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Modified vegetation-erosion dynamics model and its application in typical watersheds in the Loess Plateau

International Journal of Sediment research 2011年第01期26卷 78-86页

作者： CHEN Yuehong~1,WANG Feixin~2,LIU Guangquan~3,YU Xinxiao~4, JIA Guodong~5,and GAN Ping~6 china institute of water resources and hydropower research,beijing 100048 International research and Training Center on Erosion and Sediment research,beijing 100048,china beijing Forestry University,beijing 100083,china. Key Lab of Dredging Technology of CCGRP,Shanghai waterway Engineering Design and Consulting Co., Ltd,Shanghai 200120,china. International research and Training Center on Erosion and Sedimentation china institute of water resources and hydropower research,beijing 100048 Northwest A&F University,Yangling 712100,china, beijing Forestry University,beijing 100083,china, beijing Forestry University,beijing 100083,china. china institute of water resources and hydropower research,beijing 100048,and International research and Training Center on Erosion and Sediment research,beijing 100048,china [a] Assoc. Prof. Dr. china institute of water resources and hydropower research beijing 100048 International research and Training Center on Erosion and Sediment research beijing 100048 china beijing Forestry University beijing 100083 china [b] Dr. Key Lab of Dredging Technology of CCGRP Shanghai waterway Engineering Design and Consulting Co. Ltd Shanghai 200120 china [c] Prof. Dr. International research and Training Center on Erosion and Sedimentation china institute of water resources and hydropower research beijing 100048 Northwest A&F University Yangling 712100 china [d] Prof. Dr. beijing Forestry University beijing 100083 china [e] Dr. beijing Forestry University beijing 100083 china [f] Engineer china institute of water resources and hydropower research beijing 100048 and International research and Training Center on Erosion and Sediment research beijing 100048 china

The vegetation-erosion model was applied in three typical watersheds of hilly and gully area in the Loess Plateau in northwestern china to study the dynamic relations between vegetation coverage and soil erosion rate and various *** model was improved by introducing rainfall and runoff *** the modified model was applied in the Luergou and Luoyugou *** calculation results with the modified model were compared with the results of the original *** precisions of simulated vegetation coverage and soil erosion rate with the modified model were greatly improved compared with the original *** erosion rate reduced with increasing vegetation coverage and the human disturbance caused high soil erosion.

关键词： Soil erosion Vegetation coverage Vegetation-erosion dynamics model Loess Plateau Modified model

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Effects of landuse change on surface runoff and sediment yield at different watershed scales on the Loess Plateau

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International Journal of Sediment research 2010年第3期25卷 283-293页

作者： ZHANG Xiaoming1, CAO Wenhong2, GUO Qingchao3, and WU Sihong41 Assoc. Prof. Dr., china institute of water resources and hydropower research, beijing 100048, china, 2,3 Prof. Dr., china institute of water resources and hydropower research, beijing 100048, china, 4 Dr., department of Land and water resources Engineering, Royal institute of Technology, Stockholm, SE-100 44, Sweden [a] Assoc. Prof. Dr. China Institute of Water Resources hydropower research Beijing 100048 China [b] Prof. Dr. China Institute of Water Resources hydropower research Beijing 100048 China [c] Prof. Dr. China Institute of Water Resources hydropower research Beijing 100048 China [d] Dr. Department of Land water resources Engineering Royal Institute of Technology Stockholm SE-100 44 Sweden

Erosion and sediment yield from large and small watersheds exhibit different laws. Variations in surface runoff and sediment yield because of landuse change in four watersheds of different scales from 1 km2 to 73 km2 were analyzed. Due to reforestation and farmland terracing, surface runoff and sediment yield reduced by 20-100% and 10-100% respectively. Reductions in surface runoff were differed significantly under different precipitation regimes. For the large watershed (73 km2) landuse change had similar effects on surface runoff regardless of changing of precipitation. For the small watershed (1 km2) landuse change had fewer effects on surface runoff under high precipitation. The relative changes of sediment yield in the four watersheds under reforestation and farmland terracing decreased as precipitation increased from 350 mm to 650 mm, then increased as precipitation increased from 650 mm to 870 mm. Where initial forest coverage rate was below 45%, sediment yield decreased dramatically as forest coverage rate increased. watershed management with aiming at reducing both surface runoff and sediment yield should be conducted both on sloping surfaces and in channels in large watersheds.

