黄河秋汛简况

对黄河下游历年秋汛洪水的降雨、来水来沙特性以及秋汛洪水对黄河下游河道的冲刷作用进行了分析。在天然情况下黄河秋汛洪水发生的几率较大，可占花园口站5000m^3／s以上洪峰总数的1／3。龙羊峡等水库运用后，黄河下游秋汛洪水的洪峰与洪量均已大幅度减小，地区来源组成发生明显变化，上游来水比重减小，渭河、泾河、北洛河及伊洛河、沁河已成为下游洪水的主要来源区，经小浪底、陆浑、故县等水库调节后，黄河下游秋汛洪水的洪峰流量下降到2000—4000m^3／s。秋汛洪水的特点是洪峰流量较小、洪峰历时较长、洪峰水量较大、含沙量较低。秋季洪水一般在下游不会漫滩，冲刷均发生在主槽内，对抑制黄河下游主槽淤积、维持主槽的过洪能力十分有利。     

山东黄河“96.8”洪水演进及漫滩情况概述

1996年8月，黄河下游连续发生两次洪水，其中8月5日14时花园口站第一号洪峰流量为7600m3／s，13日4时30分花园口站第二号洪峰流量为5520m3／s，由于二号洪峰推进速度明显快于一号洪峰，在孙口站附近与一号洪峰汇合，形成单一洪峰向下推进，22日下午洪水安全入海。由于1号洪峰各站最高水位在花园口至夹河滩河段均超过历史最高值，致使140多年未曾漫滩的高滩也大部漫水。夹河滩至高村河段长82km，洪峰传播时间长达100小时，洪水传播速度每小时不足1km。10日0时洪峰到达高村站，洪峰流量削减到6200m3／s，相应水位为63．87m，接近历史最高的198…     

牡丹江区域中小河流水文站洪水相关影响因素分析

针对中小河流水文水位站建站时间短,资料系列短、水位流量关系不稳定等现状,目前中小河流洪水预报方法为分布式水文模型和预报系统。牡丹江区域范围内洪水主要为上游洪水造成,属于山区性河流,具有涨落快、流速大、洪峰停留时间短的洪水特性,峰形尖瘦、洪峰持续时间多约为20min。文章以铁岭河镇水文站为例,对洪水相关影响因素进行简要分析。     

福建省水利工程设计洪水计算的若干问题

本文讨论了福建省水利工程设计洪水计算的若干问题。包托：(1)关于设计暴雨C8与C7的倍比，(2)关于设计洪水统计参数的估计问题，(3)关于设计洪峰模数的特性和规律，(4)关于“面积比”方法推求设计洪水。作者就这些问题提出自己的观点和研究结果。     

龙羊峡水库建库前后水文设计成果对比

为掌握观测序列延长后的龙羊峡水库水文设计成果的变化情况,通过采用黄河上游流域实测的101年的径流观测资料、75年的洪水观测资料,运用皮尔逊Ⅲ型曲线对龙羊峡水库设计年径流、设计洪峰与设计洪量进行了分析计算.结果表明:采用延长资料的水库设计年径流与原始设计成果相差不超过2％;重现期在1000年一遇及以上洪水的设计洪峰、设计...     

适应“三大功能” 加快蓄滞洪区建设

河北省地处海河流域。全省共13处正式蓄滞洪区，其作为海河流域防洪体系的重要组成部分，起着削减洪峰、滞蓄洪水的作用。13处蓄滞洪区涉及保定、廊坊、邢台等7个设区市、30个县（市、区、农场），总面积6917km^2，居住人口327万，可蓄滞洪水总量126亿m^3，比全省18座大型水库总库容还多34亿m^3。     

未来十年内河北省或将迎来丰水期

上世纪60年代中期后，我省40多年未发生大洪水。1996年8月滹沱河出现了一次洪峰很高、历时较短的洪水；2012年7月大清河北支出现了一次历时短、洪峰较高的洪水。但总体来看这40多年处于平水、枯水期。     

2003年渭河洪水特性分析

受持续强降雨影响，2003年8月26日至10月13日；渭河连续发生了6次洪水过程。其中，华县站9月1日11时洪峰流量3570m^3／s，为1992年以来最大流量；相应水位342．76m，是有实测记录以来最高水位。在渭河首场洪水过程中，临潼至华县河段洪峰削减率高达53．1％，传播时间52．3小时，均为历史之最。初步分析认为，本次渭河洪水有以下特性：①水沙条件改变，河床淤积严重，形成了高水位洪水；②河道过流能力降低，比降变小，致使前期洪水削峰率大，传播时间长；③人类活动以及支流大堤的决口对削峰率和传播时间有影响；④洪水后期下游河道明显冲刷，漫滩流量增加，洪峰传播时间缩短。     

