ON THE INFLUENCE OF TURBULENCE ON THE INITIATION OF SEDIMENT MOTION

1 PROBLEM DEFINITION Owing to the practical importance of the initiation of motion many researchers began to tackle this problem even at the beginning of the last century (e.g. Kramer (1932, 1935), Casey (1935)). Shields (1936, Fig. 1) developed a non-dimensional representation based on the measured data of Casey, Kramer, USWES and Gilbert, together with his own data based on investigations with succinite sand, lignite, granite chips and heavy spar. Despite the different material p…     

REPORT ON THE ACTIVITIES OF THE INTERNATIONAL COMMISSION ON SNOW AND ICE FOR THE PERIOD 1971–1975

ABSTRACT

An infiltration model based on the Green-Ampt assumptions is developed for a class of non-uniform soils in which saturated hydraulic conductivity decreases as an exponential function of depth, and the storage-suction factor C = ΔθΔΨ is a constant. An analysis of measured hydraulic conductivity and porosity data suggests that the model may be useful in some soils where the changes of hydraulic characteristics with depth are of this form. A method for using the model with time variable rainfall rates is given. The model is applied to simulate the experimental results of Childs &; Bybordi (1969) who measured infiltration into layered sand profiles. Agreement was satisfactory even for this case.     

BRIEF REPORT ON THE SYMPOSIUM ON TANCHENG-LUJIANG FAULT ZONE

The Symposium on Tancheng-Lujiang fault zone held at Weifang, Shandong province on November 1-10, 1980 was organized by the Geological Society of China, accompanied with field trip. The problems of the regional geological investigations, exploratory survey for ores, geophysical prospecting, seismogeology and images interpretation have been thoroughly discussed.All representatives came to following common understanding: (1)Tancheng-Lujiang fault zone is a gigantic fault zone in East Chi     

ON THE THEORIES OF HYDRAULIC GEOMETRY

Hydraulic geometry is of fundamental importance in planning, design, and management of river engineering and training works. Although some concepts of hydraulic geometry were proposed toward the end of the nineteenth century, the real impetus toward formulating a theory of hydraulic geometry was provided by the work of Leopold and Maddock (1953). A number of theories have since been proposed. Some of the theories are interrelated but others are based on quite different principles. All theories, however, assume that the river flow is steady and uniform and the river tends to attain a state of equilibrium or quasi-equilibrium. The differences are due to the differences in hydraulic mechanisms that the theories employ to explain the attainment of equilibrium by the river.     

ON THE DYNAMIC MECHANISM OFEROSION PROCESS

Erosion process is controlled and affected by various forces of different nature. Erosion processes induced or affected by these forces can be classified into three cate- gories: erosion process induced by endogenic agent, by exogenic agent and associated with human activities. In this article, various dynamic mechanisms are systematically reviewed. Effects of tectonic stress and gravitational stress fields on erosion, effects of human activity on erosion, effect of exogenic forces such as water and wind erosion are discussed respectively.     

ANALYSIS ON THE DEBRIS FLOW SURGES

ＡＮＡＬＹＳＩＳＯＮＴＨＥＤＥＢＲＩＳＦＬＯＷＳＵＲＧＥＳ￥ＷａｎｇＧｕａｎｇｑｉａｎ（Ｐｒｏｆｅｓｓｏｒ，Ｄｅｐｔ．ｏｆＨｙｄｒａｕｌｉｃＥｎｇｉｎｅｅｒｉｎｇ，ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙ）Ａｂｓｔｒａｃｔ：Ｂａｓｅｄｏｎｔｈｅｆｕｎｄａ...     

