Response of the distributary channel of the Huanghe River estuary to water and sediment discharge regulation in 2007

The water and sediment discharge regulation （WSDR） project, which has been performed since 2002 before flood season every year, is of great significance to the river management in China. Until 2007, six experiments have been fulfilled to evaluate the effect of the project on the natural environment. To fill the gap of investigations, a study on flood and suspended sediment transportation and channel changing along the distributary channel of the Huanghe （Yellow） River was conducted during the WSDR project period in 2007. The lower channel was scoured rapidly and the channel became unobstructed gradually several days after the flood peak water was discharged from the Xiaolangdi Reservoir. Within four days after the flood peak at 3 000 m3/s entered the distributary, the channel in the river mouth area was eroded quickly. Both the mean values of area and depth of the main channel were tripled, and the maximum flood carrying capacity increased to 5 500 m3/s or more. Then, the river channel was silted anew in a very short time after completion of the WSDR. Favored by the WSDR project, the fiver status in April 2008 became better than that of the year before. The adjustment ranges of main channel parameters were about 30%, 10%, and 10% at sections C2, Q4, and Q7, respectively. The process of rapid erosion-deposition was more active 15 km away in the channel from the fiver mouth due to the marine influence. It is reasonable for discharging sediment at concentration peak from Xiaolangdi Reservoir at the end of the flood peak. As a result, the sediment peak reached the river mouth about two days later than that of the water current. In addition, the WSDR project has improved the development of the estuarine wetland. Wetland vegetation planted along the river banks restrained the water flow as a strainer and improved the main channel stability. It is suggested to draw water at mean rate of 150 m3/s from the Huanghe River during flood periods, because at the rate the water in the wetland would be stored and replenished in balance. Moreover, we believe that cropland on the river shoal of the lower Huanghe River should be replaced by wetland. These activities should achieve the Huanghe River management strategy of ＂To concentrate flow to scour sediment, stabilize the main channel, and regulate water and sediment＂.

Trace Metal Contamination of Water in the Lubumbashi River Basin, Kafubu, Kimilolo and Kinkalabwamba Rivers in Lubumbashi City, Democratic Republic of Congo

Concentrations of fifteen trace metals including Aluminum （Al）, Vanadium （V）, Chromium （Cr）, Manganese （Mn）, Iron （Fe）, Strontium （Sr）, Molybdenum （Mo）, Silver （Ag）, Cadmium （Cd）, Tin （Sn）, Caesium （Cs）, Barium （Ba）, Lead （Pb）, Bismuth （Bi） and Uranium （U） were investigated in water samples collected from sixteen sampling locations in the Lubumbashi river basin and five locations in Kafubu, Kimilolo and Kinkalabwamba rivers during February, March and April 2016. Chemical analyses of the samples were carried out using ICP-MS （Inductively Coupled Plasma-Mass Spectrometer）. Water pH was determined using a pH-meter and pH values ranged from 4.2 to 7.8. The highest mean trace metal levels of water were 5,515.816 ）μg·L^-1, 166.925μg·L^-1, 3.898μg·L^-1 and 1.879μg·L^-1 for Al, Ba, Cr and U, respectively in Kashobwe river, 2,419.522 μg·L^-1 and 17.994 μg·L^-1 for Fe and Cd, respectively in Kafubu river at its confluence with Lubumbashi rivers, 1,408.136μg·L^-1 for Mn in Kafubu river 1.36 kilometer downward its confluence with Naviundu river, 222.406 μg·L^-1 and 0.092 μg·L^-1 for Sr and Cs, respectively in Kamalondo river 60 meters from the GCM-Lubumbashi （General of Quarries and Mines-Lubumbashi） smelter, 140.294μg·L^-1, 12.063 μg·L^-1 and 0.008μg·L^-1 for Pb, V and Bi, respectively in Munua river, 3.544 μg·L^-1 for Ag in Kabulameshi river, 1.49 μg·L^-1 for Mo in Kafubu river and 0.081μg·L^-1 for Sn in Tshondo river. The mean concentrations of Al, Cd, Fe, Mn and Pb in water of many rivers and the channel exceeded the maximum admissible limits of the WHO （World Health Organization）, USEPA （United States Environmental Protection Agency） and EU （European Union） drinking-water standards. Trace metal contamination of water of the studied rivers, channel and springs might be partially attributed to natural processes, unplanned urbanization, poor waste management and mostly to abandoned and ongoing mining and ore processing activities in Lubumbashi city.

