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Efficiency of sediment transport by flood and its control in the Lower yellow river

Science china(Technological Sciences) 2004年第z1期47卷 173-185页

作者： NI Jinren1, LIU Xiaoyong2, LI Tianhong1, ZHAO Ye’an3.& JIN Ling1 1. Department of Environmental Engineering, Peking University The Key Laboratory of Water and Sedi- ment Sciences, Ministry of Education, Beijing 100871, china 2. General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Re- sources, Beijing 100011, china 3. the yellow river conservancy commission,{3., china 1. Department of Environmental Engineering Peking University 100871 Beijing China 2. The Key Laboratory of Water and Sediment Sciences Ministry of Education 100871 Beijing China 3. General Institute of Water Resources and Hydropower Planning and Design Ministry of Water Resources 100011 Beijing China 4. The yellow river conservancy {3. 450003 Zhengzhou China

This paper presents the characteristics of sediment transport by flood in the Lower yellow river with the reach from Huayuankou to Gaocun, which is regarded as a typical braided pattern. The Artificial Neural Network Model on Water Use for Sediment Transport (WUST) by flood was established based on the measured data from 1980 to 1998. Consequently, simulations of controlling process of sediment transport by flood were made in terms of the control theory under different scenarios. According to the situation of sediment transport by flood in the Lower yellow river, Open-Loop control system and feedback control system were adopted in system design. In the Open-Loop control system, numerical simulations were made to reveal the relationship between average discharge of flood and the WUST with varying sediment concentrations. The results demonstrate that sediment concentration has significant influence on the controlling process of flood flow to WUST. It is practical and efficient to control WUST if sediment concentration is less than 20 kg/m3. In the feedback control system, controlling processes of sediment concentration and flood discharge for sediment transport were simulated respectively under given conditions, and it was found that sediment transport process could be controlled completely by sediment concentration and discharge at the inlet of the reach from Huayuankou to Gaocun. Using the same method, controlling processes of sediment transport by flood in other reaches in the Lower yellow river were also simulated. For the case of sediment concentration being 20 kg/m3. the optimized controlling discharge ranges from 23.0 to 2900 m3.s in the lower reach of Huayuankou. This study is also of significance to flood control and flushing sediment in the Lower yellow river with proper operation modes of Xiaolangdi Reservoir.

关键词： the Lower yellow river, flood, sediment transport, efficiency, simulation, control.

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Study on the changes of water cycle and its impacts in the source region of the yellow river

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Science china(Technological Sciences) 2004年第z1期47卷 142-151页

作者： ZHANG Shifeng1, JIA Shaofeng1, LIU Changming1, CAO Wenbing2, HAO Fanghua3. LIU Jiuyu4 & YAN Huayun5 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, china 2. china University of Geosciences, Beijing 100083. china 3. Beijing Normal University, Beijing 100875, china 4. Bureau of Hydrology of yellow river conservancy commission, zhengzhou 4.0003, china 5. Bureau of Hydrology and Water Resource Investigation of Qinghai Province, Xining 810001, china 1. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China2. China University of Geosciences 100083 Beijing China3. Beijing Normal University 100875 Beijing China4. Bureau of Hydrology of Yellow River Conservancy Commission 450003 Zhengzhou China5. Bureau of Hydrology and Water Resource Investigation of Qinghai Province 810001 Xining China

The water cycle in the source region of the yellow river underwent great changes in the 1990s. The major features of the changes are as follows: the gauged runoff declined significantly while the precipitation increased slightly, and the runoff process was more concentrated on the flood season. Water balance analyses indicate that the pondage was kept in the status of negative equilibrium, causing eco-environmental problems. The runoff decrement is due to evaporation increment in this region. Studies show that the runoff process in this region is closely related to that of the other hydrological stations in the upper reaches. When the runoff declines in the source regions, the amount of water also declines in the whole upper reaches of the yellow river, affecting the balance between water demand and supply. Meanwhile changes will take place in the water cycle of the river course system when the eco-environment deteriorates. The trend of water cycle change in the source region is that the runoff will keep declining with the increment of evaporation caused by temperature rise in the northwest of china in the 21st century. But the hydraulic engineering in the source region will help to mitigate the deterioration of local eco-environment system, though the impacts to the lower reaches of this project may not be the case.

