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Flow resistance in steep mountain streams

Flow resistance in steep mountain streams
British Columbia ; Canada ; Channel geometry ; Discharge ; Mountain ; Roughness ; Runoff ; Slope gradient ; Stream ; Stream flow
The primary aim of this paper is to introduce new high-quality measured data on the hydraulics of a set of representative steep mountain channels located in the Coast Mountains of British Columbia as a representative guide to assessing flow
resistance in this type of environment. These data have been obtained for a range of discharges sufficient to define, for the low-flow domain, the at-a-station hydraulic geometry at each measurement site. A secondary aim of this paper is to discuss the nature
of total flow resistance in relation to that which might be attributed to grain roughness alone within the low-flow discharge domain.

Critical flow in rockbed streams with estimated values for Manning's n

Critical flow in rockbed streams with estimated values for Manning's n
Arizona ; Channel geometry ; Flood ; Fluvial hydrology ; River bed ; Roughness ; Runoff ; Stream ; Stream flow ; Turbulence ; United States of America
In this paper, n, Manning's roughness, is understood to include all forms of energy loss required to bring the Manning equation to an accurate estimate of mean velocity in the appropriate section. In subcritical flow it is probable that boundary
roughness is the primary component in energy loss, but in high-gradient and rough boundary systems turbulent and vertical losses assume a much increased importance in contribution to the n term. Application of the equation of critical flow to data from well
-known catastrophic flows provides surprisingly good estimates of Manning's n for these flows.

Measuring river velocities using GPS River Flow Tracers (GRiFTers)

Measuring river velocities using GPS River Flow Tracers (GRiFTers)
England ; Fluvial dynamics ; Global Positioning System ; Ground survey ; Methodology ; Stream ; Stream flow ; United Kingdom
This paper introduces the use of GPS drifters (termed GRiFTers) to measure surface flow velocities in a 400 m reach of the River Swale, UK. The technique shows great promise to provide new insights into flow patterns over long reaches of rivers
, over a range of flow conditions, and may also provide valuable data for numerical model validation.

Hyporheic flow as a potential geomorphic agent in the evolution of channel morphology in a gravel-bed river

Hyporheic flow as a potential geomorphic agent in the evolution of channel morphology in a gravel-bed river
Bank erosion ; Channel geometry ; Floodplain ; Hokkaido ; Hydrochemistry ; Japan ; Meander ; Stream ; Stream flow
This study examined Takahashi and Sasa's hypothesis of the influence of hyporheic flows on changes in channel form, particularly the formation of head-cut gullies, in an alluvial floodplain. A combination of hyporheic flow (sapping erosion
) and channel erosion (bank erosion) appeared to contribute to the formation of the head-cut gullies. Hyporheic flow is an important component in the geomorphic evolution of channels and the floodplain in a gravel-bed river.

The effect of bedload transport on mean and turbulent flow properties

The effect of bedload transport on mean and turbulent flow properties
Carrying capacity ; Energy balance ; Experimentation ; Roughness ; Runoff ; Stream ; Stream flow ; Turbulence
This paper present the results of a flume experiment that was designed to investigate the effect of bedload transport on mean and turbulent properties of the flow. The data obtained from the experiment show that bedload transport may either cause
the flow to decelerate or accelerate , depending on the roughness of the bed, hydraulic conditions, and bedload transport rate. A deeper understanding of the feedback effects of bedload is gained by taking into account the turbulent component of the flow.

Effects of a pebble cluster on the turbulent structure of a depth-limited flow in a gravel-bed river

Effects of a pebble cluster on the turbulent structure of a depth-limited flow in a gravel-bed river
Canada ; Gravel ; Hydrodynamics ; Micromorphology ; Quebec ; Stream ; Stream flow ; Turbulence
This paper presents original results from measurements of velocity taken at a high spatial and temporal resolution in a turbulent flow upstream and downstream from a pebble cluster. The high sampling resolutions in a natural environment permitted
characterization of the complex dynamics of the turbulent flow in the vicinity of the cluster. The description of these dynamics is based on the interpretation of contour maps of several turbulence statistics. Results indicate the existence of highly dynamic
boundaries between zones where strong intermittent events are generated. They also highlight the difference between shedding and upwelling motions of the flow.

