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Influence of the impounding process of the Three Gorges Reservoir up to water level 172.5m on water eutrophication in the Xiangxi Bay

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Science china(Technological Sciences) 2010年第4期53卷 1114-1125页

作者： YANG ZhengJian1,LIU DeFu1,JI DaoBin1,2.& XIAO ShangBin1,3 1 college of Civil & Hydroelectric engineering,{2. Three Gorges university,Yichang 443002.{2. 2.School of water resources & hydropower engineering,wuhan university,wuhan {12.,{2. 3 Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,{2. 1. college of Civil & Hydroelectric engineering China Three Gorges University Yichang 443002 China2. School of Water Resources & Hydropower Engineering Wuhan University Wuhan 430072 China3. Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China

The water level of the Three Gorges Reservoir(TGR) rose to 172.5 m in two stages from September to November,*** hydrodynamic parameters and water quality parameters(*** velocity,temperature,turbidity and nutrient content) had been continuously monitored to reveal the influence of the impounding process of the TGR on the water eutrophication in the Xiangxi Bay(XXB).The maximal daily rise of the water level of the TGR was about 2.38 *** water exchange between the mainstream(the Changjiang River) and the XXB of the TGR was enhanced by density current,and its main characteristics were a density-stratified flow in different *** water exchange reduced the differences of the water quality parameters(for example,temperature,turbidity,nutrient level,pH,etc.) between the mainstream and the XXB during the impounding ***,the water stability index in the mainstream remained small but it was lowered in the *** main causes included the dilution by water of lower concentration of the chlorophyll a(Chl.a) entering from the mainstream,the decline of the water stability,and the increase of suspended silt,which induced the Chl.a to decrease in the XXB during the impounding *** grade of the water eutrophication changed from middle eutrophic level to mesotrophic state in the ***,as available nutrients were imported into the XXB from the mainstream during the impounding process the risk of water eutrophication increases in the XXB in the future.

关键词： impounding density current eutrophication the Xiangxi Bay the Three Gorges Reservoir

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HYBRID SIMULATION OF THE HYDRAULIC CHARACTERISTICS AT RIVER AND LAKE CONFLUENCE

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Journal of Hydrodynamics 2011年第1期23卷 105-113页

作者： LIU Shi-he CAO Bing college of water Resource and {2. Wuhan University Wuhan 430072 China

The hydraulic characteristics at the confluence reach of river and lake are influenced by multiple factors such as inflow,topography and vegetation resistance,and are very *** this article,the confluence reach of Yangtze River and Dong-ting Lake is selected as a special example and a hybrid model is built to study the flow at this confluence,with the consideration of the interactions between aquatic vegetation and *** tests and calculations show that the model is effective and highly *** simulations show that the separation levee at the confluence reach may change the discharge capacity in the flood plain,which would be enhanced in the upper reach of the levee,hardly changed in the middle reach and reduced at the lower ***,the separation levee also limits the water exchange between the Yangtze River and Dong-ting Lake.

关键词： confluence reach hybrid model separation levee discharge capacity in flood plain

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TURBULENT COHERENT STRUCTURES IN CHANNELS WITH SAND WAVES

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Journal of Hydrodynamics 2001年第2期13卷 106-110页

作者： Liu, S.H. Coll. of water Res. and hydropower Wuhan Univ. Wuhan 430072 China

Sand wave bed is one of the typical shape of complicated boundaries in hydraulics and river dynamics, and sand wave motion is the main form of the bed load motion in rivers, thence the study of turbulent structure over sand waves is of importance both in theory and practice. In this paper turbulent coherent structures over single-and multi-sand waves were studied experimentally, the formulae for the separation length and vortex shedding period of the turbulent flow over single-sand wave were suggested, and the characteristics of turbulent coherent structures over multi-sand waves were also given.