Trace Metal Contamination of Water in Naviundu River Basin, Luano and Ruashi Rivers and Luwowoshi Spring in Lubumbashi City, Democratic Republic of Congo

Aluminum （AI）, Vanadium （V）, Chromium （Cr）, Manganese （Mn）, Iron （Fe）, Strontium （Sr）, Molybdenum （Mo）, Silver （Ag）, Cadmium （Cd）, Tin （Sn）, Caesium （Cs）, Barium （Ba）, Lead （Pb）, Bismuth （Bi） and Uranium （U） concentrations were investigated in water samples from fifteen sampling locations in Naviundu river basin, Luano and Ruashi rivers and Luwowoshi spring in Lubumbashi city during February, March and April 2016. Chemical analyses of the samples were carried out using Inductively Coupled Plasma-Mass Spectrometer. Water pH was determined using a pH-meter and mean pH values ranged from 4.2 to 5.8. The highest mean levels of Al （5,961.954 μg·L^-1）, Pb （472.287 μg·L^-1）, V （21.014 μg·L^-1）, Cr （8.185μg·L^-1）, U （4.163μg·L^-1） and Bi （0.012 μg·L^-1） were recorded in Chemaf （Chemicals of Africa） hydrometallurgical plant effluent, those of Mn （29,714.593 μg·L^-1）, Sr （374.377μg·L^-1）, Cd （11.358μg·L^-1） and Cs （0.107μg·L^-1） in Naviundu river at Cimenkat （Katanga＇s Cement Factory） exit, those of Fe （14,258.9 μg·L^-1） and Ba （307.641μg·L^-1） in Luano river and those of Ag （2.669 μg·L^-1）, Mo （0.559 μg·L^-1） and Sn （0.325 μg·L^-1） were respectively noted in Foire channel, Naviundu river under bridge on Kasenga road and Kalulako river. The concentrations of Cd in Naviundu river at Cimenkat exit （11.358 μg·L^-1）, Chemaf bydrometallurgical plant effluent （9.697μg·L^-1）, Naviundu river under bridge on De Plaines Avenue （6.95 μg·L^-1） and Kalulako river （3.229 μg·L^-1）, Pb concentrations in Chemaf hydrometallurgical plant effluent （472.287 μg·L^-1） as well as the AI, Fe and Mn concentrations recorded in most waters in this study exceeded the WHO （World Health Organization） maximum permissible limits for drinking water. The metal contamination of waters of the studied rivers, channel and spring might be partially attributed to natural processes, unplanned urbanization and poor waste management, and mostly to abandoned and ongoing mining and ore processing activities in Lubumbashi city.

Water level updating model for flow calculation of river networks

Complex water movement and insufficient observation stations are the unfavorable factors in improving the accuracy of flow calculation of river networks. A water level updating model for river networks was set up based on a three-step method at key nodes, and model correction values were collected from gauge stations. To improve the accuracy of water level and discharge forecasts for the entire network, the discrete coefficients of the Saint-Venant equations for river sections were regarded as the media carrying the correction values from observation locations to other cross-sections of the river network system. To examine the applicability, the updating model was applied to flow calculation of an ideal river network and the Chengtong section of the Yangtze River. Comparison of the forecast results with the observed data demonstrates that this updating model can improve the forecast accuracy in both ideal and real river networks.

