CHANNEL WIDENING DURING DEGRADATION OF ALLUVIAL RIVER

1 INTRODUCTIONThe fluvial processes such as transihon of river pattrms, bank chat and advance, sedimentation anderosion of flood plains and channel beds can be Observed in alluvial rivers. These fluvial PrOcesses are allattributed to variations of the sediment caping caPacity of the flow and the erodibillty of bank matrialor soil. A river sechon may be widened by bank erosion and failure.For examPle, a river channel downstream of a reservoir is scoured because the flow released frOm the…     

THE FORMING CONDITIONS OF ALLUVIAL RIVER CHANNEL PATTERNS

1 INTRODUCTION It is well known that the river channel patterns are determined by long-term water-sediment conditions. However, quantitative expressions for river channel patterns and their fluvial processes still remain not clear. Existing theories in this aspects, such as geomophological theory, theory of maximum energy consuming rate, stability theory, theory of probability, and statistic analysis, are developed based on certain simplified assumptions and can not be successfully used t…     

A NON-DIMENSIONAL COUPLED NUMERICAL MODEL OF ALLUVIAL FLOW

ＡＮＯＮ－ＤＩＭＥＮＳＩＯＮＡＬＣＯＵＰＬＥＤＮＵＭＥＲＩＣＡＬＭＯＤＥＬＯＦＡＬＬＵＶＩＡＬＦＬＯＷＳａｉｅｄＳＡＩＥＤＩ（ＴｈｅｔｅｘｔｉｓａｂｒｉｄｇｅｄｂｙＤｒ．ＤＩＮＧＬｉａｎｚｈｅｎ）（ＷａｔｅｒＲｅｓｅａｒｃｈＬａｂｏｒａｔｏｒｙ，Ｓｃ...     

FORECASTING IMPACTS OF HYDRAULIC STRUCTURESON AN ALLUVIAL RIVER

In the last decades the construction of large hydraulic projects on alluvial rivers in China has spurred the development of both physical and one-dimensional mathematical modeling to the point that deposition and erosion predicted by modeling in either way conform to prototype observations over periods of 3 to 19 years. The prototype data are those of Gezhouba on the Yangtze River and Danjiangkou on the Han River. The accuracy attained is in the neighborhood of 20% which is considered good enough in sedimentation engineering. Thus these techniques of modeling may be applied to forecast the impacts of hydraulic structures on an alluvial river. Mathematical modeling in 2 space variables has also been developed, but still awaits further verification.     

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.…     

APPLICABILITY OF THE BEND DEVELOPMENT THEORY IN NATURAL ALLUVIAL RIVERS

1 INTRODUCTION Meanders are the fundamental planform of alluvial rivers and bank erosion in the meander bends is a common feature. In most of the practical cases, the eroded material from the outer bank deposits along the inner bank to develop sand bars. Very often, bank erosion is drastic and channel width increases in an order of several hundred meter per year at some reaches of large scale meandering rivers, for example, the Ganges river inside Bangladesh, as noticed by Muramoto and…     

NUMERICAL SIMULATION OF SEDIMENT TRANSPORT IN ALLUVIAL RIVER WITH FLOODPLAINS

1 INTRODUCTION The transport of sediment in rivers with active floodplains is a two-dimensional process because the main channel and the floodplain can have very different transport capacities. Therefore, two-dimensional (2D) models are often used to simulate the streamwise and transverse variations of sediment erosion and deposition. Many 2D numerical models have been presented to simulate sediment transport in floodplains (James, 1985; Pizzuto, 1987; Howard, 1992; Nicholas and Walli…     

NUMERICAL MODELING OF TURBID FLOOD ROUTING IN AN ALLUVIAL RIVER

1.INTRODUCTIONWeusedequationsgoverningt1Vo-phaseflowtotisedcalculateturbidunsteadyflowinanalluvialriver.Thegeneralcurvilinearbody-fittedcoordinateisintheirregUlardomain,andthenon-uniformparticlesforsuspendedandbedload.Themixingdensityisp=pl(l-C)+P=C,wherepl.f>2Isthedensityofwaterandsedimentrespectively,andCistheconcentrationbyvolume.Thevelocityoffluidmixtureisdefinedinthemomentumequationby;pul=al(l-C)xl,,+pZCwl,Thesedimenttransportcapacity'S*.G*,theprobabilityofmotioninfalling,thesus…     

