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Stream power

About: Stream power is a research topic. Over the lifetime, 1135 publications have been published within this topic receiving 51324 citations.


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Journal ArticleDOI
TL;DR: In this article, the critical stream power values and hydrological regime together define the channel pattern, and analysis of the pattern type can be undertaken using effective discharge curves, which can be found in Figure 1.
Abstract: River channel patterns are thought to form a morphological continuum. This continuum is two-dimensional, defined by plan features of which there are three (straight, meandering, branching), and structural levels of fluvial relief of which there are also three (floodplain, flood channel, low-water channel). Combinations of these three categories define the diversity of patterns. One of the most important factors in channel development is stream power, defined by water discharge and river slope. The greater the stream power, the stronger the branching tendency, but threshold values of stream power are different for the three different hierarchical levels of channel relief. The critical stream power values and hydrological regime together define the channel pattern, and analysis of the pattern type can be undertaken using effective discharge curves. © 1998 John Wiley & Sons, Ltd.

77 citations

Journal ArticleDOI
TL;DR: In this article, the second part of a study on stratification effects by cohesive and non-cohesive sediment is described, and the hydrodynamic description of sediment transport is used to predict capacity conditions as a function of a dimensionless stream power, i.e., U3/hgWs.
Abstract: This paper describes results of the second part of a study on stratification effects by cohesive and noncohesive sediment. Winterwerp (2001) applied classical stratified flow theory implemented in a one-dimensional vertical numerical model (the 1DV POINT MODEL), showing that sediment-induced stratification effects may occur at already fairly small suspended sediment concentrations (i.e., a few 100 mg/L). We also discussed a basic difference between the behavior of cohesive and noncohesive sediment, which emerges as a result of the large water content of mud flocs. In this paper we elaborate further on the hydrodynamic description of the transport of fine suspended sediment by analyzing field and laboratory observations over a very large range of concentrations. We propose a sediment stability diagram to explain some features of hyperconcentrated flows, such as those observed in the Yellow River. We show that the behavior of hyperconcentrated flows is affected largely by hindered settling effects reducing the energy required to keep the sediment in suspension. The hydrodynamic description of sediment transport is used to predict capacity conditions as a function of a dimensionless stream power, i.e., U3/hgWs. This prediction agrees favorably with observations reported in literature covering four orders of magnitude in suspended sediment concentration.

77 citations

ReportDOI
29 Jun 2011
TL;DR: In this article, the authors present a full spatial-temporal assessment of tidal currents for the U.S. coastline down to the scale of individual devices is a barrier to the comprehensive development of tidal current energy technology.
Abstract: Tidal stream energy is one of the alternative energy sources that are renewable and clean. With the constantly increasing effort in promoting alternative energy, tidal streams have become one of the more promising energy sources due to their continuous, predictable and spatially-concentrated characteristics. However, the present lack of a full spatial-temporal assessment of tidal currents for the U.S. coastline down to the scale of individual devices is a barrier to the comprehensive development of tidal current energy technology. This project created a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal energy conversion technology. Tidal currents are numerically modeled with the Regional Ocean Modeling System and calibrated with the available measurements of tidal current speed and water level surface. The performance of the model in predicting the tidal currents and water levels is assessed with an independent validation. The geodatabase is published at a public domain via a spatial database engine and interactive tools to select, query and download the data are provided. Regions with the maximum of the average kinetic power density larger than 500 W/m2 (corresponding to a current speed of ~1 m/s), surface area larger than 0.5 km2 and depth larger than 5 m are defined as hotspots and list of hotspots along the USA coast is documented. The results of the regional assessment show that the state of Alaska (AK) contains the largest number of locations with considerably high kinetic power density, and is followed by, Maine (ME), Washington (WA), Oregon (OR), California (CA), New Hampshire (NH), Massachusetts (MA), New York (NY), New Jersey (NJ), North and South Carolina (NC, SC), Georgia (GA), and Florida (FL). The average tidal stream power density at some of these locations can be larger than 8 kW/m2 with surface areas on the order of few hundred kilometers squared, and depths larger than 100 meters. The Cook Inlet in AK is found to have a substantially large tidal stream power density sustained over a very large area.

76 citations

Journal ArticleDOI
TL;DR: In this article, the relation between equilibrium stream channel morphology and three independent governing variables, discharge, sediment supply, and valley slope, is investigated using a stream table using a generic physical model of a laterally active gravel bed stream.
Abstract: [1] The relation between equilibrium stream channel morphology and three independent governing variables, discharge, sediment supply, and valley slope, is investigated using a stream table. The experiments are based on a generic physical model of a laterally active gravel bed stream and directed by a recently published rational regime model. While a variety of channel adjustments are possible, the primary adjustment observed was in the channel slope. Other adjustments, such as surface armor composition and cross-sectional shape, were minor in comparison. The equilibrium slope is well predicted by a linear function of sediment concentration which is bounded by two thresholds: one associated with the minimum stream power necessary to deform the bed and the other associated with the maximum sediment feed that can be transported by the available flow. The results suggest that the system tends to move toward the minimum slope capable of transporting the sediment supply, in the process increasing the flow resistance for the system. Whether or not a minimum slope or a maximum system-scale flow resistance is reached cannot be determined given the available data, but there appears to be a unique slope (or, at least, a limited range of slopes) for which a stable alluvial channel morphology can be established for a given sediment concentration. The implications of this behavior are evaluated for the theoretical basis of the extremal hypothesis used to close the formulation of a rational regime model.

76 citations

Journal ArticleDOI
TL;DR: In this article, an equation for evaluating the sediment transport capacity of overland flow is presented, which is a necessary part of a physically based soil erosion model describing sediment detachment and transport as distributed processes.
Abstract: An equation for evaluating the sediment transport capacity of overland flow is a necessary part of a physically based soil erosion model describing sediment detachment and transport as distributed processes. At first, for the hydraulic conditions of small-scale and large-scale roughness, the sediment transport capacity relationship used in the WEPP model is calibrated by Yalin and Govers' equation. The analysis shows that the transport coefficient Kt depends on the Shields parameter, