枢纽互通区平面二维水流数值模拟研究

从平面二维水动力学方程组出发,建立了二维水流运动的基本方程,模拟出桥区河道水流流场,并与实测成果比较,该数学模型与实际流场吻合较好,经综合分析,工程建设前后的水流流态基本一致,引起河道地形的变化局限在工程附近水域,对通航水流的影响很小。     

河道工程建设与管理思考

当前,随着中国经济建设的发展,人们更加注重生活质量与生活环境的双重提高。河道作为一项基本的运输渠道和天然水流通道,在人们的生活中发挥着不可替代的作用,然而随着当前人们对河流的不合理利用,给河道的发展带来不利影响。主要分析河道工程建设和管理中存在的问题,提出了加强河道工程建设与管理的策略。     

河流改道引起不同水期地下水流场变化的数值模拟分析

所研究的河流位于我国北方。基于景观和生态的原因,拟对河流的局部河段进行改道。为了解河流改道后引起地下水流场的变化程度,利用当地的水文地质资料,分别对丰水期、和枯水期两个水期的改道前和改道后的地下水流场进行了数值模拟、对比和分析,并对地下水流场变化引起的地基应力及变形的变化进行了分析计算。分析结果表明:河流改道后,对不同水期地下水流场的影响程度不同,导致其附近已有建筑物的地基产生的应力增量和变形增量也不同。并且如果河流仅仅是局部河段改道,其对周围地下水流场的影响很小,对周围建筑物的地基稳定性影响也很小。     

嘉兴地区中小河流河道整治工程地质勘察技术探讨

近几年,嘉兴市中小河流整治工作如火如荼地展开。那么,如何提高河道的工程地质勘察技术水平呢？本文概述了嘉兴地区中小河流河道整治工程的现状,对嘉兴市河道整治工程地质勘察过程中的一些技术问题进行了分析和探讨。     

黄河头道拐断面河道冲淤变化及河床演变特征分析

针对近年来黄河内蒙段防洪、防凌形势严峻,河槽萎缩日益加重等问题,分析了黄河内蒙段头道拐断面河床冲淤演变特征。通过同流量水位变化,分析该河段河床冲淤变化发现:该河段在2008年以前呈微淤状态,在2008年以后呈冲刷趋势,并有"凹岸冲刷、凸岸淤积"的特点;依据头道拐水文站的水文资料及遥感数据影像的分析,分别以1987年头道拐河道横向水深变化及平面河势变化为基础分析了2006、2010、2014年头道拐河道的相应变化,发现在水流作用的影响下,弯曲河道凹岸的冲刷速度大于凸岸的淤积速度,河道形成旋涡回流。以上结果均是在水流条件及外界条件的共同作用下造成的,水沙条件变化必将导致河道演变,研究水沙条件变化规律有利于充分认识河床演变规律,为今后解决防洪、防凌问题提供依据。     

黄河宁夏卫宁河段一维水流数学模型应用研究

黄河宁夏卫宁河段河势变化复杂,断面型式多为复式断面,漫滩水流的滩、槽水力要素存在明显差别。采用HEC-RAS软件划分主槽和左、右滩地,分滩、槽设定糙率等参数,建立卫宁河段一维水流数学模型,推求的主槽、滩地的水深、流速、分流比等反映了河道实际水流结构,对河道整治工程具有重要的实际意义,为黄河以及其他断面型式复杂的天然河道设计水面线计算提供了重要依据。     

河道公园综合提升改造工程设计探讨

河道公园综合提升改造工程能通过水质提升、景观打造等方式改善河流流域水环境质量和周边居民居住条件,是城市生态水系建设的重要环节。本文以河南省某市河道公园为研究对象,分析了影响该河道公园景观效果的因素,针对该公园给水和污水系统提出不同的改造措施,并对比分析了其优劣性,最终给出相应的设计方案。     

长输水管线施工技术分析

长输水管线的施工质量直接决定了其运用情况,某些工程输水管线距离长,面临的水流条件繁杂多样,这些都给长距离输水工程带来了重重困难。     

城市河流防洪与生态景观设计探讨

城市河流是城市系统的重要组成部分[1],随着城市化进程的推进,河道被侵占、水质污染、水环境退化等问题日益突出,严重影响城市经济社会的可持续发展。近年来,城市河流治理逐渐成为一项重要课题,河道治理措施研究的重心也从河道行洪、航运等的基本功能向重视河流的生态治理与修复转变。本文以过芸溪流域河道治理工程为例,探讨河道防洪与城市景观工程相结合的城市河流治理措施。     