Relationship between adjustment of low water level and utilization of water depth in Shashi Reach in middle Yangtze River

Hydrological,sediment,and bathymetric data of the Shashi Reach in the middle Yangtze River for the period of 1975-2018 were collected,and the characteristics of low water level changes and their impacts on utilization of water depth for navigation were investigated.The results showed that,during the study period,the Shashi Reach riverbed was significantly scoured and incised,with cross-sectional profiles showing overall narrowing and deepening.This indicated a strong potential to improve the water depth of the channel.The analysis of the temporal variation of in-channel topographical features showed that the Taipingkou diara underwent siltation and erosion,with its head gradually scoured and relocated downstream after 2008,and the Sanbatan diara continued to shrink and migrate leftwards.Low water levels with the same flow rate over the study period decreased.For instance,from 2003 to 2020,the water level at the Shashi hydrological station decreased to 1.37 m with a flow rate of 6000 m^(3)/s.Furthermore,the designed minimum navigable water level of the Shashi Reach was approximately 2.11m lower than the recommended level.In terms of utilization of the channel water depth,continuous scouring of the river channel is expected to result in a reduction in discharge at the Taipingkou mouth,which will improve the water depth conditions of the channel during the dry season in the Shashi Reach.With several channel regulation projects,the 3.5-m depth of the Shashi Reach would basically be unobstructed.This promotes utilization of the shipping route from the Taipingkou south branch to the Sanbatan north branch as the main navigation channel during the dry season.Considering the factors of current water depth and the clear width limitation of the navigation hole at the Jingzhou Yangtze River Bridge,this route can still be favored as the main navigation channel with a 4.5-m depth during the dry season.

黄河下游花园口以上河段滞沙能力分析

黄河下游河床调整主要取决于来水来沙和河床边界条件,河床调整沿程不均衡特征明显,花园口以上河段床演变对水沙条件的变化响应尤为突出,泥沙冲淤调整幅度最大。基于河道冲淤及水沙演进特性、滞沙可行性、河槽几何特性等分析,提出了花园口以上河段可作为泥沙天然反调节“库”概念,结合黄河下游实测洪水资料,采用水力计算方法,计算了花园口以上河段的河槽排洪能力及不同河槽规模条件下河槽允许滞沙量,提出了反调“库”滞沙能力,可为小浪底水库排沙指标的确定提供依据,对维持小浪底水库有效库容、弥补后续清水河床沙源不足、改善黄河下游河槽冲淤不均衡现象具有重要意义。

基于流域储水量精细化模拟的干旱指数构建及应用

为构建一种客观反映河道槽蓄量、水库蓄水量和土壤含水量联合亏缺的干旱指数,以秦淮河流域为研究区,基于500 m×500 m分辨率的VIC-FLASH模型,通过精细化模拟流域河道、水库和土壤中存储水量的变化过程,构建了标准化流域储水指数(SWSI),并应用SWSI对1980—2019年秦淮河流域历史干旱事件和干旱特征进行分析,验证了其可靠性和应用优势。结果表明:高分辨率VIC-FLASH模型可以较好地模拟流域储水量时空分布,流量过程模拟结果平均相对误差为10.6%,流域内6座水库实测与模拟蓄水量相关系数为0.53~0.86;SWSI可以准确识别干旱事件和反映区域干旱严重程度,干旱烈度与实际受旱面积的相关系数为0.88;1980—2019年逐日SWSI与标准化径流指数和土壤含水量距平指数的相关系数分别为0.89和0.98;SWSI不仅可以定量反映流域储水量的亏缺状态,而且可以更加客观地反映旱情时空演变过程。

引江补汉工程丹江口下游近坝段枯水期通航水位恢复试验研究

引江补汉工程补水口位于丹江口大坝下游安乐河出口约5 km处,且补水量与调水量基本一致,工程对航道的影响主要体现在减水段,为恢复枯水期通航水位需要开展航道综合治理。利用河工模型试验论证了综合治理方案的效果,并对方案进行了优化及进一步论证。结果表明,减水-补水212 m 3/s方案尾门水位分别为86.47、85.90 m条件下,引航道口—黄家港段水位下降,黄家港以下水位保持不变,其中引航道口水位下降幅度最大,分别下降0.08、0.19 m;综合治理方案1实施后引航道口水位下降均为0.02 m,减水段的水位仍未恢复至调水前的水平,主因是从安乐河口补水的水流并未能进入到左侧主航道内;基于试验研究结果,建议对综合治理方案进行优化,在沧浪洲出水口下沿布置2道护底带;通过试验论证了护底带的4个高程,建议护底带高程为85.5 m,并对护底带高程进一步细化论证;优化后的方案可使引航道口至黄家港段的水位略超过调水前的水平,其中引航道口处最大水位抬高0.06 m。