关键词： Soil erosion Land use change Scale effect Surface runoff and sediment yield watershed Loess Plateau

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Node ordinal encoded genetic algorithm for the optimal allocation of water resources

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Progress in Natural Science:Materials International 2005年第5期15卷 448-452页

作者： YANG Xiaohua1*, YANG Zhifeng 1,2, SHEN Zhenyao1 and LI Jianqiang3(1. State Key Laboratory of water environment Simulation, School of environment, beijing Normal University, beijing 100875, china 2. Key Laboratory for water and Sediment Sciences Ministry of Education, School of environment, beijing Normal University, beijing 100875, china 3. water resources and hydropower Planning and Design General institute, MWR, beijing 100011, china) State Key Laboratory of water environment Simulation School of Environment Beijing Normal University Beijing 100875 China Key Laboratory for water and Sediment Sciences Ministry of Education School of Environment Beijing Normal University Beijing 100875 China water resources and hydropower Planning and Design General institute MWR Beijing 100011 China

A new method, node ordinal encoded genetic algorithm (NOEGA), is proposed for solving water resources optimal allocation problems, in which the capacity of water resources is split into a number of smaller parts so that successive operations can be overlapped. Our objective is to maximize the whole benefit function. To overcome the “dimensionality and algorithm complexity curse” while searching for solutions and looking for an optimal solution, the operations of one-point crossover operator, gene exchange operator, gene random operator, gene shift operator and node ordinal strings are established. It is proved to be an effective optimal method in searching for global solutions. The NOEGA does not need a diversity of initial population, and it does not have the problem of immature convergence. The results of two cases show that using NOEGA to solve the optimal allocation model is very efficient and robust. In addition, the algorithm complexity of NOEGA is discussed.

关键词： water resources optimal allocation node ordinal code genetic algorithm.

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Soil erosion and sediment transport in the gullied Loess Plateau:Scale effects and their mechanisms

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Science china(Technological Sciences) 2009年第5期52卷 1283-1292页

作者： LI TieJian1,WANG GuangQian1,XUE Hai2,3 & WANG Kai4 1 State Key Laboratory of Hydroscience and Engineering,Tsinghua University,beijing 100084,china 2 Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,china 3 North china institute of water Conservancy and hydropower,Zhengzhou 450008,china 4 china institute of water resources and hydropower research,beijing 100038,china 1. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China 2. Yellow River Engineering Consulting Co. Ltd. Zhengzhou 450003 China 3. North china institute of water Conservancy and hydropower Zhengzhou 450008 China 4. china institute of water resources and hydropower research Beijing 100038 China

Scale effects exist in the whole process of rainfall-3-runoff-3-soil erosion-3-sediment transport in river basins. The differences of hydrographs and sediment graphs in different positions in a river basin are treated as basic scale effects, which are more complex in the gullied Loess Plateau, a region notorious for high intensity soil erosion and hyper-concentrated sediment-laden flow. The up-scaling method of direct extrapolation that maintains dynamical mechanism effective in large scale application was chosen as the methodology of this paper. Firstly, scale effects of hydrographs and sediment graphs were analyzed by using field data, and key sub-processes and their mechanisms contributing to scale effects were clearly defined. Then, the Digital Yellow River Model that integrates sub-models for the subprocesses was used with high resolution to simulate rainfall-3-runoff-3-soil erosion-3-sediment transport response in Chabagou watershed, and the distributed results representing scale effects were obtained. Finally, analysis on the simulation results was carried out. It was shown that gravitational erosion and hyper-concentrated flow contribute most to the spatial variation of hydrographs and sediment graphs in the spatial scale. Different spatial scale distributions and superposition of different sub-processes are the mechanisms of scale effects.