生物飘带在河道水质净化中的应用及分析

河道水质原位改善修复可有效降低湖泊污染负荷并提高其环境容量。采用生物飘带技术进行河道水质净化处理,经自然挂膜,生物飘带表面生物相较为丰富,细菌、原生和后生动物共同发挥作用。工程前期对COD、氨氮去除量分别可达1 608、246 kg/d,达到了河道水流经过各生物飘带处理段后COD降解1 000 kg/d、NH3-N降解140 kg/d的处理要求,实现了污染物质的有效去除。工程运行效果表明:基于生物飘带的河道原位修复技术可对污染河流实现有效处理。     

重庆市江水源热泵技术应用基础数据库建设

为研究重庆地区长江和嘉陵江江水的水温、水质、水位的年变化规律,开展了全年逐月测试。结果显示,两江水温在竖直断面上基本保持不变,相对于嘉陵江而言,长江江水温度具有夏季较低、冬季较高的特点,较嘉陵江更适合作冷热源;两江江水均要解决浊度大的水质问题,长江江水还须解决铁离子含量偏高的问题;重庆地区两江的水位变化幅度分别约为3.8,5.4m,且变化频繁。     

阆中市嘉陵江四桥索塔墩承台钢套箱安装

跨江大桥常因河面较宽桥墩需设于水中,出于美观需要,主墩承台大多低于水位,承台需要钢围堰、钢套箱等隔水措施才能实施。而钢套箱体型大、重量大,受桥墩位于河中限制,需采用分节段吊放拼装就位,连接成整体下落。如何安全吊装、准确就位、高精度的对接是钢套箱成败的关键。阆中市嘉陵江四桥索塔墩钢套箱实施过程中周密策划达到设计要求,完成效果良好,为钢套箱实施提供点滴参考。     

Impact of combined sewer overflow on urban river hydrodynamic modelling: a case study of the Chicago waterway

Combined sewer overflow (CSO) can be a critical inflow source for urban rivers during storm events. This paper presents a case study of the Chicago waterway. A three-dimensional (3D) river hydrodynamic model was developed and integrated with an urban rainfall-runoff model using the Open Modelling Interface (OpenMI). Both the effects of CSO discharge on river and river water levels on CSO outlets were considered by the integrated model. A historical storm, which was similar to a 100-year return period rain event, was simulated and compared with field measurements. This study highlights the necessity of quantifying CSO for hydraulic modelling of urban rivers under extreme storm event conditions, and shows that an integrated hydrologic and hydraulic approach can be used to address this challenge. The 3D river hydrodynamic model can deal with the complex hydrodynamics at river confluences and provide better hydrodynamic results for water quality modelling in the future.     

南京长江第四大桥航行条件数值模拟研究

结合二维水流数学模型和船舶运动数学模型,研究了拟建南京长江第四大桥对通航水流条件的影响,分析了桥墩周围的水流条件变化,模拟了船队在建桥前后通过桥区河段的航迹线,得到了航行过程中的航行参数,综合分析认为南京四桥修建对通航水流条件影响很小,对船舶航行也无明显影响。     

Contamination with retinoic acid receptor agonists in two rivers in the Kinki region of Japan

This study was conducted to investigate the agonistic activity against human retinoic acid receptor (RAR) α in the Lake Biwa-Yodo River and the Ina River in the Kinki region of Japan. To accomplish this, a yeast two-hybrid assay was used to elucidate the spatial and temporal variations and potential sources of RARα agonist contamination in the river basins. RARα agonistic activity was commonly detected in the surface water samples collected along two rivers at different periods, with maximum all-trans retinoic acid (atRA) equivalents of 47.6 ng-atRA/L and 23.5 ng-atRA/L being observed in Lake Biwa-Yodo River and Ina River, respectively. The results indicated that RARα agonists are always present and widespread in the rivers. Comparative investigation of RARα and estrogen receptor α agonistic activities at 20 stations along each river revealed that the spatial variation pattern of RARα agonist contamination was entirely different from that of the estrogenic compound contamination. This suggests that the effluent from municipal wastewater treatment plants, a primary source of estrogenic compounds, seemed not to be the cause of RARα agonist contamination in the rivers. Fractionation using high performance liquid chromatography (HPLC) directed by the bioassay found two bioactive fractions from river water samples, suggesting the presence of at least two RARα agonists in the rivers. Although a trial conducted to identify RARα agonists in the major bioactive fraction was not completed as part of this study, comparison of retention times in HPLC analysis and quantification with liquid chromatography-mass spectrometry analysis revealed that the major causative contaminants responsible for the RARα agonistic activity were not RAs (natural RAR ligands) and 4-oxo-RAs, while 4-oxo-RAs were identified as the major RAR agonists in sewage in Beijing, China. These findings suggest that there are unknown RARα agonists with high activity in the rivers.     