ANALYSIS ON THE SENSITIVITY OF THE FLUVIAL PROCESS IN ALLUVIAL RIVER

ＡＮＡＬＹＳＩＳＯＮＴＨＥＳＥＮＳＩＴＩＶＩＴＹＯＦＴＨＥＦＬＵＶＩＡＬＰＲＯＣＥＳＳＩＮＡＬＬＵＶＩＡＬＲＩＶＥＲ￥ＣＡＯＷｃｎｈｏｎｇａｎｄＺＨＡＮＧＱｉｓｈｕｎ（ＲｅｓｅａｒｃｈＥｎｇｉｎｅｅｒ，ＩｎｓｔｉｔｕｔｅｏｆＷａｔｅｒＣｏｎｓｅｒｖａ...     

DAM IMPACTS ON AND RESTORATION OF AN ALLUVIAL RIVER-RIO GRANDE, NEW MEXICO

1 INTRODUCTION The construction of more than 75,000 dams and reservoirs on rivers in the United States (Graf, 1999) has resulted in alteration of the hydrology, geometry, and sediment flow in many of the river channels downstream of dams. Additionally, hydrologic and geomorphic impacts lead to changes in the physical habitat affecting both the flora and fauna of the riparian and aquatic environments. Legislation for protection of endangered species as well as heightened interest in ma…     

ON THE SENSITIVITY OF ALLUVIAL FLOW MODELS TO COMPUTATIONAL TIME AND DISTANCE STEPS

ＯＮＴＨＥＳＥＮＳＩＴＩＶＩＴＹＯＦＡＬＬＵＶＩＡＬＦＬＯＷＭＯＤＥＬＳＴＯＣＯＭＰＵＴＡＴＩＯＮＡＬＴＩＭＥＡＮＤＤＩＳＴＡＮＣＥＳＴＥＰＳＳａｉｅｄＳＡＩＥＤＩ（ＷａｔｅｒＲｅｓｅａｒｃｈＬａｂｏｒａｔｏｒｙ，ＳｃｈｏｏｌｏｆＣｉｖｉｌＥｎｇｉｎ...     

STOCIIASTIC DESIGN IN ALLUVIAL RIVERS

ＳＴＯＣＩＩＡＳＴＩＣＤＥＳＩＧＮＩＮＡＬＬＵＶＩＡＬＲＩＶＥＲＳ￥ＷｏｉｆｇｎｇＫｒｏｎ（ＲｅｓｅａｒｃｈＡｓｓｏｃｉａｔｅ，ＧｅｏＦｏｒｓｃｈｕｎｇｓＺｅｎｔｒｕｍ（ｔｈｅＲｅｓｅａｒｃｈＣｅｄｅｒ），１４４７３Ｐｏｔｓｄａｍ，Ｇｅｒｍａｎｙ）Ａ...     

EFFECTS OF RIVER ICE ON STAGE-DISCHARGE RELATIONSHIPS——A CASE STUDY OF THE YELLOW RIVER

Using field observations at four gauging stations along the Inner Mongolia Reach of the Yellow River in China, this paper explores effects of the ice on the hydraulics of this river reach for four different conditions, namely: under open channel flow, during ice-running period, the ice-covered period, and the river break-up period. The rating curves were found to be well recognized under open channel situations, but were sometimes poorly defined and extremely variable under ice conditions. The results also show that the water level is insensitive to flowing ice prior to freeze-up. However, significant, but hardly surprising, variations were observed during ice-covered conditions. The rating curves for both the ice covered condition and river ice breakup period are developed and some related hydraulic issues are examined. Additionally, the impacts of the ice accumulation and associated riverbed deformation during ice period on the rating curves are discussed.     

