满拉工程设计中水文新技术的开发与应用

满拉水利枢纽所在流域环境恶劣，资料严重短缺，在设计中应用遥感技术解决冰川湖普查、重点冰川湖详查、全流域土壤侵蚀综合图绘制及龙马河与涅如藏布河分沙问题，提出了一套包括危险冰湖判别、溃决模式分析、溃决洪水定量计算的思路和方法，并在实施考察和溃湖洪水率定的基础上，计算了白湖溃决洪水和桑旺湖冰崩涌出洪水，其中白湖溃决洪水已被作为工程设防的依据，冰川湖动态监测系统采用海事卫星通信技术，不但解决了通信组网难等问题，也可在工程建成后实时监测上游较大冰湖的动态，一旦冰湖溃决可及时作出溃决洪水过程预报。以上几项新技术的开发与应用，解决了满拉工程本身的几个关键水文问题，也可供其它类似工程设计时参考。     

金沙江流域的河流泥沙输移特性

金沙江是长江上游河流泥沙的主要来源。通过对金沙江流域主要控制水文站径流泥沙资料的统计分析。该文论述了金沙江河流泥沙的来源和沿程分配、输水得的年内分配和年际变化、径流量和输水利一的关系以及泥沙形成的原因。为研究金沙江流域的水土流失和泥沙输移规律，合理地开发和利用其水土资源提供了科学依据。     

三峡水库和下游河道泥沙模拟与调控技术研究

三峡工程泥沙问题是贯穿三峡工程论证、设计、施工、运行中的关键技术问题之一,针对三峡水库蓄水运用以来出现的新情况、新问题和新需求,开展了三峡水库和下游河道泥沙模拟与调控技术研究,取得了如下主要成果:揭示了三峡水库泥沙絮凝规律、清水冲刷条件下推移质输沙及河床二次粗化机理、坝下游典型滩群演变与水库水沙过程调节的响应关系;提升了水库和坝下游河道泥沙数学模型技术,大幅提高了模拟精度;建立了三峡入库泥沙预测模式,提出了三峡入库新水沙系列;揭示了长江与洞庭湖、长江与鄱阳湖江湖分汇关系调整机理及变化趋势;研发了透水坝头和台阶式坝头两种新型航道整治结构技术;提出了三峡水库泥沙调控与多目标优化调度方案,优化了"蓄清排浑"运用方式,拓展了三峡工程综合效益,为三峡工程高效安全运行提供了技术支撑。     

长江流域水系划分与河流分级初步研究

将推荐的水系划分与河流分级Horton法相结合,通过合理选取最小河流(流域)单元、科学制作河流树状图表,初步研究了长江流域(不含太湖水系)的河流分级。研究结果显示:①推荐将长江水系划分为干流水系与雅砻江、岷江、嘉陵江、乌江、洞庭湖、汉江、鄱阳湖、太湖8个支流水系;② 581条河流基本特性资料的收集、整理与分析表明长江流域河流的河长与流域面积约为0.5次方关系,选取流域面积不小于2 000 km²或河长不小于100 km的河流为最小河流(流域)单元,确定长江流域(不含太湖水系)河流总数为374条;③以岷江水系为例,精心制作了长江流域各水系的河流树状图表,树状图显示了河流隶属关系、分级数、河长、流域面积等特性;④长江流域(不含太湖水系)最高河流分级数为6级。按河流统计:6级1条(0.3%),5级3条(0.8%),4级6条(1.6%),3级14条(3.7%),2级71条(19.0%),1级279条(74.6%);按水系统计:岷江、嘉陵江、鄱阳湖为5级,干流、雅砻江、洞庭湖、汉江为4级,乌江为3级。     

Rainfall-runoff simulation and flood forecasting for Huaihe Basin

The main purpose of this study was to forecast the inflow to Hongze Lake using the Xin＇anjiang rainfall-runoff model. The upper area of Hongze Lake in the Huaihe Basin was divided into 23 sub-basins, including the surface of Hongze Lake. The influence of reservoirs and gates on flood forecasting was considered in a practical and simple way. With a one-day time step, the linear and non-linear Muskingum method was used for channel flood routing, and the least-square regression model was used for real-time correction in flood forecasting. Representative historical data were collected for the model calibration. The hydrological model parameters for each sub-basin were calibrated individually, so the parameters of the Xin＇anjiang model were different for different sub-basins. This flood forecasting system was used in the real-time simulation of the large flood in 2005 and the results are satisfactory when compared with measured data from the flood.     

