HAN Qi wei1, LI Yun
zhong2
(1.China Instituie of Water Resources and Hydropower Research;2.Changjiang Water Resources
Commission)
Abstract: This paper is concerned with the general laws of flow process and fluvial process in the front area of the dam site of the Three Gorges Reservoir during the 1st and 2nd periods of cofferdam construction, especially including the characteristics of flow and sediment transportation, the mechanism of sedimentation and erosion, the equilibrium area and retention area, as well as the influence of cross section shrinkage on deposition and erosion.
Key words: Runoff reservoir£»Sediment transport;Fluvial process£»Equilibrium area;Retention area
Erosion-Resisting Characteristics of Blocks on Groin Head in Micro-Tidal River Mouths
YANG Huo qi, WANG Wen jie
£¨Zhejiang Institute of Hydraulics of Estuary£©
Abstract: By investigation on large block's application to groin head as erosioncontrol and experimental study of block's stability with bore-generated laboratory flume, the paper analysed the success and failure experiences that the large blocks were used as the erosion control on the groin head . At the same time, according to the result of the experiment , the paper put forward the methods to improve the effect of blocks as the groin head protection.
Key words: Qiantangjiang estuary; Groin head; Block; Tidal bore; Erosion-resisting characteristic; Stability
Prediction of River Bank-Line Deformation Using Artificial Neural Network
(1.Dept.River Engineering,Wuhan University;2.Hydrology Bureau,Yangtze River Water Resources Commission)
Abstract: With BP artificial neural network,a model is developed to predict river bank-line lateral evolution.The model has been used to a typical case to analyze evolution of Shishou bend in middle Yangtze River.By using the two methods,calculated results show that the model can successfully predict the changes of bank line at both inlet and outlet reaches of Shishou bend.The model is flexible and can be used to predict changes of river bank line.
Key words: Fluvial process;Lateral evolution;Artificial neural network;Prediction model
Sidewall Effects of Wind Tunnels on Velocity Profiles in Blown Sand Flow
LI Zhen shan1, 3, NI
Jin ren2, 3, WANG Guang qian1, 3
(1. Department of Hydraulic Engineering, Tsinghua University; 2.Center for Environmental
Sciences, Peking University;
3. The Key Laboratory of Water and Sediment Sciences, Ministry of Education)
Abstract: This paper presented the sidewall effects of wind tunnels on velocity profiles of airflow with saltating grains. Wind velocity profiles in cross sections were measured in terms of five aspect ratios (width/height) of 1.00, 0.83, 0.67, 0.50, and 0.33, respectively. Results show that the sidewall exerts significant effects on the parameters of vertical profiles of wind velocity. In a cross section, the effective roughness corresponding to the central vertical profile is greater than those in other vertical profiles. The wind friction velocity as well as the upper edge heights for velocity profiles in either inner or outer saltation regions increase from the sidewall to the central line of wind tunnels. Both the ratio of friction velocity to free stream wind velocity and the thickness of airflow are subject to the sidewall effect, showing the increase trend with the decreasing aspect ratios.
Key words: Sidewall effect; Blown sand flow; Wind velocity profile; Wind tunnel experiment; Aspect ratio
Analyses on Distribution Rule of Turbulence Intensity along Depth
DENG An-jun1, CHEN Li2,
LING Peng2, YE Xiao-yun2
(1.China Institute of Water Resources and Hydropower Research;
2.Wuhan University of Hydraulic and Electric Engineering,Lab of Sediment)
Abstract: By using the flume experimental data by Micro ADV in sediment-laden flow, and analyzing the data from LDV and Strain-kinemometer, the quantify relationship of the turbulence intensity with the velocity and its gradient is established. Additionally, by using the numerical examination method, the affects of the factors such as the max velocity umax, the shear velocity u*, and Karman constant ¦Ê on the location of the maximum turbulence intensity along depth are analyzed.
Key words: Turbulence intensity; Sediment-laden flow; Velocity; Velocity gradient; Micro ADV
Primary Study on Surface Properties of Suspended Particles in the Changjiang Estuary
LI Dao ji, ZHANG Jing, ZHANG Li
hua, CHEN Bang-lin, CHEN Ji-yu
(State Key Laboratory of Estuarine and Coastal Research, East China Normal University)
Abstract: Suspended fine particle sizes and their fluoresce properties dyed and un-dyed by FITC on surface water of the Changjiang estuary were analyzed by FACScan flow Cytometer, without or with following different treatments: NaPO3 and H2O2 plus ultrasonic, NaPO3 plus ultrasonic, ultrasonic, NaPO3 and H2O2, NaPO3, and contrast. The results showed that removing organic matters made particle size obviously changed. It is suggested that surface of suspended fine particles combined with some organic matters, making particle size enlarging, and absorption of suspended particles to heavy metals be mainly carried out through the surface organic matters.
