李溪拦河闸下游消能工除险改造研究和实践

拦河闸下游河道河床下切、水位降低后,改变了其下游消能工运行的水文条件,会造成拦河闸下游消能工破坏,危及工程的安全运行。通过对流溪河李溪拦河闸下游消能工一、二期除险加固改造的水力模型试验成果的总结和分析,介绍了该工程下游消能工除险改造优化方案和应用情况,可供类似工程设计和运行参考。     

拦河闸下游两级消力池布置和计算研究

通常根据拦河闸泄洪水力条件、闸址地形和地质条件、两岸翼墙和堤围的安全、工程施工和投资等,拦河闸下游可选择设置一级或两级消力池。本文对拦河闸下游两级消力池的布置和水力计算方法进行了分析,提出了相应的布置和计算方法:1首先确定一级消力池水平段池底高程,计算消力池末端尾坎的合理高度和水平段池长,使一级消力池内形成稳定的水跃;2根据拦河闸闸址下游河道水位条件,在满足二级消力池出流与下游河道水流为缓流衔接的条件下,初拟二级消力池末端尾坎顶高程,计算出消力池池深和池长,使消力池出流平顺与下游河道水流衔接。本文成果得到了水力模型试验研究实例的验证,可供类似工程设计参考。     

流溪河李溪拦河闸的消能问题及改造研究

由于流溪河李溪拦河闸下游河床下切、下游水位降低,造成拦河闸下游消能工损毁,严重危及工程的安全运行。该文结合流溪河李溪拦河闸下游消能工加固改造工程的水力模型试验成果,介绍了该工程下游河道水位下降后的下游消能工改造优化方案和原型运行观察情况,可供类似工程设计和运行参考。     

西溪拦河闸下游消能工出险分析和改造研究

潮州供水枢纽工程西溪拦河闸建成运行后,其消力池下游海漫段遭受到较严重的冲刷破坏。 根据西溪拦河闸工程布置和出险的泄流水力参数,对其下游消能工出险的水力条件和原因进行计算和 初步分析,并介绍其除险改造方案试验研究成果和运行情况。研究表明,西溪拦河闸消力池下游海漫段 出险与其闸下游河道水位降低、海漫段的结构和质量等因素有关,拦河闸下游消能工除险改造试验研究 成果是合理的。     

东山拦河闸加固改造工程消能研究

由于东山拦河闸下游消力池遭受破坏,且下游河道河床下切、水位降低,需对拦河闸下游消能工进行加固改造。通过水工模型试验,在东山拦河闸现状下游消力池加固改造的基础上,为了确保消力池下游海漫段的安全运行,在海漫段上设置消力墩和消力坎等辅助消能工。研究表明:消力池下游海漫段上设置了消力墩和多级消力坎之后,海漫段的泄流消能率最高可达约50%,确保了出池水流较平顺地与下游河道水流衔接。研究成果得到了工程建设的采用,可供类似工程设计和运行参考。     

潮州供水枢纽东溪拦河闸消能工除险改造试验研究

潮州供水枢纽东溪拦河闸下游河床下切之后,河道水位明显下降,拦河闸下游消能工无法满足消能防冲的要求,危及工程的安全运行。东溪拦河闸除险改造工程对原消力池进行改造,并在其下游布置二级消力池,经水力模型试验优化后,妥善解决了拦河闸下游消能防冲的问题。     

低水头拦河闸下游一、二级消力池的布置

为了解决低水头拦河闸下游河床下切、河道水位下降造成下游消能工无法正常运行的问题,需要对拦河闸工程下游消能工进行除险改造或重建。基于广东省3座拦河闸除险改造和重建工程的水力模型试验研究成果,对低水头拦河闸下游两级消力池的布置进行研究,提出加高一级消力池尾坎顶及在下游陡坡段设置外凸型阶梯跌坎等优化措施。试验结果表明,采取上述措施可大幅度提高消力池水流消能率,简化消能工设施,节省工程投资。     

潮州供水枢纽工程西溪拦河闸消能工除险改造试验研究

由于潮州供水枢纽拦河闸下游河床下切，下游河道水位明显下降，造成拦河闸下游消能工出险。根据潮州供水枢纽西溪拦河闸下游消能工除险改造工程的水力模型试验资料，介绍拦河闸下游消能工除险改造优化方案试验研究成果及运行情况，供类似工程设计和运行参考。     

大坡山拦河闸下游消力池池深的计算和分析

低水头拦河闸下游消力池池深的主要影响因素有闸上游水位、泄流单宽流量和下游河道水位等,工程设计中,可根据泄流单宽流量、下游河道水位、下游河道地形等,先确定消力池末尾坎顶高程,然后根据不同的运行水文条件组合计算出相应的池深值,以其最大值作为池深设计值。该文通过大坡山拦河闸下游消力池尾坎顶高程、池深的计算和分析实例．验证了上述方法。     

潮州供水枢纽西溪拦河闸下游水位下降影响研究

近年来,由于潮州供水枢纽西溪拦河闸下游河床下切、下游河道水位下降,对枢纽工程运行产生了不同程度的不良影响。对此在对历年西溪拦河闸下游河道水位与流量关系变化总结和分析的基础上,对下游河道水位下降对西溪枢纽拦河闸、电站、船闸等建筑物的影响进行分析,介绍枢纽工程现行采用的改造工程措施,并对今后改造的方法进行探讨,供工程设计和运行参考。     

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.     

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.     

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.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

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.     

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。