采用了数学模型与模拟模型相结合的随机动态规划模拟模型，对萧湘水库的年径流的模拟采用了一阶自回归模型，对于月径流的模拟，则采用了相关解集模型来模拟，通过对水库入库径流的模拟，得到水库的入库径流过程。     

水库群供水或灌溉径流补偿调节方法改进

为改进水库群供水或灌溉径流补偿调节方法,提出以水库群内各水库均衡供水、总弃水量最小为原则的改进思路,把常规的各水库之间确定型补偿改为各水库分时段动态补偿,以水库群各水库弃水之和最小为目标,以各水库实时空闲库容系数作为判断条件,确定各水库蓄放水次序并分配计算放水量。使用时历法长系列连续计算,统一常用的水库群径流补偿调节模式,结果可以获得比原有常规方法更合理的供水或灌溉过程和水库综合效益。     

长则水库可供水量计算

由于长则水库流域内没有水文监测资料，此次径流计算采用《山西省水文计算手册》，计算供水保证率为50%时，入库径流月分配成果，并将其作为水库月来水量。再根据水库实际用水情况、水库特征值等，运用列表法年调节计算设计保证率为50%时长则水库最大可供水量。     

江河水资源分配模型

对现有水资源模型大都团结局部地区的不同水源和用户进行研究，由于没有考虑河流区间的径流汇入和河流的连续性以及对水库的水量调配，因此，难于适合江河水资源分配情况，江河水资源分配模型是将水库最优放水流量以及下河段的区间入流按用户或河段进行分配，以使全河获得最大分配模型是将水库最优放水流量以及下游河段的区间入流按用户或河段进行分配，以使全河获得最大效益，在此前提下的两种模型－优化模型理论上科学合理，但不适     

甘棠江水电站水能计算探讨

甘棠江水电站上游有青狮潭水库,流域区间无径流资料,电站水能计算比较复杂。用分区综合计算方法来计算其径流,并介绍资料短缺地区径流计算方法,分析灌溉水量计算方法,径流式电站电能计算方法。表1个。     

龙羊峡水库径流调节作用及效益分析

为了分析龙羊峡水库自投运以来的径流调节作用和综合效益,通过对龙羊峡水库投运前后黄河上游水库运行方式的变化以及水库在年内、年际间水量调节的阐述,讨论了龙羊峡水库的径流调节作用,分析了龙羊峡水库因径流调节抬升下游电站发电水头和减少弃水量所带来的发电效益,通过拦蓄洪水、削减洪峰所带来的防洪效益,通过龙羊峡、刘家峡两库联合运用带来的灌溉、防凌效益,以及由龙羊峡水库调节而减少的下游在建电站工程导(截)流成本、提高梯级电站调峰能力等方面的效益。     

宿鸭湖水库年径流特征及丰枯划分初探

宿鸭湖水库位于汝河中游,是以防洪为主,兼有灌溉、养殖、发电等多种功能的大型平原水库。因此,研究宿鸭湖水库年径流特征及丰、枯划分方法,对预估未来水文情势和水量科学调度及水资源合理利用具有十分重要的意义。     

雅鲁藏布江中游径流还原计算方法探析

随着西藏"一江两河"地区人类活动的不断增加,水文断面所测的径流资料,在数量和时程分配上已不能代表河流的天然状况,在利用这些资料进行水资源评价及工程设计时,必须将实测径流还原为天然径流资料。根据该地区资料条件,雅鲁藏布江径流还原采用典型区法,先率定典型区的灌溉定额,并依据历年各水文站以上地区灌溉面积统计资料,计算还原水量,按典型区灌溉制度进行年内分配。     

黄河三门峡水库入库非汛期径流总量预报方法及其应用

三门峡水库入库非汛期径流总量预报是黄河水量年度分配和三门峡，小浪底两水库防凌和水量调度的重要依据。在分析黄河三门峡水库入库非汛期径流变化特点和影响因素的基础上，建立了龙门，华县，潼关等站非汛期径流总量预报模型，并将预报模型应用于近几年的实际作用预报。     

作物缺水条件下灌溉供水量最优分配

针对灌区水源短缺情况，建立了一种对有限水量在多种作物之间进行最优分配的两层分解协调模型：第一层为基于作物水分生产函数，求解单作物非充分灌溉条件下最优灌溉制度的动态规划模型；第二层为将有限水量在多种作物之间进行最优分配的动态规划模型实例计算表明，模型是合理可行的     

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。     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

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。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.