Modeling of sediment and heavy metal transport in Taihu Lake, China

With the current rapid economic growth, heavy metal pollution has become one of the key issues in the Taihu Lake. Although heavy metal pollution levels and distributions of the Taihu Lake have previously been described, an effective model to describe the transport process of heavy metals between the water column and sediment bed for this lake is not available. It is known that heavy metals in the water column can be related to the resuspension of sediment in the lake bed. In this study, we set up a coupled model of relating hydrodynamics, sediment and heavy metals based on Environmental Fluid Dynamics Code (EFDC), and applied it to Taihu Lake, China. For calibration and validation of the model, we employed two series of field sampling data taken all over Taihu Lake during April and July of 2009. The results show that the hydrodynamics simulations of the coupled model agree with the observations reasonably well and the sediment and heavy metal model shows similar variation trends during the simulation. Our results indicate that the model can be used for simulating the sediment and heavy metal transport process in the Taihu Lake and here we provide an effective tool for water quality management at small time scales.     

淮河中游河道与洪泽湖水沙交换程度分析

淮河中游河道与洪泽湖的水沙交换程度影响着河湖之间的内在关系,通过计算淮河与洪泽湖1975-2015年的水沙交换指数,利用多种统计检验交叉互补的方法,对河湖水量交换指数和泥沙交换指数进行了趋势变化、突变检验及周期性分析。结果表明：受不同年代治淮工程的影响,河湖水量交换指数整体而言呈不显著增大趋势,造成洪泽湖库容呈不显著增大趋势;入湖泥沙量大于出湖泥沙量,湖盆泥沙的淤积量逐年呈不显著增大趋势。洪泽湖库容及湖盆淤积在研究时期内呈稳定的波动状态,未发生较为显著的突变现象。淮河干流与洪泽湖的水沙交换程度存在多时间尺度的周期性特征,均以14a为第一主周期,河湖水沙交换程度处于相对稳定的状态。研究结果阐明了淮河中游河道与洪泽湖的水沙作用关系,可为河湖治理提供理论参考。     

松花江流域河流泥沙及其对人类活动的响应特征

对松花江流域主要水文站输沙量变化的分析表明：51年来,嫩江除1998年发生洪水外其余年份输沙量变化不大,第二松花江输沙量表现为明显的下降趋势,松花江干流输沙量也表现为下降趋势,而松花江整个流域在1979年之前为下降趋势,1979年之后为上升趋势。松花江干流区域和第二松花江为主要的泥沙来源区,分别占整个松花江流域输沙量的72.1%和16.2%。通过对单位降雨侵蚀力输沙量的分析,松花江流域输沙量负荷的变化与流域内重大历史事件、国家政策等人为活动的变化密切相关。＂大跃进＂时期嫩江流域输沙量负荷显著增大,三年自然灾害时期各区段输沙量负荷都出现峰值,＂文革＂时期各区段输沙量负荷起伏变化比较大,改革开放特别是家庭联产承包责任制实施以后,各区段输沙量负荷都呈现显著增长的趋势,90年代自然灾害频发使输沙量负荷持续出现峰值,直至1999年退耕还林后输沙量负荷才有所下降,但此后输沙量负荷又有不同程度的增长趋势。     

