声学多谱勒流速剖面仪流量测验精度分析

介绍了声学多普勒流速剖面仪测流技术的测流原理,并在黑河莺落峡水文站龙电渠测验断面与传统流速仪进行了对比测量。结果表明：①采用声学多普勒流速剖面仪测量流量,能够达到实时监测的目的,但在流沙河床、有磁场影响和水深较小的情况下测验精度不高,同时,在测量断面必须有桥或相应的牵引设备方可进行施测,使用时必须准确输入仪器工作所需的测量断面的有关参数;②采用声学多普勒流速剖面仪测量流量时,在平均水深小于2m的河流(或渠道)上,单元高度设置为10cm比设置为26cm的测验精度高;③测船航行速度越慢,往返测量的误差越小,流量测验精度越高,和流速仪法测量结果之间的系统偏差越小。     

三峡工程明渠截流水文测验测船设计与实践

三峡工程明渠截流水文测验分别选择了"ADCP无人测艇法"和"ADCP动船法".选用风云2号轮作机动测船.该船船长28 m、船宽5.5 m、航速22 km/h,电动液压舵机,备有专用水文绞车设备,双车双舵,船体为球型涡尾,具有较好的急流稳性和操纵性能.风云2号水文测船采用GPS全球定位系统定位,将测验断面和测验垂线预置在计算机内,通过显示屏在驾驶室显示,驾驶员操纵测船稳定在测验断面和测验垂线上.水文测船及时、准确、安全地为截流工作的科学决策和水力学模型验证收集到了相关的水文资料.     

ADCP在永庆反调节水库闸门泄流曲线复核上的应用

本文首次使用ADCP完成永庆反调节水库闸门泄流曲线复核。通过在闸下固定三体船搭载ADCP完成闸下流量定点施测,同时在下游450 m无支流汇入的固定断面使用走航式ADCP施测断面流量,完成对闸下流量的校测。本文选取符合标准的实测流量数据绘制水位流量关系,依据《水文资料整编规范》要求,完成定线精度检验和关系曲线检验,并最终通过水量平衡法核验,证明了使用ADCP率定闸门泄流曲线是可行的。     

浅谈水下抛石施工中的测量工作

利用GPS 测深仪的方法进行原始水下地形测量,合理地划分抛投网格,做好基线桩和方向桩的测设,实现定位船的准确定位及石料的网格抛填,及时检测抛石网格完成后的断面,对缺陷部位进行补抛,并总结水下抛石测量的经验。     

GPS卫星定位技术在水库库区测量中的应用

闹德海水库库区森林遮视严重，很难进行常规的三角测量，而采用ＧＰＳ定位技术，仅用很短时间就完成了库区横断面端点联网定位任务，作业过程中各项指标均优于规范规定的精度要求，实践证明，ＧＰＳ定位技术可以满足水库断面测量，地形测量，精度工程测量的要求。     

大水深测量校正方法研究与应用

水库水深测量精度直接关系到水库的防洪安全与蓄水兴利。现有回声测深仪无法应对大水深施测的情况，且测量受到水库水温分层影响。利用回声测深仪配合校正标进行大水深测量的校正方法，能够精确检测到回声测深仪水深测量的误差及差值、系统延时问题等，通过与各级校正标的真值比较、修正，能使测值近似真值,且使误差控制在容许范围内。介绍了水深校正标基本原理、操作方法和步骤以及在水库测深中的应用。     

雷达结合罗经测量水边界集成技术研究

目前,河道水下地形测量中水边界一般采用测船定位或人工肩负GPS现场施测,不仅投入人员设备多、作业时间长,严重影响了水下地形测量的进度。雷达结合罗经和GPS水边界测量集成系统对不同的水边界和水中建筑物测量有较好的辨识能力,实现了水道水边界连续测量和表达,施测精度满足《水道观测规范》1/10 000水下地形测量精度要求,并得到了成功应用。     

无人船系统在富春江水库及其回水区的水文应用

简单介绍对无人船系统的发展及无人船测量作业流程。通过其对富春江水库及回水区水文测验的成功应用,进一步论述无人船系统测量水下地形和流量的作业过程。本次水下测量,无人船累计航行30 h,总航行里程约24 km,对6条河流计120个水下地形断面及6条流量断面进行施测,并对实际应用效果进行分析。结果表明,无人船系统搭载相关仪器能够满足水下测量数据准确度的要求,与人工测量相比,更好地满足了调查区域复杂水域情况,从而大大提升工作效率及安全系数。     

超声波测深技术在溪洛渡枢纽水文监测中的应用

水深测验的精度直接影响到流量测验的准确性。基于超声波测深技术研制出HSH-IL型测深仪,它可采用缆道钢绳和水体作为测量信号传输通道,不需要专门导线;同时采用信号迭加概率分析技术,提高超声波测深精度和可靠性。在金沙江溪洛渡水电站截流施工中,根据水深流急、施工干扰突出的特点,在相应水文监测断面上布设HSH-IL型测深仪施测,满足了流量测验的可靠性和时效性要求,取得了较好的效果。     

极坐标法在高洪流量测验中的应用

流量测验设施建设受测验河段的断面控制影响,测洪能力有一定的局限性,施测大洪水时,当流速仪测验设备及浮标投放设备冲毁或发生故障,河中漂浮物较多时,测船无法下水,采用流速仪法和均匀投放浮标法测流均已失效,利用天然漂浮物浮标,用极坐标法测定漂浮物浮标流速,是施测较大洪水既可行又安全的方法。     

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。     

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.     

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.     

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.     

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。     

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。     

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.     

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.     

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。