洪峰过程非稳定渗流管涌试验研究与理论分析

进行了洪峰过程和潮汐变幅对堤防发生管涌影响的非稳定渗流模型试验。与固定洪峰水头下的稳定渗流管涌试验结果相比，由于洪峰过程高水位历时较短，管涌险情发展的可能性显著减小，同时，管涌险情的发生也与土层的结构、压缩性和透水性有关。结合北江大堤洪峰模拟过程，讨论了砂模型试验的模型相似律和时间比尺的推算问题，给出了管涌险情发展时间的参考值。最后，通过可压缩非稳定渗流方程，导出了正弦型洪峰、潮汐或波浪在堤基中的传播速度、迟后时间、洪峰水头和能量衰减规律的计算公式，并得到试验资料的验证。     

黄河下游洪水期沙峰滞后特性研究

简要分析了黄河水沙异源的情况，指出沙峰滞后、洪峰与沙峰不同步是造成黄河下游涨冲落淤和小水大灾的主要原因。根据小浪底下游各站沙峰均滞后于洪峰的35场洪水，对沙峰滞后于洪峰的特性进行了剖析，建立了小浪底、花园口、夹河滩、高村、孙口、艾山、利津各河段沙峰滞后时间与上站洪峰流量、沙峰含沙量、洪水传播速度、悬移质泥沙群体沉速之间的回归方程，可以用来查补延长沙峰滞后时间，为下游各站沙峰传播时间的准确预报提供依据。     

The influence of hydro‐climatic and anthropogenic effects on the long‐term variation of commercial fisheries in a large floodplain river

This study deals with the effects of climate fluctuations and anthropogenic impacts on fisheries of Paraná River over the last 100 years. It is the first attempt to appraise the influence of hydro‐climatic and anthropogenic variables on the population changes of the most important inland fisheries of Argentina. Datasets covering more than eight decades (1935–2016) of a number of frequent and abundant commercial species inhabiting the main channel as well as the large floodplain of Paraná River were used. Our results suggest that fish catches and structure changed over time. Long and short‐term changes and reductions were closely related to fluctuations of 18 hydro‐climatic variables. Positive effects on the ichthyofauna were recorded during humid periods (1930–1940 and 1970–2000), when the frequency of large spring–summer floods increased. An increase in anthropic impacts (accounted for with nine variables) were recorded during the last two decades. We highlight the usefulness of the approach to support the management of the resources, ensuring sustainability of commercial fish assemblages and the long‐term conservation of biodiversity in big rivers.     

基于BAS算法的河渠突发水污染溯源

为了在河渠突发水污染事件发生后快速识别污染物的源项信息,结合正向的质量浓度过程与逆向位置信息之间的关系,实现污染物源项的解耦,确定了质量浓度与位置概率密度函数之间的相关关系以及质量浓度与正向质量浓度概率密度函数之间的关系,构建了水力学模型,并利用天牛须搜索(BAS)算法对水污染源项进行求解。数值模型仿真结果表明:该水力学模型与BAS算法的结合有效地降低了计算量,计算得到的源项信息与实际情况基本符合,精度较高;与粒子群算法相比,BAS算法收敛速度快,运算量小。     

The politics of water transfer between South Africa and Lesotho: Bilateral cooperation in the Lesotho Highlands water project

Abstract

This paper demonstrates that cooperation over international rivers can be achieved through situations where benefits of river development create bilateral dependence between basin states. The case study of the Lesotho Highlands Water Project, a bilateral water transfer in the Orange River basin between South Africa and Lesotho, is examined. Historical analysis of the negotiations leading to the project treaty agreement show that issues of apartheid and the Cold War heavily influenced the riparian relations between the two states. At times, the project faced the threat of abandonment due to deteriorating diplomatic conditions. However, the project was realized because South Africa and Lesotho not only shared the material benefits of the project, but also gained politically from committing to it. These political benefits are influential in creating interdependence between the basin states in order to ensure the reliability of bilateral cooperation.     

LONG‐TERM TAXON‐SPECIFIC RESPONSES OF MACROINVERTEBRATES TO DAM REMOVAL IN A MID‐SIZED SWEDISH STREAM

Dam removal to restore ecologically impaired rivers is becoming increasingly common. Although the target often is to facilitate fish migration, dam removal has also been assumed to benefit other types of organisms. Because few studies thus far deal with effects of dam removal on stream macroinvertebrates and because results have been equivocal, we investigated both short‐ and longer‐term dam‐removal effects on downstream macroinvertebrate communities. We did this in a before‐and‐after study of the removal of a dam located in a south Swedish stream. We sampled the benthic fauna 6 months before dam removal and both 6 months and 3.5 years after the dam was removed. We compared species composition, taxonomic richness, total densities and densities of macroinvertebrate groups before and after dam removal and between downstream and reference sites. We found that dam removal reduced some macroinvertebrate taxa at the downstream site, but we found no effect on community composition. Although this corroborates results from previous short‐term studies, we also found a reduction of taxonomic richness and that some dam‐removal effects persisted or even increased over time. The most likely explanation for the suppression of benthic macroinvertebrate richness following dam removal is a significantly increased sediment transport from the former reservoir and a subsequent loss of preferred substrates. Our results indicate that adverse dam‐removal effects may be long lasting but taxon specific. We therefore call for longer‐term studies on a variety of organisms to better understand how dam removal may influence downstream macroinvertebrate communities. Copyright © 2012 John Wiley & Sons, Ltd.     

