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Large-eddy simulation of formation of three-dimensional aeolian sand ripples in a turbulent field

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Science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 945-960页

作者： WU ChuiJie1,WANG Ming2 & WANG Liang3 1 State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian University of Technology,Dalian 116024,china 2 yellow river institute of hydraulic research,zhengzhou 450003,china 3 research Center for Fluid Dynamics,Science School,PLA University of Science and Technology,Nanjing 211101,china State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China yellow river institute of hydraulic research Zhengzhou 450003 China research Center for Fluid Dynamics Science School PLA University of Science and Technology Nanjing 211101 China

With the method of large-eddy simulation,the equation of spherule motion and the method of immersed boundary condition,numerical simulations of three-dimen-sional turbulent aeolian motion and the formation of sand ripples under three-di-mensional turbulent wind and the mutual actions of saltation and creeping motion were carried out. The resulting sand ripples have the form that is flat on the upwind side and steep on the leeward,which is identical to the sand ripples in nature. We also realized the self-restoration process of three-dimensional sand ripples,which shows the correctness of the method of numerical simulation and the models of saltation and creeping. Finally,We analyzed the influence of sand ripples on the three-dimensional turbulent wind field,and found that due to the appearance and development of sand ripples,in the normal direction of ground there exists stronger energy exchange,and moreover,there is close correspondence between the forms of sand ripples and the vorticity close to the ground surface.

关键词： large-eddy simulation equation of spherule motion sand ripples saltation creep

Sediment retention by check dams in the Hekouzhen-Longmen Section of the yellow river

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International Journal of Sediment research 2008年第2期23卷 159-166页

作者： Da-Chuan RAN1,2,Quan-Hua LUO3,Zu-Hao ZHOU4,Guo-Qing WANG5,and Xiao-Hua ZHANG2 1 Senior Engineer,Xi’an University of Technology,Xi’an 710048,china 2 Senior Engineer,yellow river institute of hydraulic research,zhengzhou 450003,china 3 Engineer ,Xifeng Soil and Water Conservation Experimental Station,Qingyang 745000,china 4 Senior Engineer,china institute of Water Resources and Hydropower research,Beijing 100038,china 5 Senior Engineer,Flood prevention office of YRCC,zhengzhou 450003,china [a]Senior Engineer Xi'an University of Technology Xi'an 710048 china [b]Senior Engineer yellow river institute of hydraulic research zhengzhou 450003 china [c]Engineer Xifeng Soil and Water Conservation Experimental Station Qingyang 745000 china [d]Senior Engineer china institute of Water Resources and Hydropower research Beijing 100038 china [e]Senior Engineer Flood prevention office of YRCC zhengzhou 450003 china

Coarse sediment retention by check dams is analyzed for five typical catchments in the Hekou-Longmen section of the midstream of the yellow river,which is an area of high coarse sediment *** catchments are the Huangfuchuan,Kuye,Wuding,Sanchuan and Qiushui river *** amount of coarse sediment retained by check dams in these areas for different periods was *** reduction due to check dams is compared with other soil conservation measures and the results show that check dams are the most effective to rapidly reduce the amount of coarse sediment entering the yellow *** the average percentage of the drainage area with check dams for the five typical catchments reaches 3.0%,the average sediment reduction ratio can reach 60%.Therefore,to rapidly and effectively reduce the amount of sediment,especially coarse sediment,entering the yellow river,the area percentage of check dams in the Hekou-Longmen section should be kept around 3%.The Kuye and Huangfuchuan river Basins are the preferred main catchments in which such water conservation measures are implemented.

关键词： Sediment retention yellow river Check dam Coarse sediment Grain size

TWO-DIMENSIONAL SEDIMENT MATHEMATICAL MODEL FORUNSTEADY FLOW IN THE LOWER yellow river

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International Journal of Sediment research 1999年第2期14卷 295-301页

作者： ZHANG Hongwu LI Dongfeng XU Yuxin ZHANG Junhua (1 Project (No. 39890200) Supported by the National Nature Science Foundation Commission and the Ministry of Water Conservancy 2 yellow river institute of hydraulic research, zhengzhou 450003, china 3 Ye

The theoretical frame of a new two-dimensional sediment mathematical model is established on the basis of the resent research achievements about the sediment transport law of the yellow river. The formulas of sediment carrying capacity of flow and river roughness, which reflect the features of the yellow river, are applied to it. The finite element scheme is employed to deduce the discretized equations of the model. The pre-estimated-verified substitution is used to solve them. Verifications of the model are carried out with the flood occurring on Jinan reach of the yellow river during the flood season in 1976. The calculation results with the model are in good agreement with the measured data.