关键词： Sand Sediments Turbulence Two phase flow

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ANALYSIS OF SOLUBLE CHEMICAL TRANSFER BY RUNOFF water IN FIELD

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Journal of Hydrodynamics 2008年第3期20卷 382-390页

作者： TONG Ju-xiu YANG Jin-zhong State Key Laboratory of water resources and {2. engineering Science Wuhan University Wuhan430072 China

In order to determine the main factors influencing soluble chemical transfer and corresponding techniques for reducing fertilizer loss caused by runoff in irrigated fields, a physically based two-layer model was developed with incomplete mixing theory. Different forms of incomplete mixing parameters were introduced in the model, which was successfully verified with previous published experimental data. According to comparison, the chemicals loss of fertilizer is very sensitive to the runoff-related parameter while it is not sensitive to the infiltration-related parameter. The calculated results show that the chemicals in infiltration water play an important role in the early time of rainfall even with saturated soil, and it is mainly in the runoff flow in the late rainfall. Therefore, prevention of shallow subsurface drainage in the early rainfall is an effective way to reduce fertilizer loss, and the coverage on soil surface is another effective way.

关键词： soluble chemical transfer runoff incomplete mixing sensitive infiltration

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COMPOSITE ELEMENT MODEL FOR ROCK MASS SEEPAGE FLOW

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Journal of Hydrodynamics 2006年第2期18卷 219-224页

作者： CHEN Sheng-hong FENG Xue-min State Key Laboratory of water resources and {2. engineering Science Wuhan UniversityWuhan 430072 China

In this paper, the algorithm developed on the concept of the Composite Element Method （CEM） is proposed for the seepage flow in discontinuous rock masses, The basic idea is that if an element contains one or more discontinuity segments, it will be denoted as a composite element having a set of hydraulic potential values defined at its nodes. By the variation principle, the governing equation can be established to solve the unknown hydraulic potential values at the composite element nodes. The main advantage of the proposed model is that the generation of calculation mesh will not be restricted strongly by the number, the position and the orientation of the discontinuities, A numerical example is presented at the end of the paper, to show the validity of the proposed model.

关键词： Composite Element Method(CEM) rock mass seepage flow

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RAIN INTENSITY DISTRIBUTION IN THE SPLASH REGION OF ATOMIZED FLOW

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Journal of Hydrodynamics 2006年第3期18卷 362-366页

作者： DUAN Hong-dong LIU Shi-he LUO Qiu-shi HUANG Wei School of water Resource and hydropower Wuhan University Wuhan 430072China water resources and {2. Planning and Design General Institute MWR Beijing 100011 China

Atomized flow is an unnatural two-phase flow produced while water discharges in water release structures. This flow might threaten the normal operation of hydraulic and hydroelectric installations owing to the unnatural and high-density rain as well as the unnatural and dirty mist. The splash region, the region with the highest rain intensity, hence should receive much attention during the design and operation of the hydraulic and hydroelectric installations. In this paper rain intensity distribution in the splash region of the atomized flow is investigated experimentally, and the method of random simulation is used to predict the rain intensity distribution in the splash region.

关键词： atomized flow splash rain intensity

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MATHEMATICAL MODEL FOR THE FLOW WITH SUBMERGED AND EMERGED RIGID VEGETATION

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Journal of Hydrodynamics 2009年第5期21卷 722-729页

作者： HUAI Wen-xin CHEN Zheng-bing HAN Jie ZHANG Li-xiang ZENG Yu-hong State Key Laboratory of water resources and {2. engineering Science Wuhan University Wuhan430072 China Department of engineering Mechanics Kunming University of Science and Technology Kunming 650051 China

The article summarizes previous studies on the flow in open channels with rigid vegetation, and constructs a mathematical model for submerged and emerged rigid vegetation. The model involves the forces balance in the control volume in one-dimensional steady uniform flow. For submerged vegetation, the whole flow is divided into four regions： external region, upper vegetated region, transition region and viscous region. According to the Karrnan similarity theory, the article improves the mixing length expression, and then gives an analytical solution to predict the vertical distribution of stream-wise velocity in the external region. For emerged vegetation, the flow is divided into two region： outer region and viscous region. In the two circumstances, the thicknesses of each region are determined respectively. The comparison between the calculated results and our experimental data and other researchers＇ data proves that the proposed model is effective.