邯郸市两河综合整治规划与环境保护探析

以邯郸市两河(滏阳河和沁河)综合整治规划为例,阐述了城市内河综合整治应考虑的诸要素,强调指出城市河流综合整治有别于传统意义上的河道整治,需多专业配合与协作。     

Mercury in the Mackenzie River delta and estuary: Concentrations and fluxes during open-water conditions

Estimates of mercury (Hg) loadings to the Arctic Ocean from circumpolar rivers have not considered biogeochemical changes that occur when river water is temporarily stored in large deltas (delta effect). There are also few data describing Hg changes across the freshwater-saltwater transition zone (FSTZ) of these rivers. We assessed temporal changes in unfiltered total mercury (THg) and methylmercury (MeHg) concentrations during open-water 2004 in the Mackenzie River upstream of the Mackenzie River delta, and in 6 floodplain lakes across an elevation gradient. These data were used to calculate Hg fluxes from the Mackenzie River and to evaluate a delta effect on Hg using an estimate of delta river water storage and a mixing analysis. Mean THg concentrations were highest in river water (9.17 ± 5.51 ng/L) and decreased up the lake elevation gradient. Mean MeHg concentrations were highest in lakes periodically connected to the river (0.213 ± 0.122 ng/L) and MeHg concentrations in elevated lakes showed a mid-summer peak. Results from the mixing analysis showed that the delta effect may be large enough to affect Hg loadings to the Arctic Ocean. THg concentrations exiting the delta (10.2 ng/L) were 16% lower than those entering (12.1 ng/L), whereas MeHg showed little change. We calculated 2.5-month (open-water) THg and MeHg fluxes from the Mackenzie River of 1208 and 8.4 kg. These fluxes are similar in magnitude to previous annual estimates in the arctic literature suggesting that previously published annual Hg fluxes from the Mackenzie River may be large underestimates. We also assessed changes in Mackenzie River water THg and MeHg concentrations as it crossed the FSTZ during an open-water cruise. THg decreased non-conservatively across the estuary from 3.8-0.6 ng/L, possibly due to mixing and particle settling. MeHg concentrations were variable and near detection. Our results show that the Mackenzie River estuary is a dynamic environment and may have important controls on Hg delivered to the Arctic Ocean.     

Hydrology and the ecological quality of Scottish river ecosystems

Hydrology is a primary control on the ecological quality of river systems, through its influence on flow, channel geomorphology, water quality and habitat availability. Scottish rivers are widely perceived to be of high ecological quality, with abundant flow volumes and high water quality. However, historical and current river flow regulations, and land use change have altered the physical and chemical characteristics of Scottish rivers, with adverse consequences for aquatic biota. Baseline hydrological, geomorphological and water quality conditions in Scottish rivers are thus summarised. The impacts of river regulation and land use change on the hydrology, geomorphology and water quality of Scottish rivers are then discussed. Consequences of these changes for aquatic habitat are examined, with particular reference to the economically significant salmonid species (Salmo salar and Salmo trutta). Policy and management issues relating to the future ecological quality of Scottish rivers are reviewed. These include the impacts of climate change on ecological quality, the calculation and implementation of ecologically acceptable flows, and river restoration and best management practices within integrated catchment planning.     

A decision support system for identifying the habitat quality and rehabilitation potential of urban rivers

Few habitat survey, classification or assessment methodologies have been developed specifically for urban or heavily engineered rivers, and yet these rivers need careful assessment if management options are to be considered and prioritised in an economically and environmentally effective way. This paper presents a refinement of a previously proposed urban river survey (URS), which is a modification of the Environment Agency's River Habitat Survey. It then describes indices and classifications that have been developed from URS data and that provide a link between the type of engineering applied to a stretch of urban river and its habitat characteristics. Finally, some simple decision trees and scenario‐modelling tools are presented that allow (i) newly surveyed urban stretches to be classified and (ii) some simple scenarios of channel management change to be assessed in order to prioritise management options for stretches of urban river across urban catchments.     

Assessment of the hydromorphological state of Carpathian rivers above and below reservoirs

The article presents the results of an assessment of the hydromorphological state of selected Carpathian rivers in sections above and below the reservoirs. An attempt has also been made to assess the impact of reservoirs on the hydromorphological conditions and quality of river habitats. The research was based on the River Habitat Survey (RHS) method. The synthetic indices Habitat Quality Assessment (HQA) and Habitat Modification Score (HMS) were calculated on the basis of the gathered data for each section studied; this allowed the hydromorphological qualities of the rivers to be assessed numerically. The reservoirs interrupt river continuum, and they alter different biotic and abiotic elements of natural environment. However, this study has shown that the operation of reservoirs does not always negatively impact the hydromorphological conditions of rivers that reflect their habitat quality. The influence of reservoirs on a river's hydromorphological state above and below a reservoir's location may be neutral, but it also can improve the habitat conditions of a river.