黄河下游灌区引黄涵闸引水能力变化原因分析

黄河下游引黄涵闸受河床下切、河势变化等因素共同影响,引水条件与设计情况相比发生了变化,造成部分河段涵闸引水困难,影响农业适时灌溉和生产。为给应对引黄涵闸引水能力下降问题提供参考,基于黄河下游2000—2016年引黄涵闸引水水位和河道断面实测数据,分析引黄涵闸引水水位变化、河槽冲刷、引黄渠道淤积变化等因素对引黄涵闸引水能力产生的影响。结果表明:1)2016年黄河来水300~900 m^(3)/s时,黄河下游引黄涵闸实际引水能力仅为设计引水能力的13.63%~39.43%,引黄涵闸引水能力明显下降;2)相较2000年,2016年的引黄涵闸设计值对应黄河流量的水位,高村以上河段下降了2.95~3.35 m,高村以下河段下降了1.55~2.95 m;3)从河段河床平均冲刷厚度看,花园口—夹河滩、夹河滩—高村、高村—孙口、孙口—艾山、艾山—泺口、泺口—利津河段的冲刷厚度分别为3.88、3.06、1.84、1.88、1.88、2.02 m,河槽连续冲刷导致同流量水位明显降低,严重影响河南和山东段引黄涵闸正常引水;4)涵闸前后引、输水渠道淤积会导致引黄涵闸引水能力降低。

长江南京以下深水航道野外观测数据服务平台建设

为提升深水航道数据资源的采集、融合、分析及应用能力,在南京长江深水航道水沙环境与工程安全交通运输行业野外科学观测研究基地进行长江深水航道野外观测数据服务平台建设。服务平台采用B∕S架构,通过物联网、分布式建构等技术手段结合常用网络传输协议连接各数据集群,实现多源异构历史资料的整合与治理、实时监测数据的接入和第三方数据的聚合,开发了数据门户、水运一张图、工程专题、监测大屏、水位预测等专题应用。平台建设实现了以深水航道为主题的数据聚合与共享。

干旱地区河槽暗蓄雨洪资源化利用模拟

目的 研究利用雨洪资源解决干旱地区用水短缺问题,提出利用河槽暗蓄收集雨洪最佳工程方案,为该类工程的设计提供参考。方法 应用Visual Modflow软件模拟研究辽西喀左地区内第二牤牛河流域中不同调蓄方案和拦蓄入渗方案对河槽暗蓄雨洪资源化的影响。结果 通过不同调蓄方案的对比,采用可调控悬挂截渗坝代替现有截渗坝时,雨洪资源利用率可提高至20.3%;通过不同拦蓄入渗方案的对比,“不清河床+坑塘+拦水堰”方案的雨洪资源入渗量为天然条件下雨洪资源入渗量100倍以上。结论 河槽暗蓄雨洪资源化工程最佳的拦蓄入渗和调蓄组合方案为在“不清河床+坑塘+拦水堰”的情况下采用可调控悬挂截渗坝,可显著提高雨洪资源利用率。

巴基斯坦卡洛特水电站取水防沙试验研究

多沙河流上水电站取水发电,泥沙问题是需要解决的关键问题。本文通过物理模型试验,研究了巴基斯坦卡洛特水电站泥沙淤积发展规律。结果表明:通过“分级相机拉沙”排沙优化调度运行方式和“双重弯道分沙取水”枢纽布局,卡洛特水电站的淤积平衡年限延长至20年,坝上游8.15 km河段泥沙累积淤积量为4782.3万m^(3),平均淤厚27.4 m,最大淤厚51.7 m,兴利库容保留率78.56%;蓄水期,过机水流含沙量降低92.1%,汛前和汛后过机水流含沙量降低33.7%,全年通过电厂机组的水流含沙量不超过1.2 kg/m^(3),过机泥沙粒径原型值最大为0.02 mm,基本无粗沙过机问题。卡洛特水电站排沙调度方式和枢纽布局为解决高原地区多沙河流水电站泥沙问题提供了解决思路。