关键词： Karman similarity theory mixing length submerged and emerged rigid vegetation velocity distribution

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Experiments on Development of Channel Pattern in the Process of River Reformation

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四川大学学报（工程科学版） 2005年第S1期37卷 128-132页

作者： ZHANG Junyong CHEN Li LIU Yucheng DING Zhiliang(State Key Lab.of water resources and {2. Eng.Sci.,wuhan Univ.,wuhan 430072,china) Lab. of water resources and {2. Eng. Sci. Wuhan Univ. Wuhan 430072 China

The changing of flow conditions caused by construction of hydro-projects will result in river's refor- mation and development of channel *** this paper,the development of channel pattern in the process of reformation is studied by means of flume *** of slope,grain size,angle-of-inflow,dis- charge and discharge process are comprehensively analyzed according to the experimental *** was found that the channel would be widened as the river slope or discharge increased and grain s...

关键词： reformation process channel pattern angle-of-inflow discharge process

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Non-Uniform Sediment Transport Downstream from Reservoir

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Transactions of Tianjin university 2008年第4期14卷 263-270页

作者：李义天陈飞 State Key Laboratory of water resources and {2. engineering Sciences Wuhan University

The transport characters of non-uniform sediment before and after the reservoir operation are compared and analyzed. Field data from the Three Gorges Reservoir (TGR), Danjiangkou, and Sanmenxia reservoir indicate that the transport character of coarse particle is various in different reaches. Before the reservoir operation, the dramatic decrease of the hydraulic condition in some reaches is the main reason to cause the coarse particle deposited. After the reservoir operation, almost all grain sized sediment may be eroded, when the reach is eroded seriously. However, the transport character of the coarse particle will be consistent with what it was before, when the reach is not eroded seriously. The deposition amount will be less than its pre-dam value, and it will tend to decrease with the time going on. Erosion of fine particle results from its unsaturation. Longdistance erosion downstream from reservoir is caused by shortage of the supply from riverbed, especially the shortage of fine particle.

关键词： downstream from reservoir grain sized sediment hydraulic condition

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Development of distributed time-variant gain model for nonlinear hydrological systems

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Science china Earth Sciences 2005年第6期48卷 713-723页

作者： XIA Jun1, 2. WANG Gangsheng1, TAN Ge1, YE Aizhong2.& G. H. Huang3 1. Key Laboratory of water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural resources Research, Chinese Academy of Sciences, Beijing 100101,{2. 2. State Key Laboratory of water resources & hydropower engineering Sciences, wuhan university, wuhan 430072,{2. 3. Faculty of engineering, university of Regina, 3737 Wascana Parkway, Regina, Sask., S4S 0A2. Canada Correspondence should be addressed to Xia Jun 1. Key Laboratory of water Cycle & Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. State Key Laboratory of water resources & {2. engineering Sciences Wuhan University 430072 Wuhan China 3. Faculty of engineering University of Regina 3737 Wascana Parkway S4S 0A2 Sask Regina Canada

In this paper, a rainfall-runoff modeling system is developed based on a nonlinear Volterra functional series and a hydrological conceptual modeling approach. Two models, i.e. the time-variant gain model (TVGM) and the distributed time-variant gain model (DTVGM) that are built on the platform of Digital Elevation Model (DEM), Remote Sensing (RS) and Unit Hydro-logical Process were proposed. The developed DTVGM model was applied to two cases in the Heihe River Basin that is located in the arid and semiarid region of northwestern china and the Chaobai River basin located in the semihumid region of northern china. The results indicate that, in addition to the classic dynamic differential approach to describe nonlinear processes in hy-drological systems, it is possible to study such complex processes through the proposed sys-tematic approach to identify prominent hydrological relations. The DTVGM, coupling the advan-tages of both nonlinear and distributed hydrological models, can simulate variant hydrological processes under different environment conditions. Satisfactory results were obtained in fore-casting the time-space variations of hydrological processes and the relationships between land use/cover change and surface runoff variation.

关键词： hydrological process, nonlinearity, time-variant gain model, distributed hydrological model.

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