Influence of influent tributaries on water quality changes in Lake Mogan, Turkey

Lake Mogan, located in the steppes of central Anatolia, is a vital Turkish ecological system, in terms of its water resources, flora and fauna. The lake also is a unique recreational area for Ankara, the capital of Turkey. However, the lake is currently threatened by severe pollution, being under the risk of serious degradation because of (i) uncontrolled urbanization; (ii) point and non‐point source pollution; (iii) inefficient sewerage systems; (iv) sediment transportation and pollution via influent creeks to the lake; (v) uncontrolled soil erosion in its drainage basin; (vi) inappropriate flood control measures; and (vii) severe degradation of the natural wetlands within its drainage basin. This study evaluates the influence of its influent creeks on the water quality of Lake Mogan, mainly because the creeks are believed to be responsible for the major pollutant load reaching the lake, and because the extensive database documenting this situation has not previously been critically evaluated. Accordingly, this study reviews (i) change in the water quality of Lake Mogan between 1993 and 2002; (ii) the water quality classification of the major influent creeks feeding Lake Mogan; and (iii) the influence of the influent creeks on the water quality of the lake between 1993 and 2004.     

Combination of Runoff Simulation with Sediment Modeling in Rivers and Its Application in the Lower Yellow River

Abstract

Previous research on runoff show flow and sediment movement in rivers, and river bed variations are usually separated. This paper, from the point of view of the basin as a whole system, presents an integrated approach by combining runoff simulation with numerical model of sediment transport in rivers to simulate the whole processes of hydrological variables and flow-caused bed variations from the very upper part of the basin to the river mouth. To accomplish this purpose, BTOPMC, a rainfall-runoff model, and NUSTM-1D, a well-developed numerical model for sediment transport and river bed variations, are selected to form a combined model. The application of the proposed model to the lower Yellow River shows that it can properly simulate rainfall-caused runoff, the change of suspended sediment concentration along the river, and river bed variation.     

Characteristics of the delta formation resulting from sediment deposition in Lake Nasser, Egypt: Approach to tracing lake delta formation

A major problem encountered by managers of large reservoirs, such as Lake Nasser (located in the south of Egypt), is the continuous deposition of sediments, resulting in a bed-level increase, a decrease in lake capacity, and the creation of a new delta that might eventually hinder navigation. To investigate the sedimentation problem in Lake Nasser, a series of surveyed cross-sections were reviewed and samples of suspended sediment and bed material collected. These sets of data were analysed to investigate the progress of the delta formation, the change in its properties in all directions and the corresponding patterns of suspended and deposited sediment particles. Results showed that deposited sediments, characterized by a variable pattern of particle composition, are building up at the lake entrance. Although the expansion of the delta is multidirectional, its accelerated advance towards the High Aswan Dam would depend on the frequent occurrence of high floods following extended drought periods. Based on the calculated deposited sediment volume in Lake Nasser during the period 1964–1998, the lifetime of the dead storage zone allocated for sediment deposition (31 × 10⁹ m³) is estimated at a minimum of 310 years.     

一维水沙数学模型江湖联算初探

 为研究三峡建库后复杂多变的江湖关系，建立了一维恒定流全沙数学模模型，对江湖主要控制站的年径流量、三口分流量、三口分流过程、三口分沙量均进行了计算与分析。结果表明，该数学模型计算的长江及洞庭湖主要水沙情况与实测情况相近，可用于江湖关系的定量分析。     

鄱阳湖流域气候变化和人类活动对入湖水沙的影响

近些年鄱阳湖湖区季节性干枯问题频繁出现,有必要对鄱阳湖入湖水沙变化进行进一步研究。利用鄱阳湖流域"五河"基本水文站1961～2016年实测的水沙及流域降雨量资料,通过线性趋势、双累积曲线、经验统计法和统计系列对比法研究鄱阳湖入湖水沙演变过程及影响因素。结果表明:鄱阳湖流域降雨量、侵蚀性降雨量、降雨侵蚀力年际变化均呈不显著的上升趋势(P0.05)。入湖径流量年际变化趋势不显著,而入湖输沙量呈极显著的下降趋势(P0.01),且存在1985年和2000年两个突变点。影响入湖径流量和输沙量的关键降雨指标为年降雨量和降雨侵蚀力。以1961～1984年为基准期,1985～1999年经验统计法和系列对比法计算的水利水保工程减沙效应分别为41.8%和33.4%,在2000～2016年分别为70.6%和66.8%,水库拦沙是入湖输沙量减少的主要原因。     

