枕头坝一级水电站正常蓄水位比选分析

正常蓄水位是确定水电站规模和水库淹没影响范围的重要参数。针对枕头坝一级水电站的开发任务和工程特点,综合考虑水库淹没、环境影响、工程建设条件与枢纽布置及经济指标等多方面影响因素后,从拟定的4个正常蓄水位比选方案中,选定枕头坝一级水电站正常蓄水位为624 m,侧重考虑了水库淹没与库区经济、社会的协调发展,体现了大渡河水电开发具有合理开发利用水能资源、开发与保护并重、努力实现多方和谐共赢的水电开发新特点。     

关坝水库蓄水位选择分析

决定水库蓄水位高低的因素主要有工程环境、水库最高蓄水位、最低蓄水位、水库下游蓄水量及工程投资和淹没损失等,文章通过对关坝水库水位选择进行探讨,从充分利用水资源方面考虑,随着水库正常蓄水位的增加,水位为817-829m时水库供水量的增加与水位关系基本为线性增加关系,正常蓄水位越高供水量越大。从淹没损失方面考虑,由于825m高程以上分布有村寨,水位抬高后将导致淹没投资大幅增加,最终选择关坝正常蓄水位为823m。     

花甲水库正常蓄水位选择

正常蓄水位是水库和水电站最重要的设计参数之一,是确定拦河坝高度、水库容积、利用水头和发电能力的基本依据;对水工建筑物的工程量、水库调节性能和水头的利用关系极大,对水库和水电站的建设工期、投资、动能经济效益以及水库淹没损失等均有重要影响。文章以花甲水库工程挡水坝的正常蓄水位选择为例,从水库供水量、水库淹没、工程投资对水库正常蓄水位的影响等方面做简要分析论证。     

水库淹没调查在水利水电工程建设中的重要性

1水库淹没实物指标调查的意义工程建设规模的确定,是以经济、社会、环境效益为最大,而淹没损失相对较小为条件。一般在水库工程建设的前期阶段,都要对不同设计蓄水位做方案比较。调查不同正常蓄水位的淹没实物指标,把水库淹没、移民安置与当地社会经济、财力、生态环境等诸多因     

西藏金河流域瓦托水电站正常蓄水位选择

水电站正常蓄水位的选择,不仅需要考虑工程建设条件、生态环境、水库淹没影响、投资及动能经济等因素,还应考虑与上下游水电站的衔接以及联合调度产生的综合效益。以西藏金河流域瓦托水电站为例,重点介绍与上游勒珠水电站衔接时,以其动能、经济指标和在电网发挥作用的综合效益,来选定正常蓄水位。由于瓦托水电站库区淹没影响小,无国家珍稀动植物分布,无通航要求,电站正常蓄水位的确定主要考虑梯级水库水位銜接、经济效益、电网调峰等因素。经综合比较,最终确定瓦托水电站最优正常蓄水位为3 315 m。     

珊溪水库工程正常蓄水位选择

通过对两个正常蓄水位方案发电量、投资、水库淹没指标等的分析，并对方案进行经济比较，综合分析确定珊溪水库正常蓄水位。     

已建坝正常蓄水位调整论证方法研究

已建坝正常蓄水位调整是挖掘水库兴利能力的有效途径，但目前缺乏明确可靠的论证方法。采用水文学、大坝安全、大坝风险及生态环境理论，研究已建坝正常蓄水位调整必要性的影响因素及特征，分析调整后水库防洪安全、工程安全、库区淹没、库岸结构、库区水环境所受影响特征，提出了正常蓄水位调整必要性论证的6个一级、14个二级指标体系，以及调整后影响论证的7个一级、23个二级指标体系及其分析方法，构建调整方案风险效益分析方法，并应用于杭州青山水库正常蓄水位调整论证。结果表明：针对青山水库将正常蓄水位提高2.0 m的推荐方案，提出的论证指标体系和论证方法合理有效。     

胜利水电站正常蓄水位方案选择

<正>常蓄水位选择是水电站设计工作的一项重要任务。本文以胜利水电站为例,分别从梯级电站水位衔接、水能资源利用、水库淹没和工程经济评价四个方面出发,阐述了水电站拦河坝正常蓄水位的选择过程,分析了影响正常蓄水位的制约因素,并通过合理比选,最终确定了胜利水电站的正常蓄水位方案。     

乌东德水电站正常蓄水位抬高初步研究

成昆铁路的提速改造为修改乌东德水电站原订的950 m正常蓄水方案提供了有利契机,可使乌东德水库正常蓄水位抬高几十米。从水库正常蓄水位抬高对成昆铁路、及攀枝花市防洪及水环境、雅砻江口生态环境的影响以及水库淹没指标、工程经济效益等方面进行了综合分析。分析结果表明,乌东德水电站正常蓄水位提高至975 m,可获得较好的经济效益,且对环境、防洪、移民的负面影响不大。     

花园水库淹没影响范围确定方法探析

水库淹没影响范围包括水库淹没区和因水库蓄水而引起的影响区。水库淹没区包括正常蓄水位以下的经常淹没区和水库正常蓄水位以上因水库洪水回水、风浪、船行波、冰塞壅水等产生的临时淹没区。水库蓄水引起的影响区包括浸没、坍岸、滑坡、内涝、水库渗漏等地质灾害区,以及其他受水库蓄水影响的区域。     

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.     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

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。     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

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.     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.     

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。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

泥石流危害与防治

泥石流介于流水与滑坡之间的一种地质现象,其具有突然爆发、阵性、能量大的特点,来势凶猛,破坏力极强,给人民生命财产造成极大的损失和破坏。掌握其发生规律和特点,进行预报和防治是非常必要的。