关键词： source region of the yellow river, water cycle, evaporation, negative equilibrium.

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EVOLUTIONAL CHARACTERISTICS OF HYPER－CONCENTRATED FLOW IN BRAIDED CHANNEL OF THE yellow river

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International Journal of Sediment Research 1996年第3期 49-57页

作者： QI Pu LI Wenxue( Institute of Hydraulic Research,yellow river conservancy {3.,zhengzhou 4.0003,P.R.china)( Chief Engineer,yellow river conservancy {3.,zhengzhou 4.0003,P.R.china)

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ＥＶＯＬＵＴＩＯＮＡＬＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＨＹＰＥＲ－ＣＯＮＣＥＮＴＲＡＴＥＤＦＬＯＷＩＮＢＲＡＩＤＥＤＣＨＡＮＮＥＬＯＦＴＨＥＹＥＬＬＯＷＲＩＶＥＲ￥ＱＩＰｕ；ＬＩＷｅｎｘｕｅ（Ｓｅｎｉｏｒｅｎｇｉｎｅｅｒ，ＩｎｓｔｉｔｕｔｅｏｆＨｙ...

关键词： Hyper-concentrated flood Channel Braided river Hydrograph Sediment concentration Peak flow Flood stage Channel shape

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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.,{3. 4.0003,china 3.North china Institute of Water conservancy and Hydropower,{3. 450008,china 4 china Institute of Water Resources and Hydropower Research,Beijing 10003.,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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Channel Accretion on the Lower Reaches of the yellow river and E

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人民黄河 1985年第3期 7-16页

作者： Research Institute, yellow river conservancy {3. Research Institute yellow river conservancy {3.

Aggradation of channel on the lower reaches of the yellow river is mainly governed by the regimen of river discharge and sediment delivered from upstream. In the long run, channel accretion exhibits alternate increase and decrease, somewhat periodic in *** long-term average annual deposition is something like 3.0 million tons. Besides the aforesaid factor affecting scouring and depositing along the river channel along the lower reaches, there are also the following factors of influence: fluvial processes and changes in river bed in previous stages, operation of Sanmenxia Reservoir in regulating floodwater and sediment delivery, as well as conditions at the river mouth. After undergoing 3.consecutive periods of accretion-degradation-accretion, and being subjected to different measures to cope with the problem at different times, adapting to the actual condition, there is now only accretion to limited extent above Jiahetan and .below Aishan, most of the deposits being laid in the intermedite section. The distribution of the deposits in the crosswise direction is related to overflowing onto the floodplains, the duration, and the condition of levees there (to protect the farmland on the floodplains from ordinary floods). During the period from 1950 to 1983. a total of about 5 biIlion tons of sediment deposited on the floodplains on the lower reaches, comprising 70% of the entire volume of deposition, distributed unevenly though, mainly outside the area sheltered by the levees, effecting in an increase in transverse slope of the channel. In some sections, 'suspended river' was formed within the already 'suspended' river (river bed lying above the land surface behind the dykes).Sequence of years of observation in the fifties was chosen and the regulating effect of the Longyangxia, Liujiaxia and Sanmenxia and other reservoirs is also taken into account. In the 12 years from 1984 to 1995, average annual runoff on the lower reaches of the yellow river will be 3..8

关键词： reaches suspended river yellow somewhat affecting something reservoirs farmland runoff

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AN ANALYSIS OF THE COASTLINE SHIFTING AROUND THE ESTUARY OF THE yellow river

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china Ocean Engineering 1987年第2期 55-66页

作者： Hong Shangchi Wu Zhiyao (Designing Institute, yellow river conservancy {3., zhengzhou)

Based on the observed data, a map of high-tide coastline shifts is made for the area around the estuary of the yellow river, from which the shifting of coastline in the delta area, the land formation through sedimentation, the extension of spits and the coastline retreats are studied. With regard t6 macroscopic aspects, the effect of extension on the lower reaches of the river has been discussed, and some suggestions are presented with respect to the improvement of the area around the yellow river Estuary

关键词： AN ANALYSIS OF THE COASTLINE SHIFTING AROUND THE ESTUARY OF THE yellow river