ANALYSIS ON THE SENSITIVITY OF THE FLUVIAL PROCESS IN ALLUVIAL RIVER

ＡＮＡＬＹＳＩＳＯＮＴＨＥＳＥＮＳＩＴＩＶＩＴＹＯＦＴＨＥＦＬＵＶＩＡＬＰＲＯＣＥＳＳＩＮＡＬＬＵＶＩＡＬＲＩＶＥＲ￥ＣＡＯＷｃｎｈｏｎｇａｎｄＺＨＡＮＧＱｉｓｈｕｎ（ＲｅｓｅａｒｃｈＥｎｇｉｎｅｅｒ，ＩｎｓｔｉｔｕｔｅｏｆＷａｔｅｒＣｏｎｓｅｒｖａ...     

THE EFFECTS OF TURBULENT BURSTING ON THE SEDIMENT MOVEMENT IN SUSPENSION

~~THE EFFECTS OF TURBULENT BURSTING ON THE SEDIMENT MOVEMENT IN SUSPENSION@Ye MAO$Hohai University!Nanjing 210098 China~~     

ON THE DEPOSITIONAL DYNAMICS OF GUANHE ESTUARY

ＯＮＴＨＥＤＥＰＯＳＩＴＩＯＮＡＬＤＹＮＡＭＩＣＳＯＦＧＵＡＮＲＥＥＳＴＵＡＲＹＺＨＡＮＧＤｏｎｇｓｈｅｎｇ；ＺＨＡＮＧＣｈａｎｇｋｕａｎａｎｄＤＩＮＧＸｉａｎｒｏｎｇ（Ｐｒｏｆ．ＨｏｈａｉＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｊｉｎｇ，Ｃｈｉｎａ）（Ａｓｓ，...     

ON THE VARIETY AND COMPLEXITY OF THE SHORT-TERM AND URGENT PRECURSORS OF THE TANGSHAN EARTHQUAKE

The Tangshan earthquake(M=7.8)which occurred on July 28, 1976 is the greatest event among the modern catastrophes in China. It occurred in a region that was the most densely networked with seismic stations, a region that had the longest history in seismological work and had received     

INFLUENCE OF THE UPSTREAM RESERVOIRS ON THE ADJUSTMENT OF DOWNSTREAM ALLUVIAL CHANNEL

I. INTRODUCTIONThe Yellow River is a heavily sediment--laden river. The sediment load of the Yellow River ranks the first in the world while its annual runoff is only of medium size. Toharness the river, it is necessary to build reservoirs for regulating runoff to meet the demands of economic development. Since the founding of PRC in 1949, I S4 large and medium--sized reservoirs have been constructed on the main stem and the tributaries with atotal storage capacity of 84.5 billion m3.…     

A STUDY ON THE EQUILIBRIUM PROFILE FOR THE LUOSHAN-HANKOU REACH IN THE MIDDLE YANGTZE RIVER

1 INTRODUCTION Large-scale flood disasters have frequently occurred in the middle Yangtze River since the 1990抯. The Jingjiang River and Dongting Lake (Fig. 1) comprise the most serious area of flood disasters. The main characteristic of recent disasters is low discharge and high water stage. Recent research has begun to pay more attention to the important role of sediment deposition (Li and Ni, 1998). Though the Yangtze River is not an overloaded river, the amount of sediment trans…     

EFFECT OF DIVERSION ON THE LOWER YELLOW RIVER

ＥＦＦＥＣＴＯＦＤＩＶＥＲＳＩＯＮＯＮＴＨＥＬＯＷＥＲＹＥＬＬＯＷＲＩＶＥＲ￥ＷａｎｇＹａｎ－ｇｕｉａｎｄＬｉＸｉ－ｘｉａ（Ｅｎｇｉｎｅｅｒ，ＳｅｄｉｍｅｎｔＤｅｐｔｏｆＩｎｓｔｉｔｕｔｅｏｆＷａｔｅｒＣｏｎｓｅｒｖａｎｃｙａｎｄＨｙｄｒｏｅｌｃｔｒ...     

ON THE VERTICAL DISTRIBUTION OF SUSPENDED SEDIMENT CONCENTRATION

The problem of sediment concentration distribution in a vertical for channel and pipe flows is studied in this paper. Considering the variation of the vertical component of the fluctuation velocity v as an independent variable, two types of sediment concentration distribution can be derived. However, only one type of distribution is commonly quoted while the other one rarely reported. In this paper explanation for such phenomena is given and conditions for the occurrence of both types are also discussed.     