A QUASI-TWO-DIMENSIONAL STREAM TUBE MODEL FOR SIMULATING FLOW IN ALLUVIAL RIVERS

I. INTRODUCTIONIt is necessary, sometimes, to predict river bed deformahon during the alanning and design stages of a hydraulic project. As the nuvial process is quite complicated, the I --Dmathematical models currently in use can not satisfy the various needs in hydraulic engineering. Particularly in engineering practice, there is a strong desire of knowing the hydraulicconditions and river bed deformation in details. Some two dimensional models as well asqusi--two--dissensional models …     

CRUSTAL MOVEMENT OF THE GREAT LAKES—TIME SERIES ANALYSIS

ABSTRACT

Time series techniques were employed to determine rates of vertical crustal movement within the Great Lakes region of North America. Observations of water level elevations as recorded at gauges around the lakes, and differences in elevations between pairs of gauges were analysed for linear trends, periodicities and stochastic components. It was found that the variance of time series of elevations consisted mainly of first-order linear trends and small periodic components. Relative rates of crustal movement were computed from a linear trends analysis of elevation differences. These rates were converted to absolute rates of movement using the Nipissing zero isobase as a datum.

This study shows that, in general, the northeastern area of the Great Lakes region is rising at a rate of about 1·00 ft per 100 years relative to the southwest of the region.     

TEMPORAL ORDERLINESS OF EARTHQUAKES (M≥8) ON CHINA MAINLAND——A NEW APPROACH TO THE PREDICTION OF EARTHQUAKES

Some great earthquakes of magnitude 8 or greater on China mainland repeatedly occurred at the intervals of 252, 94, 48, and 25 years. It incited us to study the time interval between every pair of great earthquakes (M≥8) on China mainland. The result shows that there are four groups of clear orderliness distinguished in the most disorder distribution of earthquakes. The distinguished orderliness can be used to estimate the occurrence of next great earthquakes in China     

2.—FORECAST OF SUMMER FLOOD WAVES OF THE SIÓ AND KAPOS RIVERS FROM PRECIPITATION

Abstract

Flood forecasts for the Sió and Kapos Rivers in Hungary have been made using gage relations. In order to increase the forecast time advantage procedures have been developed for predicting maximum stage using precipitation data and other variables including soil moisture index.

The paper describes the methods for developing forecasting relations involving three variables and four or more variables. The procedures are restricted to flood events caused by summer and autumn-precipitation (ice and snow-melt floods excluded).     

THE APPLICATION OF PETROLEUM SEISMIC DATA TO THE BURIED ACTIVE FAULT DETECTION——A CASE STUDY OF ACTIVE FAULTS SURVEYING IN SONGYUAN CITY

Located in the south of the Songliao Basin, Songyuan City is one of the few high seismic intensity regions (Ⅷ degree regions) in Northeast China, where a magnitude 6(3/4) earthquake took place in 1119. Since 2013, many earthquakes of magnitude above 5 have occurred in Chaganhua Town which is 100km southwest of Songyuan. The faults in the study region are almost all in a concealed state and covered by the Quaternary system, therefore, geophysical investigation, drilling and other similar means are required to determine their distribution, occurrence, nature and active period. Many seismic explorations in this region aiming at surveying the oil bearing structure have been conducted by Jilin Oilfield, which provides detailed seismic exploration information for preliminary detection of active faults. In this paper, the main features of petroleum-related seismic data and major methods for extracting tectonic information are presented; on the plain, the trace information of the main structure is extracted by the t0 interface contour map which allows direct reflection of rises and falls of stratal interfaces and the tectonic characteristics of the corresponding geologic period; on the section, the "extending upwards" characteristics of faults are captured by tracing and marking geological phenomena in the reflective standard layer, faults, the surface of unconformity and so on. Under the comprehensive use of the "3D" structure in the interpretation of the results, accurate spatial distribution information of main faults are obtained in the study region, this offers an effective approach to preliminary judgment of the activity of faults in this region. Meanwhile, the active age of the target faults is identified by superimposing the deep and shallow seismic data and integrating with the drilling detection.