Key words: Suspended particle; Surface property; the Changjiang estuary
Study on Finite Element Methods Applied to Convection-Dominated Sediment Movement Modeling
LIU Hai-tao, JI Zu-wen, HU
Chun-hong
(China Institute of Water Resources and Hydropower Research)
Abstract: An application of the upwind and characteristic finite element method(FEM) to the convection-dominated sediment movement modeling is reported in this paper. The two improved FEMs above are studied for the coupling solution of the governing equations of hydrodynamics, sediment movement and bed deformation. Accordingly, the improved computational programs are compiled based on an established hydrodynamic model. The numerical experiments indicate that they are all available to deal with the convection term, and especially, the characteristic FEM is more fit for the modeling of sediment movement in the flow field including vertical-axis circumfluence, even if this new FEM needs a little more time spent in the calculation.
Key words: Convection-dominated suspended sediment movement; Upwind FEM; Characteristic FEM; the Governing equation of sediment movement
Abstract: On the basis of rules of the soil erosion and sediment yield of the hilly loess region,the soil erosion and sediment yield models about the hillslope,the valley slope and the channel in the Yandaogou small basin in West Shaxi province were established. Supported by analysis of GIS,the drainage networks of the small basin were calculated and introduced to the models.Through the testing calculation of single storm and annual storms,the models showed a good agreement with the measured data.
Key words: the Hilly Loess region; Geographical information system(GIS); Drainage networks; Plots; Soil erosion and sediment yield model
A Study on Countermeasure of Flood Control in Dongting Lake
LI Xi-chun1,DUAN Wen-zhong2, YU Ming-hui2, ZHENG Ya-hui3Abstract: Since 1949£¬due to the sediment deposit and land reclamation, the water surface area and storage capacity in Dongting Lake have shrunk by 1 727km
2 and 126¡Á108m3,respectively.The flood level in Dongting Lake is raised over 1m. The cut-offs in the lower Jingjiang River made a faster shrinkage of the three mouths in Jingjiang reach to Dongting Lake and caused a significant change of the relationship between the Jingjiang River and Dongting Lake¡£The deposition in the reach from Chenlingji to Loushan raised the water level at Chenlingji, which is the outlet of Dongting Lake to Yangtze River. As a result, the flood level in Dongting Lake becomes higher and the situation of flood control is very serious. It is difficult in the near future to lower the water level in Chenlingji. Therefore the primary ways to control flood in Dongting Lake should return the farmland to the Lake, raise the dike, and dredge the Lake¡£Key words: Flood level; Flood control; Dongting Lake; Jingjiang River
Calibration of the Image Distortion in Measuring Velocity Field with PIV
YU Ming-zhong£¬WANG Xing-kui£¬PANG Dong-ming£¬WANG Dian-changAbstract: The error of image geometric distortion induced by the CCD camera greatly reduces the computational precision when using PIV technique to measure the velocity field. The properties of the image distortion were investigated and the distortion error in various imaging systems was acquired from experiments. Thus, calibration formulas were obtained. The error after calibration was less than 0.4 pixel for the recommended system.
Key words: CCD camera calibration; PIV.
Abstract: Warping is one component of the policy "Retaining, Discharging, Warping, Regulation, and Dredging Comprehensive Treatment" for Yellow River. By utilizing existing diversion works in the floodplain area of the lower reach and sediment resources during medium and small sized flood, warping, which is proved to be an effective way to raise the capablity of dikes and floodplains to fight against floods in Yellow River, could strengthen dikes, improve the soil, eliminate dangerous situations by floods, and improve ecological environment in floodplains. Based on the practices, the article puts forward the engineering arrangements, planning and design, and technical measures for warping.
Key words: Downstream Yellow River£»Improving soil by warping£»Strengthening dike by warping
Abstract: A serious deposition has been observed in the basin of the intake of the WEPP since its first stage was completed. The engineering layout of its second stage has a close relationship with sedimentation. After analyzing the reason of sedimentation in the basin, the ultimate sedimentation thickness and flow depth under the mean tidal level in the area of the intake of the second stage of the WEPP are estimated by the calibrated formulas.
Key words: Basin of the power plant;Sedimentation analyses; Estimation of the ultimate sedimentation
Estuarine Sediment Fluxes:An Overview
WU Hua-lin1£¬2, SHEN Huan-ting1, ZHU Jian-rong1
(1.State Key Laboratory of Estuarine and Coastal Research,East China Normal University;
2.Estuary and Coast Research Center, Ministy of Communications)
Abstract: Study on estuarine sediment fluxes has both scientific and engineering significances.This paper summarized the new development and progress in the study of estuarine sediment fluxes.Research on sediment flux was mostly conducted by the method of hydrological statistics,calculation of sectional flux,numerical model.Both hydrological statistics and calculation of sectional flux cannot predict the sediment transport process,so the numerical model is more useful.However,the development of estuary sediment model is hampered because the physical mechanism of estuarine sediment transport is still poorly understood due to its complexity.Based on the analysis,the paper prospects the future research work in this field.
Key words: Estuary; Sediment; Flux; Progress; Global change
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