关键词： scale effect soil erosion hyper-concentrated sediment-laden flow the Loess Plateau

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NUMERICAL COMPUTATION OF VERTICAL TWO-DIMENSIONALNON-EQUILIBRIUM SEDIMENT MOVEMENT

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International Journal of Sediment research 1999年第2期14卷 251-257页

作者： HUANG Yongiian (1 china institute of water resources and hydropower research, P.O.Box 366,beijing 100044.)

Non-equilibrium sediment transport is studied by using a numerical solution of vertical two dimensional diffusion equations. Sediment concentration on the bed is determined as the boundary condition of diffusion equation based the sediment carrying capacity of local flow. The velocity field is solved and then the two dimensional diffusion equations in each section along the flow direction are solved. The vertical distribution of sediment concentration is determined and then the quantities of erosion or siltation are obtained along the cross sections. The usage of this numerical computation method is further explained in unsteady flow examples.

关键词： Non-equilibrium sediment transport Sediment concentration Numerical model Velocity field

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On the formation of couplet-style stratifications

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International Journal of Sediment research 2008年第1期23卷 85-91页

作者： Yu-Hai WANG1, Yan-Hong WANG2, and Li-Qun TANG31 Ph.D., Engineer, department of Sediment research, china institute of water resources and hydropower research, Chegongzhuangxilu 20, beijing 100044, china, 2 Ph.D., Engineer, Nanjing Hydraulic research institute, Hujuguanlu 34, Nanjing 210024, china 3 Ph.D., Prof., department of Sediment research, china institute of water resources and hydropower research, Chegongzhuangxilu 20, beijing 100044, china [a]Ph.D. Engineer department of Sediment research china institute of water resources and hydropower research Chegongzhuangxilu 20 beijing 100044 china [b]Ph.D. Engineer Nanjing Hydraulic research institute Hujuguanlu 34 Nanjing 210024 china [c]Ph.D. Prof. department of Sediment research china institute of water resources and hydropower research Chegongzhuangxilu 20 beijing 100044 china

Couplet-style stratifications refer to the sedimentary sequences that consist of alternating coarse-grain-dominated bed and fine-grain-dominated bed, with or without a sandwiched middle-sized bed. The formation mechanism is complicated due to the interplays of varying driving force (s), sediment supply & transport and topographic configurations. This paper presents a comprehensive overview of such characteristic bedforms, which emerge during the transport and deposition of non-uniform sediments. The leading formative models include water-stage variation, gravel-overpassing process, superimposition of bedload sheets and avalanching process (inverse grading). Each process might produce similar or distinct sedimentological features with respect to grading, matrix content, grain attitude, bounding faces between beds and internal longitudinal/transverse geometry. The couplet-style stratified strata might play an active role in landscape evolution.

关键词： Couplet-style stratification Formative model Sedimentological features Landform

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EXPERIMENTAL INVESTIGATIONS ON BUBBLE COLLAPSE NEAR BOUNDARIES

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Journal of Hydrodynamics 1997年第2期9卷 78-85页

作者： Lu Lichina institute of water resources and Hydro. Power research, beijing 100038, P. R.chinaHuang Ji-tang, Xu Xie-qingTsinghua University, beijing 100084, P.R. china china Inst of water resources and Hydropower Research Beijing China

Collapse of a spark-generated bubble near rigid or deformable surfaces is studied experimentally with a high speed cammera. The formation of a bubble wall jet has been observed and discussed. Results from experimental... 详细信息

关键词： bubble collaps cavitation

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A NON-UNIFORM SEDIMENT TRANSPORT MODEL WITH THE BOUNDARY-FITTING ORTHOGONAL COORDINATE SYSTEM

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Journal of Hydrodynamics 2002年第1期14卷 64-68页

作者： Lu Yong-jun (River and Harbor department, Nanjing Hydraulic research institute , Nanjing 210024, china) Chen Guo-xiang (College water resources and environment, Hohai University, Nanjing 210024, china) River and Harbor department Nanjing Hydraulic Research Institute Nanjing 210024 China College water resources and environment Hohai University Nanjing 210024 china

A 2-D non-uniform sediment mat hmatical model in the boundary-fitting orthogonal coordinate system was develop ed in this paper. The governing equations, the numerical scheme, the boundary con ditions, the movable boundary technique and the numerical solutions were present ed. The model was verified by the data of the reach 25km upstream the Jialingjia ng estuary and the 44km long main stream of the Chongqing reach of the Yangtze r iver. The calculated results show that, the water elevation, the velocity distri bution and the river bed deformation are in agreement with the measured data.