50年来灞河流域水沙变化特征分析

根据灞河流域水沙特点,选取反映灞河流域水沙变化趋势的马渡王水文站,利用灞河流域50年的实测年径流量和年输沙量资料,采用Mann-Kendall非参数统计检验法、小波分析法、双累积曲线法,结合流域降雨量分析了灞河流域水沙年际变化特点及突变的年份。结果表明:灞河流域水沙年内分配极不均匀,水沙总体下降趋势明显;水沙序列具有多时间尺度特征,但变化尺度并不一致;径流量和输沙量分别在1989年和1981年发生了突变,但突变时间具有差异性,且输沙量的敏感性更强;进一步分析表明,降雨量的波动是径流量年际变化的主要影响因素,而输沙量的减少则主要受到径流量和人类活动的综合影响。     

Evaluation of dike-type causeway impacts on the flow and salinity regimes in Urmia Lake,Iran

Urmia Lake, located in a closed basin in north-west Iran, is the largest lake (5000–6000 km²) in the Middle East. It is very saline with total dissolved salts reaching 200 g/l compared with a normal seawater salinity of about 35 g/l. The construction of a causeway, which was initiated in 1979 but then abandoned until the early 2000s, is near completion and will provide road access between the western and eastern provinces. The causeway has an opening 1.25 km long and divides Urmia Lake into a northern and southern basin and restricts water exchange. The flow and salinity regimes are affected by the presence of this new causeway, and there are concerns over the well being of the Artemia population. This study investigates the effects of the construction of the causeway on flow and salinity regimes, considers remedial actions, and examines the effects of climatic variability on salinity and flow. Flow and salinity regimes were numerically simulated by using a commercially available two and three-dimensional (2D and 3D) MIKE model. The validity of the numerical model was assessed through sensitivity analysis of the model and comparing the simulated results against field measurements; the 3D model provided the higher correlation between simulated and actual data. Wind input was the main climatic and hydrologic factor influencing flow regime while river discharge, evaporation and rainfall were the key parameters affecting salinity distribution in the lake models. The 3D model was subsequently used to predict lake conditions in typical dry, wet and normal climates, to examine the environmental impacts from the new causeway, and to evaluate possible improvements that some remedial measures may provide.     

Assessment of heavy metal contamination in coastal lake sediments associated with urbanization: Southern Kerala,India

The study of the spatiotemporal variation of heavy metals in lake sediments is of great importance because heavy metals can result in toxic effects on aquatic biota through bioaccumulation. This study was undertaken to evaluate the degree of heavy metal contamination in the lacustrine sediments and the corresponding environmental deterioration in a tropical, urban, coastal lake (Akkulam–Veli), located in Kerala, India. The spatiotemporal variations of the cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni) and zinc (Zn) concentrations in the lake sediments, as well as various indices of anthropogenic contamination, including Contamination Factor (CF), Pollution Load Index and Geoaccumulation Index (Igeo), were used to assess the degree of contamination. This study indicated contamination of the lake sediments with Cu, Pb and Zn. Urban domestic sewage and land run‐off are the major drivers of the heavy metal loads to the lake. During the pre‐monsoon, sediment contamination occurs in the upstream portion of Akkulam Lake because of a high clay content in the sediments. During the monsoon period, Akkulam Lake and the upstream portion of Veli Lake exhibit sediment contamination owing to high silt content. Domestic sewage is the main source of copper and zinc to the lake. Sewage bypass into the drains in the lake basin is largely responsible for the copper and zinc sediment contamination. High traffic levels and wastewater discharges from service stations/workshops are the main cause of the Pb loads entering the lake. Rubber particles of vehicle tires contain zinc and copper pigments that can accumulate on the surface of busy streets, entering the drains during rainfall events. Based on these study results, the accumulation of copper, zinc and lead in lake sediment can be controlled to a great extent by restricting the above‐noted activities. As the sediment content of lead, zinc and copper is confined to the clay fraction during the non‐rainy season and to the silt fraction during other seasons, lake restoration work should largely incorporate treating the clay and silt fractions, respectively, during both the non‐rainy season and rainy season.     

