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Estimating instantaneous concentration of suspended sediment using acoustic backscatter from an ADV

International Journal of Sediment Research 2019年第5期34卷 422-431页

作者： Wenjie Li Shengfa Yang Wei Yang Yi Xiao Xuhui Fu Shuaishuai Zhang National Inland Waterway Regulation Engineering Research Center Chongqing Jiaotong University changjiang Chongqing Harbour and Waterway Engineering investigation and Design Institute

The measurement of instantaneous sediment concentration remains a challenging task. In this study, a three-step procedure is proposed to estimate instantaneous sediment concentration using acoustic backscatter from Acoustic Doppler Velocimeter(ADV). The influences of acoustic noise and particle diameter on an ADV’s performance was first tested in the laboratory, then the three-step procedure was verified based on field measurements in the Zhongxian and Fengjie reaches in the Three Gorges Reservoir. The first step involves reconstructing the backscatter signal time series. Due to contamination from both the noise floor and spurious spikes, the denoising-despiking method was applied instead of the traditional velocity-despiking methods, and this approach performed well based on spectrum analysis. The second step involves calibrating the sediment concentration against the backscatter signal.A linear relation, whose slope and intercept were calibrated to be dependent on particle diameter, is proposed in double logarithmic coordinates. The third step involves calculating the instantaneous sediment concentration using reconstructed instantaneous backscatter based on the proposed *** accuracy of the proposed method was evaluated through consideration of the concentration spectrum and sediment flux, indicating that the proposed three-step procedure is effective for the measurement of instantaneous sediment concentration.

关键词： Instantaneous sediment concentration Acoustic backscatter intensity Denoising-despiking Particle diameter Acoustic Doppler Velocimeter

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Determination of Vessel Attitudes Using GPS

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Journal of China University of Mining and Technology 2002年第1期12卷 77-80页

作者：王书寅周丰年金建霞吴敬文 changjiang River Estuary investigation Bureau of Hydrology and Water Resources Changjiang Water Resources Commission Taicang Jiangsu 215431 P.R. China

With the development of GPS carrier wave phase technology, it becomes possible that the height accuracy of centimeter level is got by GPS RTK technology. Vessel attitudes are very important parameters in marine survey. In this paper, they were determined by 4 GPS receivers. At the same time, the arithmetic and procedure of vessel attitude determining were given. Based on an experiment, some useful conclusions were obtained and the corresponding methods were put forward to improve the accuracy.

关键词： determination of vessel attitudes with GPS vessel attitude GPS carrier wave phase experiment

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Geometrical Design and Hydraulic Feasibility of Inner-Reinforced Girders in Hydropower Bifurcations

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Transactions of Tianjin University 2017年第5期23卷 461-470页

作者： Zhimin Zhang Hegao Wu Yang Wang Qiling Zhang Teng Li State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072China changjiang Institute of Survey Planning Design and Research Wuhan 430010 China changjiang River Scientific Research Institute Wuhan 430010 China

Inner-reinforced girders, also known as ribs, are widely used in hydropower bifurcations. However, while they strengthen structures, they also cause energy loss. This work aims to develop an appropriate geometry form for ribs that can diminish head loss in hydropower bifurcations. The term rib/breadth ratio (RBR) is defined to describe the geometrical form of ribs. An investigation is conducted to study the flow and performance characteristics of bifurcations with ribs using computational fluid dynamics. The dependence of the head loss coefficient on the RBR is given in six working conditions. Results show that the ribs change the local flow patterns and slightly increase the water head loss in some cases. In other cases, however, the ribs make the flow smooth. An appropriate RBR is the key to improve the flow patterns in hydropower bifurcations. The head loss varies with the RBR and reaches the minimum when the RBR is 0.3. © 2017, Tianjin University and Springer-Verlag GmbH Germany.

关键词： Computational fluid dynamics Energy dissipation Flow patterns Fluid dynamics Geometry Hydroelectric power Reinforcement

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EXPERIMENTAL FEEDBACK ON THE investigation OF HYDRAULIC CHARACTERISTICS FOR THE SHIP-LOCK FILLING AND EMPTYING SYSTEM OF TGP

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Journal of Hydrodynamics 2005年第6期17卷 770-775页

作者： NIU Xin-qiang JIANG Xiao-min School of Hydropower and information Engineering Huazhong University of Science and TechnologyWuhan 430074 China changjiang Institute of Survey Planning Design and Research CWRC Wuhan 430010 China

Where hydraulic characteristics of ship lock filling and emptying system are concerned, there are much bigger differences between prototype and model experiments. Based on the results of the prototype experiments fur the Three Gorges Project （TGP）, experiments on the feedback model were conducted of the ship-lock filling and emptying system, by means of technologies of drag reduction, under similar conditions as the operation of the prototype project. The experimental results show that the difference of drag co efficient reached-44% hetween the prototype and the model for the filling and emptying system of the ship-lock No. 3 for TGP and the difference of discharge coefficient was ahout 33% between them. The technologies of drag reduction are more efficient in the simulation of a ship lock filling and emptying system in order to he consistent for discharge, water level, time average pressure and pulsating pressure between prototypes and models.