关键词： Two-dimensional sediment mathematical model the yellow river Model verification

THE OPERATION MODE OF “STORING THECLEAR WATER AND DISCHARGING THE MUDDY FLOW” FOR RESERVOIRS BUILT ON HEAVILY SILT-LADEN riverS——A CASE STUDY OF THE SANMENXIA RESERVOIR

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International Journal of Sediment research 2005年第2期20卷 109-116页

作者： Wenxue LI1,Yuanfeng ZHANG2 and Cuiping ZHANG21 Senior Engineer,yellow river Engineering Consulting Co.Ltd.,zhengzhou 450003,china,2 Senior Engineer,yellow river institute of hydraulic research,zhengzhou 450003,china yellow river Engineering Consulting Co. Ltd. Zhengzhou 450003 China yellow river institute of hydraulic research Zhengzhou 450003 China

Observation of the operation of the Sanmenxia Reservoir on the yellow river has led to the conclusion that to preserve a certain effective storage volume for reservoirs built on heavily silt-laden rivers is feasible if the reservoir is operated according to the principle known as “storing the clear water and discharging the muddy flow”. The relative stability of the bed elevation at the end of the backwater and the reservoir’s erosion and deposition equilibrium depend on the compatibility of the pool level maintained in non-flood seasons with the conditions of flow and sediment load during flood seasons. Operating the reservoir to regulate the flood and sediment load during flood seasons can reduce the rate of aggradation in the Lower yellow river. The basic condition for applying the operation mode of “storing the clear water and discharging the muddy flow” is that a sufficient amount of water should be used for discharging sediment during flood seasons. Under the condition of extremely low flow years,reservoir sedimentation cannot be avoided even if this operation mode is adopted.

关键词： Reservoir Sedimentation The yellow river Operation

A MATHEMATICAL MODEL FOR UNSTEADY SEDIMENT TRANSPORT IN THE LOWER yellow river

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International Journal of Sediment research 2001年第2期16卷 150-158页

作者： ZHANG Hongwu1, HUANG Yuandong1 and ZHAO Lianjun2 1 Department of hydraulic Engineering, Tsinghua University, Beijing 100084, china 2 yellow river institute of hydraulic research, zhengzhou 450003, china Department of hydraulic Engineering Tsinghua University Beijing 100084 China yellow river institute of hydraulic research Zhengzhou 450003 China

A one-dimensional mathematical model for unsteady sediment transport in the Lower yellow river is developed. A coefficient of sediment distribution is defined to represent the ratio of the bottom to the average concentration under the equilibrium conditions. The coefficient is not constant and is evaluated by using an empirical expression obtained by integrating the sediment concentration along water depth. The concentration distributions and the mean diameter distributions of suspended sediment in the transversal direction are also estimated in this model. A four-point (Preismann type) finite difference scheme and TDMA are employed in the numerical method. Three typical floods occurd in 1977,1982 and 1996, respectively, in the Lower yellow river from Tiexie to Shunkou with a length of 393.67km are numerically simulated with the model. The computed results, such as the water stage, discharge, and sediment concentration agree well with the measured data.

关键词： Mathematical model Unsteady sediment transport The Lower yellow river Floods

Runoff reduction due to environmental changes in the Sanchuanhe river basin

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International Journal of Sediment research 2008年第2期23卷 174-180页