现行黄河口分汊河道的分流特征及其影响机制

自2013年黄河尾闾河道出汊形成双槽入海的河口汊道,控制了河口流量的分配,但其分流特征及其影响机制尚不清楚。本文基于Delft3D构建了黄河口汊道的水动力三维数值模型,模拟了不同工况下河口汊道的分流特征,揭示了其影响机制。结果表明:河口汊道的分流不对称性随流量的增加而减小,流量增加加大了东汊与北汊河道的水位梯度差,使得从东汊河道的流量增量较北汊河道大,河流流量的分配更加均匀。潮汐作用增强了河口汊道的流量不对称性,而随着径流量的增加,潮汐的增强作用逐渐减弱。这主要由于在半日潮的作用下,东汊和北汊河道水位梯度的差异,形成河口潮汐的“东阻北促”效应,增强了河口汊道的分流不对称性。

持续冲刷期内黄河下游河床演变特点分析

基于2006年10月至2018年11月黄河下游12个典型断面观测数据,通过分析断面主槽平滩形态特征参数变化率及深泓线和主槽中心线的摆动强度,探讨了持续冲刷期内下游河床的调整变化过程及特点。结果表明:黄河下游断面形态调整表现出既有横向展宽又有冲深下切或淤高态势;河床平面摆动促进了断面主槽形态调整,河相系数变化率与深泓线和主槽中心线摆动强度均成正相关关系;来水来沙条件是主槽形态改变的主要驱动力,且可引起局部河段深泓线摆动强度增大。通过调整小浪底水库的运行模式及布设控导工程可进一步塑造并维持稳定的黄河下游中水河槽。

长江流域取水许可知识图谱问答系统

随着水资源取水许可领域管理要求的不断提高,传统水资源取水许可信息管理系统难以满足复杂的信息检索需求,制约了水资源精细化管理水平的提升。为了打破系统间信息孤岛,提升取水许可信息检索效率,建立了长江流域取水许可知识图谱,基于大规模预训练语言模型提出了包含实体提及识别、实体链接、关系匹配等功能的知识图谱问答流水线方法,结合取水许可领域数据特点采用BM25算法进行候选实体排序,构建了长江流域取水许可知识图谱问答系统,并基于BS架构开发了Web客户端。实验表明:该系统在测试集上达到了90.37%的准确率,可支撑长江流域取水许可领域检索需求。

河流分类分级分段及河流形态学研究进展

河流分类、河流分级及干流河道分段合称为河流三分(分类·分级·分段);基于河流三要素(流域-水系-干流河道)和河流三分-河流形态学-河流学体系,开展了河流三分理论研究及实践应用、河流形态学再构建以及河流形态定性特性与定量因子指标辨识。主要成果结论包括:①优化了独立与非独立河流分类、河流分级Horton法改进、河流5区分段等方法,完善了河流界定拓展、河流平等与分级、干流河道“层次分段”等新理论,总结了世界大江大河及长江河流三分实践应用;②河流形态学研究河流现状及恒常形态,包括以河流三分为基石的河流三要素特性研究和以干流河道平面-剖面-断面形态为核心的河谷-河床-河道形态研究;③定性辨识了河流形态15项殊相特性与共相原则(包括复合流域水系、复杂干流河道等形态特性,干流河道优先、河流湖泊统一、干流河道唯一、侵蚀基面统一等新增原则);④定量辨识了河流形态4类因子指标,双指标3种相关关系(并行-从属-或然)与3类组合模式(物理-化学-生物)以及三因子4类及9种相关模式(均衡线型-瓶颈线型-三角形-金字塔-均分圆-同心圆-同切圆-交叉圆-三角圆)。倡导“河流学-长江学-水科学”学科范式,积极践行“治河·治江·治水”理念。

永定河门头沟段河道生态需水特征研究

为提高永定河门头沟段的整体生态健康状况,保障河道生态需水量,应对气候变化和人类活动对河流生态系统的影响,研究分析了该区的水文气象要素演变特征及河道生态需水的时间序列动态。根据永定河门头沟段的生态保护目标,采用环境功能设定法整合计算了包括生态基流、水生生物需水、输沙需水、自净需水和水面蒸发需水5项河道生态需水量。并通过定量分析气候变化和人类活动对径流的影响来确定河道生态需水的影响因素。结果显示,1980—2020年研究区域年平均气温呈显著上升趋势,年降水量有所增加但并不显著;1980—2020年区域河道生态需水量呈显著减少趋势,其中水生生物需水量最大。人类活动是影响区域生态需水量的最主要因素,其通过影响径流量进而影响河道生态需水量。研究结果可为未来永定河门头沟段的水量调配、水资源管理、河道生态需水量预测提供理论参考。