Effects of flow regulation on flow regime in the Murrumbidgee River, South Eastern Australia : an assessment using a daily estimation hydrological model

Effects of flow regulation on flow regime in the Murrumbidgee River, South Eastern Australia : an assessment using a daily estimation hydrological model
Australia ; Flood ; Hydraulic works ; Hydrological regime ; Model ; New South Wales ; Stream ; Stream flow ; Water management
In this paper, modelled hydrological data are used to quantify the effects of regulation on the flow regime of the lower Murrumbidges River in the period 1970-1988. The comparison of modelled natural and regulated daily flows shows the magnitude
of changes to mean and seasonal flows, flood peaks and flow duration. The AA. compared historical regulated data with modelled natural data over a common 29 year period to eliminate the effect of secular climate change on flow data and the daily time-step

Mesuring streambank erosion due to ground water seepage : correlation to bank pore water pressure, precipitation and stream stage

Mesuring streambank erosion due to ground water seepage : correlation to bank pore water pressure, precipitation and stream stage
Bank erosion ; Mississippi ; Porosity ; Precipitation ; Soil properties ; Stratigraphy ; Stream ; Underground flow ; United States of America
The aim of this research was to demonstrate the importance of streambank composition and stratigraphy in controlling seepage flow and to quantify correlation of seepage flow/erosion with precipitation, stream stage and soil pore water pressure

Hydraulic geometry and changes in flow velocity at a river confluence with coarse bed material

Hydraulic geometry and changes in flow velocity at a river confluence with coarse bed material
The purpose of this paper is to report observations of flow processes occuring at a natural stream confluence and to illustrate the interactions between form and flow as water stage is varied. Changes in flow velocity at the confluence will also

Analysis of the influence of gully erosion in the flow pattern of catchment streams, Southeastern Brazil

Analysis of the influence of gully erosion in the flow pattern of catchment streams, Southeastern Brazil
Brazil ; Gully erosion ; Human impact ; Hydrochemistry ; Hydrological regime ; Minas Gerais ; Precipitation ; Runoff ; Stream flow ; Watershed
In order to analyze the influence of erosion in the hydrological behavior of small streams, two similar catchments of the upper portion of the Velhas River were simultaneously monitored throughout a hydrological year. Rainfall, stream flow
and hydrochemical data were sytematically collected. The results showed that the eroded catchment presented smaller baseflow rates and bigger but short-lived stormflows. This contrasting flow regime is attributed to the gully, which is causing the partial withdraw

The spatial distribution of low flows in Poland not exceeded at an assumed probability

The spatial distribution of low flows in Poland not exceeded at an assumed probability
Discharge ; Fluvial hydrology ; Low water ; Poland ; Statistical distribution ; Stream ; Stream flow
This paper presents the results of a fitting of most frequently-applied probability distributions to a series of minimum yearly flows. Specifically, the series of minimal annual discharges derived from 119 stream gauges located throughout Poland

High-resolution analysis of debris flow-induced channel changes in a headwater stream, Ashio Mountains, Japan

High-resolution analysis of debris flow-induced channel changes in a headwater stream, Ashio Mountains, Japan
Channel geometry ; Debris flow ; Fluvial dynamics ; Geomorphometry ; Geophysics ; Honshu ; Japan ; Mountain ; Sampling ; Stream
Changes in channel size and shape caused by a debris flow event along the length of a headwater stream (HWS) in the Ashio Mountains were captured with the aid of repeat high-definition surveys using terrestrial laser scanning (TLS) techniques
. The HWS was classified into 3 distinct reaches below the debris flow initiation zone. Morphometric analyses from the TLS point cloud revealed that debris flow erosion produced a distinct nonlinear change in channel dimensions in the downstream direction

The Steensby Inlet ice stream in the context of the deglaciation of northern Baffin Island, eastern Arctic Canada

The Steensby Inlet ice stream in the context of the deglaciation of northern Baffin Island, eastern Arctic Canada
This paper deals with the glacial history of northern Baffin Island. Its main focus is the glacial bedforms and debris dispersal attributed to the Steensby Inlet flow event, which is interpreted as an ice stream. Antecedent conditions
are illustrated based on recent mapping. The evolution of the ice cover, including its thickness, flow patterns, moraine construction, debris dispersal and inferred ice streams, is presented. The Steensby Inlet flow event and inferred ice stream are then discussed
. Finally, the paper details the devolution of the ice stream into streams of decreasing size and discusses associated corridors of evacuation and lateral sliding scarps.