作者： Guoqing WANG1,Jianyun ZHANG2,Ruimin HE3,Naiqian JIANG4,and Xin'ai JING5 1 Senior Engineer,State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering,Nanjing hydraulic research institute,Nanjing 210098,china research Center for Climate Change,MWR,Nanjing 210029,china yellow river institute of hydraulic research,zhengzhou 450003,china 2 Prof.,3 Engineer,State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering,Nanjing hydraulic research institute,Nanjing 210098,china 4 Prof.,5 Engineer,yellow river institute of hydraulic research,zhengzhou 450003,china [a]Senior Engineer State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Nanjing hydraulic research institute Nanjing 210098 china research Center for Climate Change MWR Nanjing 210029 china yellow river institute of hydraulic research zhengzhou 450003 china [b]Prof. State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Nanjing hydraulic research institute Nanjing 210098 china [c]Engineer State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Nanjing hydraulic research institute Nanjing 210098 china [d]Prof. yellow river institute of hydraulic research zhengzhou 450003 china [e]Engineer yellow river institute of hydraulic research zhengzhou 450003 china

Recently,runoff in many river basins in china has been ***,the role that climate change and human activities are playing in this decrease is currently of *** this study,we evaluated an assessment method that was designed to quantitatively separate the effects of climate change and human activities on runoff in river ***,we calibrated the SIMHYD rainfall runoff model using naturally recorded hydro-meteorologic data pertaining to the Sanchuanhe river basin and then determined the effects of climate change and human activities on runoff by comparing the estimated natural runoff that occurred during the period in which humans disturbed the basin to the runoff that occurred during the period prior to disturbance by *** results of this study revealed that the SIMHYD rainfall runoff model performs well for estimating monthly *** addition,we found that absolute runoff reductions have increased in response to human activities and climate change,with average reductions of 70.1% and 29.9% in total runoff being caused by human activities and climate change,*** together,the results of this study indicate that human activities are the primary cause of runoff reduction in the Sanchuanhe river basin.

关键词： Sanchuanhe river Hydrological simulation Climate change Human activities Impact

Risk analysis model for landslide mass of high slope in dam area

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Science china(Technological Sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2,HE XianFeng3,4,WU ZhongRu1,2 & SU HuaiZhi1,2 1 College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,china 2 National Engineering research Center of Water Resources Efficient Utilization and Engineering Safety,Nanjing 210098,china 3 yellow river institute of hydraulic research,zhengzhou 450003,china 4 Embankment Security Defect Prevention and Control Engineering research Center of MWR,zhengzhou 450003,china 1. College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China 2. National Engineering research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing 210098 China 3. yellow river institute of hydraulic research Zhengzhou 450003 China 4. Embankment Security Defect Prevention and Control Engineering research Center of MWR Zhengzhou 450003 China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

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,zhengzhou 450003,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

On the variation of water resource structure in the Lower yellow river

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Science china(Technological Sciences) 2004年第z1期47卷 127-141页

作者： NI Jinren1, WANG Yudong1, QIAN Zhenghan1, LI Tianhong1 & ZHAO Yean2 1. Department of Environmental Engineering, Peking University The Key Laboratory of Water and Sedi- ment Sciences, Ministry of Education, Beijing 100871, china 2. institute of hydraulic research, yellow river Conservancy Commission, zhengzhou 450003, china 1. Department of Environmental Engineering Peking University 100871 Beijing China2. The Key Laboratory of Water and Sediment Sciences Ministry of Education 100871 Beijing China3. Institute of Hydraulic Research YellowRiver Conservancy Commission 450003 Zhengzhou China

In view of river functions and the Minimum Water Demand for river Ecosystem (MWDRE), the water resources in the Lower yellow river is further divided into three portions, i.e. water available for ecosystem (WE), water exploitable for socioeconomic purposes (WS) and excess flood water (WF). Corresponding conceptions and practical significances are expounded in details. The annual amount of the three portions of water resources from 1950 to 2001 is worked out on the basis of the daily hydrologic data, and the division of different portions is discussed. The results indicate that although the essential water demand for river functions is considered preferentially, the amount of the WE has decreased dramatically while its proportion increased gradually since the 1950s, and the shortage to the MWDRE increased markedly; both the amount and the proportion of the WS decreased notably. Since the 1990s, the actual water consumption for socioeconomic purposes in the lower reaches of the river basin has already exceeded the maximum amount of the WS and has to take over the WE which is already insufficient, hence not only the normal river functions are further disturbed and the river course shrinks greatly, but also the proportion and potential danger of the WF show no decreasing tendency in spite of the sharp decrease of upstream runoff.

关键词： the yellow river, water resource structure, water available for ecosystem, water exploitable for socioeconomic purposes, excess flood water.