小北干流有坝放淤引水时机及规模分析研究

利用龙门断面近20年的实测水文、泥沙及龙门-潼关河段的冲淤量资料，分析研究小北干流有坝放淤的引水引沙条件、引水时机及引水规模。研究成果表明：当龙门断面流量大于400m^3／s、含沙量大于40kg／m^3、泥沙中值粒径大于0．025mm时，开始引水，淤区引粗泥沙较多。根据设计的来水来沙条件，满足上述引水引沙条件，并考虑引水闸规模投资等，确定引水规模为800m^3／s，则年平均引沙量为1．22亿t，粗、中、细沙的引沙量分别为0．27亿、0．35亿、0．60亿t。     

中小型水库工程施工合同管理实践

三门峡市槐扒西段村水库工程是豫西农业开发项目中的一个子项目，其目的是作为槐扒黄河提水工程的调蓄水库，即当黄河含砂量小于50kg／m^3时，由黄河提水直接供给工农业用水；含砂量大于50kg／m^3时，由水库调蓄供水。水库由大坝、溢洪道、泄洪洞和输水洞组成，水库库容为3千万m^3，最大坝高45．6m。     

阜蒙新河闸水下工程建设进度控制

一、工程概况 阜蒙新河闸工程为1级建筑物，主要功能有防洪、排涝、蓄水和通航等。防洪闸规划设计排洪流量195m^3／s，闸室分3孔，中孔为通航孔，孔口净宽10．0，两边孔净宽均为8．0m。闸室顺水流方向16．0m，闸底板高程21．0m，底板厚1．1m，两边孔胸墙底高程26．0m，中墩厚1m，边墩厚0．8m，墩顶高程为30．5m。主要工程量：土方开挖和回填2．5万m^3，石方3554m^3，钢筋制安213t，新建混凝土2881m^3．     

黄河下游不同调控洪水下河道水位的变化

在基本相同的水量条件下，设计了4种出库洪水方案，其洪峰流量分别为2600、4000、5000、6000m^3/s，利用实体模型试验研究了小浪底水库相同水量不同调控洪水过程中黄河下游特定河段水位的变化情况，比较了各方案洪水前后相应平峰流量的水位降幅。结果表明：①各方案均表现出随着历时的增加沿程各断面同流量水位降低；②总来水量和来沙量基本相同时，不同设计洪水前后同流量下水位降幅与设计洪水洪峰流量成正比；③总来水量和来沙量基本相同，设计洪水洪峰流量超过5000m^3／s时，同流量下水位降幅不明显；④漫滩水量增大时，洪峰前后水位降幅减小。     

引滦入津尔王庄自流道闸门自动控制系统的应用

天津市水利局引滦工程尔王庄管理处所辖上游输水明渠设计水深3m，底宽22m，左右坡度1／3，纵坡度1／20000．设计流量50m^3/s。尔王庄明渠泵站是通过明渠向大张庄泵站输水为海河补水的泵站，暗渠泵站发生故障时，明渠泵站抽水与大张庄泵站联合运用向暗渠输水。明渠泵站旁设有自流道．总长210．79m．2孔3．5m×3m．设计流量12m^3／s，校核流量20m^3／s。     

大朝山水电站机组进水口前冲沙建筑物设计

１工程概况大朝山水电站位于云南省临沧地区云县和思茅地区景东县交界处的澜沧江上，枢纽装机容量１３５０万MW，最大坝高为１１１．０m，总库容为９．３３亿m３．多年平均输沙量为５４９３万t，多年平均含沙量为１．３１kg／m３，汛期（６～１０月份）来沙量占全年总沙量的９５．８％，其中７～９月集中了全年来沙量的７７．２％．水库采用“蓄清排浑”的运行方式，即６～９月库水位降至汛期限制水位运行，使汛期主要沙峰沙量出库，控制水库的泥沙淤积高程；１０月以后来沙减少，水库开始蓄水至正常水位８９９．００m．大朝山水电站水库淤…     

河口、海岸环境下床沙输运的初步实验研究

实验量测在水深0．5m的情况下波浪、水流通过水平沙床所产生的床沙输移。波高0．15m，周期分别为1．4和2．0s。首先量测纯波浪下的床沙输移，然后量测波流共同作用下，水流与波浪行进方向一致其稳定速度分别为0．02、0．04，0．06m/s时的床沙输移。结果，两个沙槽所得的总沙量在波周期2.0s时最大，净输水得在波周期1．4s时最大，将波叠加在速度为0．2m/s的水流上时，两种波型的净输沙率都增加2倍，水汉为0．04m/s和0．06m/s时两种波型的净输沙率分别都减少。     

中国第二大水利枢纽金沙江溪洛渡水电站成功截流

溪洛渡水电站截流从11月7日上午9时许正式开始进占。随着龙口缩小，江水逐渐从左、右两岸的5个导流洞分流，龙口流量开始从3500m^3／s逐步减少。至下午4时，截流戗堤口门宽32．04m，水面宽27．18m，龙口流量592m^3／s，龙口最大流速9．2m／s，导流洞分流比83．2％。为确保截流工程成功，对施工方案做了最保守的设计，以6000m^3／s的流量作为方案制定标准，并按设计量的1．5倍准备了截流投物量。     

甲供主材前提下的相关结算问题初探

1工程概况 台儿庄泵站工程是南水北调东线第一期工程的第七级泵站，位于山东省枣庄市台儿庄区境内，设计流量125m^3／s，设计扬程4．53m，平均扬程3．73m；有5台3000ZLQ32—5．2型立式轴流泵（其中1台备用），单机设计流量31．25m^3／s，配套电机功率为2400kW，总装机容量12000kW。     

金家坝水电站水轮机参数选择

金家坝水电枢纽工程位于重庆市酉阳县境内，坝址位于乌江的支流甘龙河下游，其控制流域面积1059km^2、占全流域面积的63％，多年平均流量26．9m^3／s，多年平均含沙量为0．698kg／m^3。水库正常蓄水位445m、死水位407m，调节库容1．125亿m^3——具有年调节性能。根据甘龙河的流域规划，该河流梯级电站分四级开发，即营盘岭、堰塘湾、金家坝和五堆电站，金家坝水电枢纽工程为第三级。     

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。     

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。     

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.     

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.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

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.