黄河现行流路与启用刁口流路不同情景下调水调沙期间入海水沙扩散特征与影响因素

《黄河流域综合规划(2012—2030年)》中指出,规划期内仍主要利用清水沟流路行河,保持流路相对稳定,清水沟流路使用结束后,优先启用刁口备用流路。为探究黄河启用刁口流路后入海水沙扩散特征及其与现行流路的差异,本研究选取黄河水沙入海的主要时期——调水调沙期,通过FVCOM三维数值模式,模拟研究了黄河调水调沙期间经两条流路入海情况下的盐度、悬沙浓度及河口动力特征,对比发现(1)两条流路沿岸流系总体变化趋势一致,入海径流受地转偏向力影响整体向东偏转,局部流场存在差异,刁口流路入海时无明显环流;(2)两种流路下羽流和悬沙的扩散特征对调水调沙不同阶段的水沙变化存在一致性的响应;然而,受河口地形和岸线的影响,刁口流路情景下羽流和悬沙的扩散范围显著大于现行流路;(3)伴随着流路变化,三角洲不同区域的演化特征将产生快速响应:刁口流路启用后,现行河口三角洲将进入蚀退期,刁口三角洲叶瓣进入快速造陆期。此外,模型结果显示,由于刁口外较浅的水深和平缓的地貌特征,相同条件下刁口流路情景下三角洲的造陆速率在短期内可能高于现行流路。

黄河下游高村-孙口段冲淤变化及影响因素定量分析

为探究黄河过渡段河道滩槽演变规律,采用实测水沙和大断面数据,分析近年来高孙段河床冲淤、水沙条件和河床形态的演变,以年和汛期为时间尺度,用灰色关联度分析河槽冲淤量与水沙条件及河床形态的关联程度。结果表明,近年来高孙段以冲刷为主,汛期是年内输沙的主要时期;高村断面来沙系数可以分为波动减小(2002~2017年)和快速增加(2018~2019年)两大阶段,而河床形态中水力半径和宽深比变化趋势完全相反,糙率存在增大趋势;高村断面的水沙条件及河床形态与高孙段河道冲淤具有较高的关联程度,河床形态比水沙条件具有更高的相关性。

黄河下游游荡性河段心滩形态特征与水沙过程响应关系

黄河下游游荡性河段素以调整速度快与幅度大著称,河道心滩复杂多变,探究心滩形态特征与水沙过程之间的响应关系对于解析下游游荡性河段的河床演变机制具有重要的意义。围绕黄河下游铁谢至高村游荡性河段的心滩面积与数量等形态特征指标,结合下游水沙及冲淤特性,采用遥感影像和数值模拟相结合的研究方法厘清游荡性河段水沙过程与心滩面积及数量之间的响应关系,揭示水沙变化对心滩形态特征的影响机制。结果表明:自小浪底水库运用以来,下游河道发生剧烈冲刷,游荡性河段累计冲刷量15.37亿m^(3),占下游累计冲刷量的68%;在小浪底水库运用以前,游荡性河段的心滩面积与数量年际变化剧烈,存在着明显的增长与降低变化过程,而小浪底水库运用以后,该河段的心滩面积与数量呈现先减小后增大再减小的变化趋势;随着4 a滑动汛期平均流量和4 a滑动汛期平均来沙系数的增加,游荡性河段的心滩面积及数量分别呈现出减小和增大的变化趋势。数值模拟方法不仅可以较好地再现心滩发育及演变过程,还可以定性地表征特定水动力学因素对心滩形态特征塑造的影响,为阐明游荡性河段的心滩演变理论提供了一种新的研究方法。研究成果不仅有助于阐明河流平面形态的调整过程,还可为今后河道整治工程的布局提供理论支撑。