关键词： hydraulic characteristics filling and emptying system ship-lock feedback experiment

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Regulation characteristics of underlying surface on runoff regime metrics and their spatial differences in typical urban communities across China

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Science China Earth Sciences 2022年第8期65卷 1415-1430页

作者： Yongyong ZHANG Jinjin HOU Jun XIA Dunxian SHE Shengjun WU Xingyao PAN Institute of Geographic Sciences and Natural Resources Research Key Laboratory of Water Cycle and Related Land Surface ProcessesChinese Academy of SciencesBeijing 100101China changjiang investigation PlanningDesign and Research Co.Ltd.Wuhan 430014China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400417China Beijing Key Laboratory of Urban Water Cycle and Sponge City Technology Beijing 100048China

The regulation and spatial differences of urban runoffs are of great concern in contemporary hydrological ***,owing to a shortage of basic data sources and restrictions on urban hydrological simulation functions,simulating and investigating the regulation mechanism behind rainfall-runoff processes remain significantly *** this study,the Time Variant Gain Model(TVGM),a hydrological nonlinear system model,was extrapolated to the hydrodynamic model of an urban drainage network system by integrating it with the widely used Stormwater Management Model(SWMM)to adequately simulate urban runoff events while considering various underlying surfaces and runoff routing modes,such as surface,drainage network and river runoff,in urban regions(i.e.,TVGM-SWMM).Moreover,runoff events were characterized using the following four runoff regime metrics:runoff coefficient,capture ratio of annual runoff volume,standardized flood timescale,and the ratio of occurrence time differences between flow and rainfall peak to event duration(peak flow delay time).The characteristics and spatial differences of urban runoff regulations were investigated,and the key impact factors and their relative contributions were identified using multivariate statistical *** communities were selected as our study areas,consisting of communities from Beijing,Shenzhen,Wuhan,and *** results showed that the TVGM-SWMM performed considerably better than SWMM *** comprehensive simulation accuracy of 60%of the events(12/20)improved by 4-86%,with the bias improving the most,followed by the efficiency *** the runoff coefficient,significant spatial differences were identified at the patch scale for the runoff regime metrics,with differences of 0.43,0.22,and 0.16(p<0.05).The key impact factors were the pipe length(r=0.51)in the drainage network system and the forest area ratios(r=0.56),sponge measures(r=0.52),grassland(r=0.48),and impervious surface(r=0.46)in t

关键词： Runoff event Regime metrics Spatial differences Urban rainfall-runoff model Underlying surface regulation

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investigation of non-cohesive levee breach by overtopping flow

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Journal of Hydrodynamics 2013年第4期25卷 572-579页

作者：余明辉魏红艳梁艳洁赵勇 State Key Laboratory of Water Resources and Hydropower Engineering Sciences Wuhan University State Yellow River Engineering Consulting Co. Ltd. changjiang Engineering Supervision and Consulting Co.

This paper presents an experimental study of the overtopping breach of homogeneous non-cohesive levee or dike in a 180°bend rectangular flume. Detailed experimental and numerical results provide information on the breach flow discharge and longitudi- nal and transversal breach profiles for this type of levee. It is indicated that the water level and the flow discharge in the river and the levee material properties are significant influencing factors for the breach evolution. The plane form of the breach is approximately an asymmetrical hyperbola. A formula with a non-constant flow factor is proposed to compute this kind of breach discharge.

关键词： non-cohesive levee overtopping breach discharge experiments

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Dyke Foundation Classification

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人民长江 2001年第z1期32卷 37-40页

作者： ZHANG Jia fa Professor, Yangtze River Scientific Research Institute, Wuhan 430010, China. MA Gui sheng Senior Engineer, Bureau of Exploitation & investigation, changjiang Water Resources Commission, Wuhan 430010, China. LI Chang cheng Associate Pr Professor Yangtze River Scientific Research Institute Senior Engineer Bureau of Exploitation Investigation Changjiang Wat er Resources Commission Associate Professor Wuhan University

Main factors, which should be considered in the classification of dyke foundation, are discussed in this paper. Engineering conditions should be taken into account when the levee safety is appraised based on engineering geologic appraisement and classification. On the basis of safety appraisement, dyke foundation may be classified with regard of suitable reinforcement measures. Examples are presented to illustrate the instructive significance of dyke foundation classification to dyke reinforcement design.

