Blown-Sand Transport Rate

LI Zhen shan^1,3, NI Jin ren^2,3ªª
(1.Department of Hydraulic Engineering, Tsinghua University, Beijing 100084 China;
2. Center for Environmental Science, Peking University,Beijing 100871 China;
3.Key Laboratory for Water and Sediment Sciences, Ministry of Education China)

Abstract: With the thread of two dimensionless parameters, (=gQ/¦ÑU3*) and r(=U*t/U*), systematic analysis was made based on previous measured data and comparison was given for eight representative formulas for aeolian mass flux¡£As a result, a general formulation structure was proposed, from which each of the previous formulas could be reproduced. In addition, all patterns, drawn from the measured results, in terms of ø¡«r relation presenting the blown-sand transport rate were well reflected, including the monotony-increase pattern that was excluded from the existing formulas. Therefore, the good fit of any existing formula to some data but deviate from other data could be explained by the general formula. Four primary parameters should be determined for description ofvarious patterns and existing formulas. Variation of the primary parameters wasalso discussed with the measured data, and the relevance of some parameters to grain size characteristics was presented.

Key words: blown-sand flow; transport rate; formula; grain size

Study on the Evolution of Goose-neck Bifurcated Channel in the
Middle and Lower Reaches of Changjiang(Yangtze) River

MA You-guo¹, GAO You hua²
(1. Wuhan university, Wuhan, Hubei, 430072, P.R.China;
2. Changjiang River Conservancy Commission, Wuhan, Hubei, 430010, P.R.China)

Abstract: The goose-neck bifurcated channel is the one with the most complicated shape, thebiggest broaden-rate and the largest in number in the middle and lower reaches of the Changjiang(Yangtze) river, and its length is almost 40 percent of that of the whole bifurcated channel. The evolution of this kind of channel mainly depends on the morphology of river bed, the boundary conditions and inflow conditions. In this paper the morphology characteristics and the evolution process of the goose-neck bifurcated channel are analyzed based on the data obtained by observation from Chenglingji to Jiangyin in the middle and lower reaches of the Changjiang river. Further more, the cause for the formation of goose-neck bifurcated channel is also investigated. The results of this paper are helpful to the river regulation in engineering practice.

Key words: bifurcated channel; evolution characteristics; goose-neck

Discussion on the Dimensionless Parameters in the Investigation
of Bingham-Fluid Continual and Intermittent Flow

LIU Da-you¹, DUAN Xin-ping¹,ZHANG Shu-cheng², YU Bin²
(1.Institute of Mechanics, Chinese Academy of Sciences;
2.Institute of Mountain Hazards and Environment, Chinese Academy of Sciences)

Abstract: In this paper, the comments about the selection of dimensionless parameters in the investigation of axisymmeteric and 2-D pipe flow and continual open channel flow were given. The advantages of the dimensionless expressions, the diversity of the dimensionless method and the importance of the selection of the basic variables were demonstrated by the above flow which have analytical solution. The proper selection of the basic variables in the investigation of the intermittent flow of Bingham-fluid was discussed at last.

Key words: dimensionless parameters; Bingham-fluid; continual flow;intermittent flow

On the Turbidity Maximum in the Chinese Estuaries

SHEN Huan-ting, HE Song-ling, MAO Zhi-chang, LI Jiu-fa
(State Key Laboratory of Estuarine and Coastal Research East China NormalUniversity
3663 Zhongshan Road (N), Shanghai 200062, China)

Abstract: Most of the Chinese estuaries, such as the Yangtze River, the Yellow River, the Pearl River,the Qiantang River, the Oujiang and the Jiaojiang River estuaries, exhibit strong turbidity maximum. ln this paper, large data sets will be used to provied a comparison of the physical background and characteristics within therespective turbidity maximum regions of those estuaries. Based on sources and convergences of estuarine fine sediments, five different types of the turbidity maximum can be proposed for the Chinese estuaries:¢¡¡£terrigenous-tidal-induced,¢¢¡£terrigenous-saline-induced,¢£¡£terrigenous-tidal-saline composite,¢¤¡£marine-tidal-induced,and ¢¥¡£marine-saline-induced.

Key words: turbidity maximum; fine suspended sediment; Chinese estuaries:Yangtze River,Pearl River, Yellow River and Qiantang River estuaries

Application and Comparison of Fluid-Sediment ANN
Prediction Model with Empirical Model

LI Yi-tian^£±, LI Rong², HUANG Wei²
(1. Wuhan University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education;
Wuhan, 430072)(2. Pudong Bureau of Water Resources, Shanghai, 201200)

Abstract: Flood evolvement exhibits a complicated non-linear dynamical process. Seeing that artificial neural network possesses the capabilities of dealing with complex non-linear dynamical systems, this paper demonstrates how it can be used inflood prediction as a new approach by considering the non-linear relationship between flood evolvement and its affecting factors. Comparing of fluid-sedimentANN(Artificial Neural Network) prediction model with empirical model is made and two models are applied to the flood level prediction of Yangtze River at Luoshan station.

