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  • A field experiment on the development of sedimentary structures in a gravel-bed river
  • Canada ; Experimentation ; Gravel ; Quebec ; River bed ; Sediment transport ; Sedimentary structure ; Spatial distribution ; Stream
  • This paper aims to improve the understanding of the dynamics of sedimentary structures at the reach scale using a field approach. The AA. investigated the dynamics of sedimentary structures in three 15 m long reaches of a small gravel-bed river
  • , (Moras Creek, Québec), characterized by moderate slope and high relative roughness. The results show that the rapid adjustment of the bed is associated with the development of key sedimentary structures anchored by the large boulders. At the reach scale
  • , these structures increased the probability of congested areas in the displacement of bed material. In both control sections, sedimentary structures were maintained during the experiment.
  • Thresholds of particle entrainment in a poorly sorted sandy gravel-bed river
  • This paper presents an analysis of a new data set on threshold conditions for bed material entrainment in the poorly sorted sandy gravel-bed of the Arbúcies River (NE Spain), an interesting example of a perennial to ephemeral transitional
  • Patterns and processes of sediment sorting in gravel-bed rivers
  • After a brief description of the principal sedimentological features of gravel-bed rivers, this article reviews the mechanisms that sort bed material by size during sediment entrainment, transport and deposition and discusses some of the inter
  • Suspended and bed material load in Norwegian rivers
  • Modelling the impact of anthropogenic modifications to river channels on the course of extreme floods
  • Czech Republic ; Flood ; Human impact ; Impact ; Modelling ; River bed
  • in the river bed and in the inundation zone due to river network modifications. The one-dimensional hydraulic model HEC-RAS coupled with GIS is used to simulate the effect of the river channel changes on the course of extreme flood. - (EN)
  • This paper presents the results of analysis of the impact of anthropogenic modifications to river channels on the course of floods by means of hydraulic modeling. The study is focused on the quantitative analysis of changes of the flow dynamics
  • The fluvial process of the lower Yellow River and its extension of river mouth deposits.
  • The old beds of the Yellow River can be found almost everywhere on the North China Plain. The cyclical process of the estuary development, namely, rerouting, extending, and rerouting again, is an epitome of the estuary development in the past
  • but on a big scale now. The extension of the river mouth is the direct cause of aggradation of the river bed above the point of estuary pivot, arising from large sediment load consequent to soil erosion in the upland areas. (TNC).
  • When is a River not a River ? Consideration of the legal definition of a river for geomorphologists practising in New South Wales, Australia
  • Australia ; Concept ; Definition ; Environmental management ; Geomorphology ; Legislation ; New South Wales ; Perception ; River bed ; Stream ; Water resources
  • This paper examines why the definition of a river is an important and ongoing management issue, and outlines the development of legal definitions of river. Finally, the role of fluvial geomorphology is discussed with respect to the definition
  • of a river and its channel. This analysis will reveal whether the existing legislative framework adequately reflects the physical realities of rivers and watercourses so as to facilitate their conservation.
  • Annual bed-elevation regime in the alluvial channel of Squamish River, southwestern British Columbia, Canada
  • British Columbia ; Canada ; Carrying capacity ; Discharge ; Regression analysis ; River bed ; River regime ; Seasonal variation ; Stream
  • The aim of this study is to examine the annual regime of channel scour and fill by monitoring bed-elevation changes in a reach of Squamish River in southwestern British Columbia. The survey results show that bedload movement occurs as waves
  • or pulses forming bedwaves that appear to maintain an overall coherence with movement downstream. Although a weak seasonal effect is evident in this study, the bed-elevation regime is dominated by sediment supply-driven fluctuations in bedload transport
  • Bed-material mobility in a large river below dams
  • Carrying capacity ; Channel geometry ; Dam ; Ebro ; Flood ; Hydraulic works ; Impact ; River bed ; Sediment load ; Spain ; Stream
  • The mobility of river-bed surface particles is examined in the lower Ebro River downstream from dams that were closed several decades ago. Mobility is analysed by comparing photographs of painted bed areas taken before and after the 2003-2004 flood
  • Human-induced changes in bed shear stress and bed grain size in the River Waal (The Netherlands) during the past 900 years
  • In this study, the AA. analysed the combined effect of human activities on the flow and bed-sediment characteristics of the River Waal during the past 900 years. The AA. focus on 2 characteristics with a great geomorphological importance : the bed
  • shear stress and the bed grain size. Various data types were used, such as borehole descriptions, historical river maps and modern hydraulic data. In the discussion the causes of the historical change in bed shear stress and bed grain size are identified
  • and compared with observations in other rivers. Finally, it is shown how historical grain size information can be used for river restoration purposes.