关键词： mathematical model non-uniform sus pended load non-uniform bedload boundary-fitting orthogonal coordinate system

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An ideal interval method of multi-objective decision-making for comprehensive assessment of water resources renewability

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Science china(Technological Sciences) 2004年第z1期47卷 42-50页

作者： YANG Xiaohua1, YANG Zhifeng1,2, SHEN Zhenyao1 & LI Jianqiang3 1. School of environment, State Key Laboratory of water environment Simulation, beijing Normal Univer- sity, beijing 100875, china 2. School of environment, Key Laboratory for water and Sediment Sciences of Ministry of Education, beijing Normal University, beijing 100875, china 3. water resources and hydropower Planning and Design General institute, MWR, beijing 100011, china beijing Normal Univ Sch Environm State Key Lab Water Environm Simulat Beijing 100875 Peoples R China beijing Normal Univ Sch Environm Key Lab Water & Sediment Sci Minist Educ Beijing 100875 Peoples R China MWR Water Resources & Hydropower Planning & Design Ge Beijing 100011 Peoples R China

In order to estimate water resources renewability scientifically, an Ideal Interval Method of Multiple Objective Decision-Making (IIMMODM) is presented. This method is developed through improving an ideal point method of multiple objective decision-making. The ideal interval is obtained with assessment standard instead of ideal points. The weights are decided by using the basic point and gray code accelerating genetic algorithm. This method has synthesized the expert’s suggestion and avoided giving a mark for the objective again. It could solve the complicated problem of compatible or incompatible multi-objective assessment. The principle of IIMMODM is presented in this paper. It is used to assess the water resources renewability for nine administrative divisions in the Yellow River basin. The result shows that the water resources renewability in the Yellow River basin is very low. Compared with the gray associate analysis method, fuzzy synthesis method and genetic projection pursuit method, the IIMMODM is easier to use. Compared with the ideal point method of multiple objective decision-making, the IIMMODM has good robustness, which is applicable to the comprehensive assessments of water resources.

关键词： water resources renewability, comprehensive assessment, multiple objective decision-making,ideal interval, Yellow River basin.

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Differential Hydrological Grey Model (DHGM) with self-memory function and its application to flood forecasting

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Science china(Technological Sciences) 2009年第4期52卷 1039-1049页

作者： CHEN XiangDong1, XIA Jun1,2 & XU Qian3 1 Key Laboratory of water Cycle and Related Land Surface Processes, institute of Geographic Sciences and Natural resources research, Chinese Academy of Sciences, beijing 100101, china 2 State Key Laboratory of water resources and hydropower Engineering Science, Wuhan University, Wuhan 430072, china 3 School of Hydrology and water resources, Hohai University, Nanjing 210098, china 1. Key Laboratory of water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 2. State Key Laboratory of water resources and hydropower Engineering Science Wuhan University Wuhan 430072 China 3. School of Hydrology and water resources Hohai University Nanjing 210098 China

This paper addresses a problem of flood forecasting with the self-memory function. Considering flood forecasting’s uncertainty and updating demand, a hybrid hydrological model, namely Differential Hy- drological Grey Model with self-memory function (DHGM-SM), is developed. The model has two fold features. One is to establish a self-memorization equation linked with DHGM, that could extract useful information from past data series and realize updating of hydrological dynamic process. The other is that this model has higher efficiency relative to original hydrological model without self-memory func- tion. This approach was applied to river flow forecasting of two representative basins in Tunxi of South china and Daqinggou of North china. It is shown that this hybrid method has satisfactory forecasting accuracy by examination of both calibration and validation.

关键词： differential grey model the self-memorization principle real-time forecasting faded-memory recursive least square method

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