Kdy words: artificial neural network; empirical model; comparing; sediment disaster

Research on the Mechanism and Control Measuresof
Dike Pit type Slide in the Yangtze River

JIN La hua¹, SHI Xiu qing¹, WANG Nan hai²
(1. Department of Environmental Engineering, Nanchang University,339 Beijing East Road, Nanchang,330029,P.R.China;2.Institute of Water Conservancy Research of Jiangxi Province,386 Beijing East Road, Nanchang, 330029, P. R. China)

A Study on Utilizing Ultrasonic for Sediment Measurement

LIU Min
(Guangdong Provincial Research Institute of Water Conservancy & Hydropower)

Abstract: This paper presents a new method of measurement of sediment utilizing ultrasonic theory and eletronic gain compensation technique. A lot of test in laboratory and field provided that this measurement technique is easy to realize and to operate.

Key words: ultrasonic waves; gain compensation; method of sediment measurement

Experimental Study on the "W" Scheme for Improving the Navigation Conditionin the Gezhouba Project Navigation Channel Downstream of the No.1 Ship-lock Using Ship Model

LI Xian-zhong¹, ZHAO Lian-bai², LI Yi-bing²
(1.Ministry of Communications. Tsinghua University; 2.The Tianjin Institute of Water Way Transportation Research)

Abstract: The "W"scheme put forward by the Yangtze River Committee is designed to improve the navigation condition in the Gezhouba Project navigation channel¡¡downstream of the No.1 ship-lock. A series of experiments are conductedto test the effectiveness of this scheme and its impact on the movement of barges. With the development of the Three-Gorges Project, the water level at Yichang gauge station will be further reduced. This study shows that engineering measure to improve navigation condition is necessary. The ship model tests indicatethat 6000T fleet can pass through the No.1 Ship-lock under discharge of 35000m³/s.

Key words: the Gezhouba Project navigation channel downstream of theNo.1 ship lock; engineering measure; reduction of water level; ship model

A Mathematical Model on the Armoring of River Bed Downstream ReservoirMAO

Ji-xinHAN Qi-wei
(China institute of Water Resource and hydropower Research,
P.O.Box 366,Beijing 100044,China)

Abstract: Based on the theoretical equation about incipient velocity and coarsening of sediment, a mathematical model on the armoring of river bed is put forward, it is simple and direct to study the maximum erosion thickness and sediment composition in armored layer, according to the illustration analysis, compared with the 1-D model result, and the with measured data, it is shown that the maximum erosion thickness and the sediment grading in armored layer calculated by this model are rational and reliable.

Key words: river bed; coarsening; maximum erosion thickness; mathematical model

Study on Waterway Regulation of the Reach from
Shantang to Shijiao on the Beijiang River

XIE Ling-feng¹,LU Yong-jun²,WANG Yi-an³,LU Huan-cai³,CHENG Jian¹
(1.Guangdong Waterway Survey Design Research Institute;2.NanjinHydraulic Research Institute£»
3.Tianjin Institute of Water Transport Engineering)

Abstract: The high density,long shallow,many channels and complicated shoal types are the characteristics of the shoal reach from Shantang to Shijiao on the Beijiang River channel.The hydrology,the sedimentation and the river bed deformation are affected by many-sided factors.The selection of the channels and the optimal training works has much difficulties.Based on the field data and the physical model results,the cause of formation for every shoal was anal yzed in this paper,and the principles and the methods of regulation were put forward.

Key words: Beijiang River; shoals; cause of formation; waterways; regulation

Uncertainties of Amount of Sedimentation Evaluated by Sediment Balance Equation £­for Yellow River Reaches between Lanzhou and Huayuankou

CHENG Long-yuan¹,GONG Zeng-xi², HE Rui-li²,LI Jing², SONG Hai-song²
(1.Bureau of Hydrology and Water Resources of Sanmenxia Reservoir Area;
2.The Hydrology Bureau of Yellow River£©

Abstract:The following three aspects were discussed in this paper: 1.The equivalent thickness of the amount of deposition or erosion in the main channel was analyzed for reaches below Lanzhou where no sedimentation survey data are available; 2.For reaches where amount of deposition or erosion can be obtained directly fromsystematic sedimentation survey data, sediment balance equation can be used to evaluate the composite error. The amount of deposition or erosion would involve largely the composite error if it were estimated by means of the sediment balance equation. 3. For reaches where no surveying data are available, thickness of the amount of deposition or erosion is estimated by sediment balance equation andalso by the variation of water level under same discharge. Comparisons were made with the amount of deposition or erosion computed by different people for periods from 1959 to 1989 in different research projects. It is concluded that the amount of sedimentation obtained by means of the sediment balance equation can not reflect the actual status of river sedimentation.

Key words: water level under the same discharge; shoals and rapids; chickness of deposition or erosion; river reach between Lanzhou and Huayuankou; composite error