  • Geochemical tracing and spatial evolution of the sediment bed load of the Romaine River, Québec, Canada
  • In order to characterise the present river bed load sources, sediment transport and sedimentary connectivity, a study was conducted to document the compositional continuum of the lower 300 km portion of the river. Bed load samples were collected
  • Euclidean distance coefficients were also calculated between consecutive samples along the river revealing major bed load compositional breaks. These results indicate a longitudinal fractionation of the bed load along the 300 km course of the river
  • . This is further supported by the sedimentary budget calculated from the annual sedimentary input derived from erosion rates of the river banks, from sediment bed load measurements at 3 gauging stations and from calculated bed load transport capacity at these 3
  • Burst-like sediment suspension events in a Sand bed river
  • British Columbia ; Canada ; Fluvial processes ; Ground survey ; Hydrodynamics ; River bed ; Sand ; Stream ; Suspended load ; Turbulence
  • L'A. propose des données sur les mouvements de turbulence dans le lit sablonneux de la Fraser River près de Mission, Colombie britannique, Canada. Il étudie également le rôle de ces mouvements sur la charge en suspension.―(A. Peyre).
  • Wood storage within the active zone of a large European gravel-bed river
  • Wood storage within the active zone of the dynamic, gravel-bed, Fiume Tagliamento, Italy, was investigated at 8 sites along the river's main stem. The objective was to study variations in the distribution and abundance of wood at a sample of sites
  • , in order to identify downstream trends and to understand how the controls on wood storage change along the length of the river.
  • Continuous monitoring of bedload flux in a mountain gravel-bed river
  • An automatic bedload monitoring station has been established on the perennial Tordera River, a Mediterranean mountain gravel-bed stream located in NE Spain. The AA. present data on channel-average bedload flux for this river and on the response
  • Reach scale variability of turbulent flow characteristics in a gravel-bed river
  • Canada ; Fluvial dynamics ; Gravel ; Quebec ; River bed ; Roughness ; Spatial variation ; Stream ; Turbulence
  • in the Eaton North River (Québec). At the reach scale, the distribution of individual roughness elements does not greatly control the spatial variability of turbulent flow properties.
  • Multi-scale characterization and evolution of channel forms in gravel-bed rivers
  • Supplementary data confirming the relationship between critical Shields stress, grain size and bed slope
  • Experimentation ; Grain size distribution ; Hydrological regime ; River bed ; Runoff ; Scotland ; Sediment transport ; Slope gradient ; Stream flow ; Threshold ; United Kingdom
  • This paper presents new experimental data on threshold conditions for motion of coarse uniform sediments. The experiments were conducted with gravel in a flume and included measurements of hydraulic characteristics and rate of bed particle movement
  • for a range of flows at different bed slopes. A reference transport method was used to define the beginning of sediment motion. The experimental data confirm the recent finding that the critical Shields stress for motion of coarse uniform sediment varies
  • with both grain size and bed slope.
  • Channel degradation and slope adjustment in steep streams controlled through bed sills
  • Catalonia ; Channel geometry ; Degradation ; Downcutting ; Ephemeral stream ; Hydraulic works ; Longitudinal section ; River bed ; Spain ; Stream ; Urban area ; Urban growth
  • The case-study of the Les Arenes-Palau-Rubí rivers is a system of 2 tributaries and a main river in northeast Spain, characterized by its short length, steepness and ephemeral nature. The comparison of bed profiles since 1962 revealed an incision
  • greater than 5.5 m. The main causes of degradation are thought to be channelization (width reduction) and urban growth. The equilibrium slopes with and without sills were obtained in 111 live-bed flume tests. It is demonstrated that the bed slope is milder
  • Prediction of alluvial channel pattern of perennial rivers
  • Braided channel ; Carrying capacity ; Channel geometry ; Discharge ; Flood ; Floodplain ; Fluvial processes ; Forecast ; Meander ; River bed
  • This paper attempts to predict the individual channel pattern of perennial rivers from independent boundary conditions defined by the river discharge and the bed material. The analysis is limited to wide alluvial floodplains, which do not restrict
  • the evolution of braided rivers. The analysis is further restricted to streams that are in dynamic equilibrium and that show neither rapid accretion nor incision.
  • Temporal variations in bedload transport rates and sediment storage in gravel-bed rivers
  • of the implications of variability for ideas of equilibrium in river channels.
  • Processes of Holocene terrace formation in a steep gravel-bed river, Nikko volcanic area, central Japan
  • Flume experiments suggest that, in a breaded stream, terraces are formed from bars under erosional conditions. This paper examines these processes of terrace formation with the aid of field data on the Holocene terraces of the Nedori River