River, reservoir and lake sediment contamination by heavy metals downstream from urban areas of Switzerland

This paper quantifies sediment contamination by heavy metals in four reservoirs and one lake located downstream from major urban areas in Switzerland. The waterbodies include the Wettingen Reservoir (located on the Limmat River downstream from Zürich), the Klingnau Reservoir (on the lower Aare River), the Wohlen Reservoir (downstream from Berne), the Verbois Reservoir (downstream from Geneva) and Vidy Bay (Lake Geneva, city of Lausanne). For all sediment cores and contaminants, a trend is observed from high contaminant values in the lower part of the cores, decreasing to lower concentrations in the upper part of the cores. However, for each site and each element, specific features are recognized. Applying the criteria of the Swiss ordinance on soil protection, all sediment cores must be classified as contaminated by one or more contaminants and at variable levels. From these data, it is concluded that: reservoirs and lakes located downstream from major urban centres in Switzerland have accumulated significant volumes of contaminated sediments in the past, representing the largest, but not the most intensely, contaminated sites on a national scale; the main environmental risk is remobilization of the contaminants and their return to the food chain, particularly by infiltration into the groundwater; and although the processes of remobilization are identified, the conditions of occurrence and the amplitude of the processes are still poorly known. Different options of reservoir and lake sediment management also are discussed and further research topics defined.     

苏只水电站坝前支沟泥沙调查分析及枢纽防沙措施

苏只水电站坝前400～600m范围内有2条较大的支沟——甘都沟和苏只沟，支沟距坝较近，其泥沙对电站的威胁较大，苏只水电站的主要泥沙问题是研究解决坝前2条支沟的泥沙问题。通过对支沟水沙调查分析计算，确定了支沟入库水沙特性。通过模型试验和入库水沙分析提出的水库泥沙调度运行方式及防排沙措施，基本解决了电站的主要泥沙问题。     

窟野河水文特性分析

根据黄河中游较大支流窟野河流域各水文站历年水文资料统计,通过对流域概况、降水、径流、泥沙以及洪水特性的分析,得出主要结论:窟野河降水量、径流量、输沙量年际变化大,年内分配不均,窟野河暴雨洪水特点是该流域发生大洪水机遇较多,洪水过程陡涨陡落,历时短,含沙量大,泥沙颗粒组。     

Impacts of wind waves on sediment transport in a large,shallow lake

Lake Okeechobee is a large, shallow subtropical lake, located in south Florida. Over the last several decades, Lake Okeechobee has experienced accelerated eutrophication due to excessive phosphorus loads from agricultural run‐off. Recycling of phosphorus from bottom sediments through resuspension is critical to addressing eutrophication of the lake and for water quality management. The present study investigates the impacts of wind waves on sediment transport in Lake Okeechobee, using measured data and the Lake Okeechobee Environmental Model (LOEM). The LOEM was fully calibrated and verified with more than 10 years of measured data in previous studies. Analysis of the measured data indicates significant wave height (SWH) and suspended sediment concentration are closely correlated to the wind speed in the lake. The nonlinear interaction of high‐frequency wind waves with relatively low‐frequency currents in the boundary layer plays a key role in sediment deposition/resuspension. Without considering the effects of wind waves, the bottom shear stress can be greatly underestimated. The spatial variations of key variables for sediment modelling, including SWH, water depth, orbital velocity, current velocity, bottom shear stress and sediment concentration, are discussed. In general, the near‐bottom wave velocity (and the associated bottom shear stress) is greater than or the same order of magnitude as the near‐bed current velocity (and the associated bottom shear stress) in this shallow water system. Although the sediment zones of Lake Okeechobee were described in previous studies, few published papers discussed its formation mechanisms. The findings of the present study include that the multiyear averaged bottom shear stress with wind‐wave effect plays a key role in forming the spatial patterns of the sediment zones. The study results are currently being used in lake management and in developing strategies for reducing phosphorus in the lake.