AN EXPERIMENTAL STUDY ON SEDIMENT FLUSHING OF DONGZHUANG RESERVOIR ON THE JINGHE RIVER

~~AN EXPERIMENTAL STUDY ON SEDIMENT FLUSHING OF DONGZHUANG RESERVOIR ON THE JINGHE RIVER@Hongwu ZHANG$Department of Hydraulic Engineering,Tsinghua University!Beijing100084 @Ouyang ZHANG$Department of Hydraulic Engineering,Tsinghua University!Beijing100084 @Junhua ZHANG$Institute of Hydraulic Research of Yellow River Conservation Commission!zhengzhou 450003 @Guodong WANG$Institute of Hydraulic Research of Yellow River Conservation Comm…     

ON THE PHYSICS OF FLOW-DRIVEN SEDIMENTS (BED-LOAD)

l PROBLEMS AND AlMSSediments may be transported close to the bed, rolling and sliding, as we1l as susPended in the flow. Forvarious reasons the theoretical treatment of the bed-load problem has been exceptionally difficult. Noanalytical solution had been fOund uP to now, beginning with Du Buat (l786), Huebbe (l86l) and DuBoys (I 879). Since the aPProach of Du Boys numerous new attemPts have been catried out, mostly of anempirical nature. Consequently they are not generally valid an…     

THEORETICAL ANALYSIS ON THE VERTICAL DISTRIBUTION OF PARTICLE CONCENTRATION

1 wrRonvCTIoxIn steady solid-liquid tuIbulen flows, tWo twcal pattems of particle concentration distribuhon, namelypattem I and pattem II, have been found by man investigatOI'S (e.g. Bouvard & Petkovic l985, Wang &Ni l990), as shown in Fig.l. Genend sPeaking, pattem II is conunn, and most inveshgators fOcused theirefforts on this pattem. Vedous theories such as the diffesion theory, the ndxtUre theory, the enery theory,the sindlarity theory and the stochashc theory among others have co…     

FIELD STUDY ON WIND EROSION IN THE NORTHWESTSHANXI PROVINCE

Field study on wind erosion in the hilly regions with gentle slope in the Northwest Shanxi Province has been carried out from 1983 through 1988. Based on the data observed in the field, quantitative analyses of the wind erosion and the effects of the wind-break forest are presented in this paper in detail. Most of the strong windy days occur in the period of March to May. The coincidence of drought and strong wind in the Spring days with no vegetative cover at all on the loose top soil lead to severe wind erosion in this region. The rate of soil erosion is as high as 12800 t / km2. Major characteristics of wind and other meteorological factors are given in graphs and tables. Wind-break forest reduces the wind velocity by 51. 1 %. Consequently, the amount of wind erosion is reduced by 90% and the dust content in the atmosphere is reduced by 97. 1 % in comparison with those measured in the farmland. This paper provides a preliminary summary on the result of data analyses of wind erosion on the Loess Plateau. It can serve as scientific basis for control of the wind erosion in regions of similar conditions.     

MORPHOLOGIC EQUATIONS BASED ON THE PRINCIPLE OF MAXIMUM ENTROPY

ＭＯＲＰＨＯＬＯＧＩＣＥＱＵＡＴＩＯＮＳＢＡＳＥＤＯＮＴＨＥＰＲＩＮＣＩＰＬＥＯＦＭＡＸＩＭＵＭＥＮＴＲＯＰＹＤＥＮＧＺｈｉｑｉａｎｇ；ＺＨＡＮＧＫａｉｑｕａｎＡｂｓｔｒａｃｔ：Ｔｈｅｐｒｉｎｃｉｐｌｅｏｆｍａｘｉｍｕｍｅｎｔｒｏｐｙｉｓｕｓｅｄｔｏ...