关键词： dyke foundation geological classification safety status reinforcement Yangtze Valley

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Numerical investigation of Residence Time Distribution for the Characterization of Groundwater Flow System in Three Dimensions

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Journal of Earth Science 2022年第6期33卷 1583-1600页

作者： Jiale Wang Menggui Jin Baojie Jia Fengxin Kang Department of Soil and Water Conservation Changjiang River Scientific Research InstituteWuhan430010China School of Environmental Studies China University of GeosciencesWuhan430078China Research Center on Mountain Torrent and Geologic Disaster Prevention of MWR Wuhan430010China Wuhan changjiang Science&Technology Development Co.Ltd. Wuhan430019China Shandong Provincial Bureau of Geology and Mineral Resources Jinan250013China

How to identify the nested structure of a three-dimensional(3D)hierarchical groundwater flow system is always a difficult problem puzzling hydrogeologists due to the multiple scales and complexity of the 3D flow *** main objective of this study was to develop a quantitative method to partition the nested groundwater flow system into different hierarchies in three dimensions.A 3D numerical model with topography derived from the real geomatic data in Jinan,China was implemented to simulate groundwater flow and residence time at the regional scale while the recharge rate,anisotropic permeability and hydrothermal effect being set as climatic and hydrogeological variables in the *** simulated groundwater residence time distribution showed a favorable consistency with the spatial distribution of flow *** probability density function of residence time with discontinuous segments indicated the discrete nature of time domain between different flow hierarchies,and it was used to partition the hierarchical flow system into shallow/intermediate/deep flow *** changes in the groundwater flow system can be quantitatively depicted by the climatic and hydrogeological *** study provides new insights and an efficient way to analyze groundwater circulation and evolution in three dimensions from the perspective of time domain.

关键词： groundwater flow residence time distribution 3D large-scale basin numerical modeling hydrology

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Experimental investigation on breaching of embankments

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Science China(Technological Sciences) 2011年第2期54卷 148-155页

作者： ZHU YongHui VISSER P J VRIJLING J K WANG GuangQian State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China changjiang River Scientific Research Institute Changjiang Water Resources Commission Wuhan 430010 China Faculty of Civil Engineering and Geosciences Delft University of Technology Delft 2600 GA Netherlands

Breaching of embankments has recently drawn more and more attention due to its importance in the development of early warning systems for embankment failures,in the evacuation plans of people at risk,in the design method of embankments based on a risk-approach,etc. The erosion process observed during embankment breaching tests in the laboratory and the analysis of the results are described in this paper. Five embankments,one constructed with pure sand,four with different sand-silt-clay mixtures were tested. The height of the embankments was 75 cm and the width at the crest was 60 cm. Examination of the data from these tests indicated that headcut erosion played an important role in the process of breach growth in the embankments made of cohesive soil mixtures. Flow shear erosion,fluidization of the headcut slope surface,undermining of the headcut due to impinging jet scour and discrete soil mechanical slope mass failure from the headcut were all observed during these tests. For the embankment constructed with pure sand,the breach erosion process was dominated by shear erosion,which led to a gradual and relatively uniform retreat of the downstream slope. The cohesive proportion in the sand-silt-clay mixtures strongly slowed down the erosion process.

关键词： embankments breaching experiments headcut erosion

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Improved Statically Solvable Slice Method for Slope Stability Analysis

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Journal of Earth Science 2022年第5期33卷 1190-1203页

作者： Aijun Su Mingquan Feng Shan Dong Zongxing Zou Jinge Wang Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan430074China Three Gorges Research Center for Geohazards China University of GeosciencesWuhan430074China changjiang Geotechnical Engineering Corporation Wuhan430074China

Although slice methods are simple and effective slope stability analysis approaches,they are statically *** modifications of the slice method,such as the Spencer,MorgensternPrice,and Chen-Morgenstern methods,are statically determinate and solvable as they assume the inter-slice force inclination angle;however,there is a small gap between the assumptions and actual landslide stability *** reasonable theoretical analysis,the Su slice method provides a reliable approach for determining the inter-slice force inclination angle that can be used in slice analysis to accurately analyse,calculate,and evaluate the stability of ***,the Su slice method requires further research and analysis,especially in terms of the parameter values sinλbiandρ.In this study,we investigated more accurate methods for calculating the parameters sinλbiandρ.In addition,an adjustment coefficient(μ)was introduced to improve the solution method for the inter-slice force inclination *** inter-slice force inclination and safety factors of three landslides with arc-shaped slip surfaces and one landslide with a polyline-shaped slip surface were analysed and compared using the different slice *** improved inter-slice force inclination not only satisfies the calculation of static force equilibrium condition but also satisfies the calculation of both the force and moment equilibrium *** improved method for calculating inter-slice force inclination presented the best *** safety factors calculated using the improved Su slice method were close to those obtained using numerical simulations and the Morgenstern-Price *** negligible differences among the safety factors calculated using the Su slice,improved Su slice,and M-P methods,the accuracy of the improved Su slice method was better than the M-P method in terms of inter-slice force inclination angles which can be useful to improve protection engineering design.

关键词： slope stability limit equilibrium analysis slice method inter-slice force inclination geological hazards

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