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SIZE DISTRIBUTIONS OF COARSE SAND BED LOAD IN TURBULENT FLOW FIELD

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Journal of Hydrodynamics 1995年第3期7卷 1-6页

作者： Zhang Hong-wu Wang Shan(Institute of Hydraulic Research yellow river conservancy Commissivn,{3. 4.0003,P.R.china)

Putting forth effort on analyzing the action of turbulent flow on the sand particles on rvier bed surface,in this paper, the interdependent relation between the size distribution of coarse sand bed load and flow stren... 详细信息

关键词： coarse sand bed size distributions turbulent flow

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ON　CALCULATIONS　OF　THE　DRAG　COEFFICIENT　Cd　AND　THE　FALL　VELOCITY　ω　OF　SPHERICAL　BODIES

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Journal of Hydrodynamics 1994年第4期6卷 16-27页

作者： Xiang Zhao-fa (Institute of Estuary and Coastland, yellow river conservancy {3., Jinan, Shandong 250100,P. R. china)

A host of authors have proposed some theoretical and experimental formulas in hydromechanics concerning the calculation of the drag coefficient Cd of spherical bodies. But all of the existing Cd formulas hold true only at small Reynolds numbers and are restricted within certain flowing *** regards the fall velocity ω of spherical bodies, there is yet no formula applicable to each flowing range and to a direct expression and calculation of the fall velocity ω.In view of these, from N-S equations, and meanwhile based on measured data and complicated calculations, the author has developed and proposed the following results:(1) The drag coefficient (2) The dimensionless fall velocity where Es, Ω* and constants etc. are indicated in detail in this *** laborious calculation in lgRe3. preferable on the part of the precision and ***, to introduce this process and to illustrate the temperature effects on the fall velocity ω, some examples are discussed in this paper.

关键词： drag coefficient fall velocity spherical body numerical calculated formula.

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REGULATION OF FLOW AND SEDIMENT LOAD IN THE yellow river

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International Journal of Sediment Research 2007年第2期22卷 103-113页

作者： Wenxue LI1, Jixiang LIU1 and Zhanwei WAN2yellow river Engineering Consulting Co. Ltd., zhengzhou 4.0003,{3.,yellow river Engineering Consulting Co. Ltd., zhengzhou 4.0003,{3. yellow river Engn Consulting Co Ltd Zhengzhou 450003 Peoples R China

Small runoff, large sediment load, and incompatible relationship of flow and sediment load are very important characteristics of the yellow river. They are also the crux of the most prominent problems of the yellow river. To solve these problems, the regimes of flow and sediment load have to be improved by increasing water, reducing sediment load, and by using reservoirs to regulate flow and sediment load. The results of experiments for regulating the flow and sediment load in the last three years by the Xiaolangdi Reservoir have indicated that this measure is a realistic and effective way to mitigate the prominent problems in flood control of the Lower yellow river at present and in the near future. However, the regulation system is still imperfect. It is advisable to speed up the pace of research and construction of the system for regulating flow and sediment load.

关键词： The yellow river Regulation of flow and sediment load The Xiaolangdi Reservoir Experiment Channel deterioration

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DEFORMATION OF river BED AND THE CHARACTERISTICS OF SEDIMENT TRANSPORT DURING HYPER-CONCENTRATED FLOOD IN THE yellow river

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International Journal of Sediment Research 1997年第3期 72-79页

作者： Wenxue LI Senior engineer, Institute of Hydraulic Research, yellow river conservancy {3., zhengzhou 4.0003, china PU QI Senior engineer. Institute of Hydraulic Research, yellow river conservancy {3., zhengzhou 4.0003, china Zanying SUN E

Analysis of field data indicated that channel resistant force during hyper-concentrated flood can be computed by Manning’s equation. The dominant factor which controls sediment transport is the channel configuration. Sediment transporting capacity in narrow and deep channel is potentially large. The suitable sediment concentration for transporting ranges from 3.0 kg/m3.to 800 kg/m3.and the most difficult situation occurs at 200 kg/m3. When hyperconcentrated flood transports through wide and shallow river, the main channel of the river becomes deeper and narrower due to deposition on flood plain and erosion in the channel. Thus, sediment carring capacity increases and so does the speed of flood propagation.

关键词： Hyper-concentrated flood Sediment transport the yellow river

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