基于函数依赖的关系模式分解方法分析

在数据库设计中，关系模式的规范化过程是通过对关系模式的分解来实现的。把低一级的关系模式分解为若干个高一级的关系模式，这种分解不是唯一的。逻辑数据库设计主要是以关系规范化理论为基础，分析关系模式中的数据依赖，通过投影分解，消除不合理的数据依赖。对基于函数依赖的关系模式的分解方法进行了分析。     

堆石料长期变形的室内试验研究

堆石体存在流变,不仅与荷载有关,而且与干湿循环有关。堆石坝的长期变形观测资料也表明,雨季产生的变形常显著高于非雨季。本文通过室内试验模拟日晒雨淋引起的干湿循环作用,研究等围压荷载作用下干湿循环对堆石料长期变形的影响,并依试验所揭示的变形随干湿循环而变化的规律,建立了计算变形的近似公式。结果表明,干湿循环作用引起的堆石变形是不可忽视的,它随循环次数的增加呈非线性发展,并与围压呈正比。在计算堆石料长期变形时,除了考虑荷载作用的流变变形,还需根据年降雨的循环次数计算堆石料长期的变形。     

A PRESUMPTIVE STANDARD FOR ENVIRONMENTAL FLOW PROTECTION

The vast majority of the world's rivers are now being tapped for their water supplies, yet only a tiny fraction of these rivers are protected by any sort of environmental flow standard. While important advances have been made in reducing the cost and time required to determine the environmental flow needs of both individual rivers and types of rivers in specific geographies, it is highly unlikely that such approaches will be applied to all, or even most, rivers within the forseeable future. As a result, the vast majority of the planet's rivers remain vulnerable to exploitation without limits. Clearly, there is great need for adoption of a “presumptive standard” that can fill this gap. In this paper we present such a presumptive standard, based on the Sustainability Boundary Approach of Richter (2009) which involves restricting hydrologic alterations to within a percentage‐based range around natural or historic flow variability. We also discuss water management implications in applying our standard. Our presumptive standard is intended for application only where detailed scientific assessments of environmental flow needs cannot be undertaken in the near term. Copyright © 2011 John Wiley & Sons, Ltd.     

Occurrence of Alternative Fecal Indicators and Enteric Viruses in Michigan Rivers

Fecal contamination has been a leading problem associated with the impairment of surface waters in the State of Michigan. However, the source of the contamination and the possible presence of pathogens has not been adequately addressed. In this preliminary study, nine major rivers located in the Lower Peninsula of Michigan were investigated for the presence of fecal coliforms, Escherichia coli, enterococci, coliphage, and enteric viruses. Five sites (56%) exceeded the allowable limits set for recreational waters based on E. coli concentrations for the State of Michigan. Three (33%) of these sites (Grand, Kalamazoo, and Rouge rivers) tested positive for the presence of viable enteric viruses. The presence of enteric viruses and elevated levels of microbial indicators suggest that these waters may pose a threat to the health of individuals using them for recreational activities.Several new genotypic and phenotypic characterization methods have emerged that have the ability to define human and animal sources of fecal indicators. Previously, we developed a host-associated molecular marker for Enterococcus faecium, which is human specific and targets the sequence for the enterococcal surface protein (esp). When the nine rivers were screened for the marker, two (Grand and Rouge rivers) were found to be positive, implying the presence of human fecal contamination. This study suggests a preliminary approach for validating the use of molecular markers for identifying sources of fecal pollution in the Great Lakes Region and the human health risks associated with pathogenic viruses.     

河流出口处短周期地貌变化的观测与模拟

中小型河流出口处地形变化的发生频率要比大河的高。这主要是由小河和大河的径流量及纳潮量的不同所引起的，尽管这两者之间波浪的作用力差不多。因此，对于小河的河口管理而言，更加频繁的现场监测是十分必要的。然而，目前还没有一种可以高频率地获取地形变化信息的监测系统。介绍一种利用安装在河口处的自动数码相机对中小型河流河口地形变化进行监测的方法。通过沙嘴左岸及右岸的数据，可以确定河口处的宽度。通过这一测量方法，在数值模型中所使用的参数也可以确定下来。     

基于RVA阈值区间集成的河道内生态需水计算与应用

在对河道生态需水特点进行分析和总结的基础上,提出了基于变化范围法和多种水文学法计算成果的河道内生态需水计算方法——下包线法,建立了考虑径流资料精度的评价体系。结合一致性审查、河道内生态需水计算和评价,构建了考虑径流非一致性的河道内生态需水计算框架,并应用于陕西省引汉济渭工程。结果表明:河道内生态需水过程具有波动性、季节性、时效性和区间性；在生态需水阈值区间内,下包线法同时满足维护河道生态和保证兴利效益的目的,可在较高生态需水标准基础上进一步压缩生态需水总量；下包线法和Tennant法中Tennant-好、Tennant-差所得生态需水过程分别为引汉济渭工程理想、适宜和最低生态需水过程。