Field observations on hyperconcentrated flows in mountain torrents

Field observations on hyperconcentrated flows in mountain torrents
Alps (The) ; Carrying capacity ; Catastrophe ; Flood ; Germany ; Hydrodynamics ; Mountain ; Pic discharge ; Pyrénées ; Spain ; Stream ; Stream flow ; Torrent
The purpose of this paper is to report on observations of flow and sediment dynamics in hyperconcentrated flows during 2 extremely high magnitude events in relation with man-made constructions : the Arás flood which occurred in 1996 in the Central

The effect of stage on flow and components of the local force balance

The effect of stage on flow and components of the local force balance
Braided channel ; Channel geometry ; Discharge ; Fluvial processes ; Meander ; Model ; River bed ; Stream flow ; Topography ; United States of America ; Wyoming
Flow fields and water and bed surface topography were measured at 2 different stages as flow shoals over a submerged mid-channel bar in a straight reach downstream of a bend in Solfatara Creek, Wyoming. The data allow calculation and comparison
of the magnitude of the component terms in the downstream and cross-stream force balance at the different stages.

A study of physico-geographical factors for formation of hyperconcentrated flows in the Loess Plateau of China

A study of physico-geographical factors for formation of hyperconcentrated flows in the Loess Plateau of China
Aeolian deflation ; Aeolian features ; China ; Loess ; Plateau ; Runoff ; Seasonal variation ; Stream ; Stream flow ; Suspended load ; Topography ; Vegetation
Most of the data used in this study come from hydrometric stations in the Yellow River basin. The purpose of this study is to elucidate the formation of hyperconcentrated flow in relation to physico-geographical factors at macro spatial scales, so
this paper is focused on hyperconcentrated flows in river channels only, and does not discuss those on slopes or in gullies.

Migratory behaviour of adult fast-growing brown trout (Salmo trutta, L.) in relation to water flow in a regulated norwegian river

Migratory behaviour of adult fast-growing brown trout (Salmo trutta, L.) in relation to water flow in a regulated norwegian river
Biogeography ; Discharge ; Fish ; Hydraulic works ; Migration ; Norway ; Population dynamics ; Stream ; Stream flow
The migration pattern of spawners of brown trout (Salmo trutta) in relation to water flow was analysed by radio-tracking in the regulated River Gudbrandsdalslågen, Norway. By being able to follow individual fish on their migration, the AA. were able
to study the effect of specially induced high flows and to determine the minimum discharge values to safeguard the spawning migration of the Hunder trout.

Nonlinear determinism in river flow : prediction as a possible indicator

Nonlinear determinism in river flow : prediction as a possible indicator
Determinism ; Fluvial dynamics ; Forecast ; Methodology ; Runoff ; Stream ; Stream flow
This study addresses the issue of nonlinear determinism in river flow series using prediction as a possible indicator. First, a brief account of the nonlinear local approximation method and the inverse approach to identify nonlinear determinism
is presented. Next, a review of the studies that have attempted river flow predictions using the nonlinear deterministic method is provided, followed by a discussion on the presence of nonlinear determinism through the inverse approach. Conclusions and scope

Bedload transport resistance in rough open-channel flows

Bedload transport resistance in rough open-channel flows
Carrying capacity ; Experimentation ; Hydrodynamics ; Stream ; Stream flow ; Turbulence
Based on experiments in 2 flumes with fixed and mobile plane beds and previously published data, an equation is developed that may be used to predict bedload transport resistance for both capacity and non-capacity flows. The variables
in this equation are identified by dimensional analysis and the coefficients are determined by non-linear regression. This equation applies to rough turbulent open-channel flows, where the relative submergence is between 1 and 20 and the entire sediment load moves

Structure of flow over alluvial bedforms : an experiment on linking field and laboratory methods

Structure of flow over alluvial bedforms : an experiment on linking field and laboratory methods
Experimentation ; Illinois ; Longitudinal section ; River bed ; Sediment transport ; Sedimentary structure ; Stream ; Stream flow ; Turbulence ; United States of America
This paper presents results of a field study designed to examine the structure of flow over mobile and fixed bedforms in a natural stream and to compare the results with findings of previous laboratory studies within the framework of double time
to the understanding of turbulent flow structure over migrating bedforms and the relation of this flow structure to turbulent flow over artificial, non-migrating bedforms.

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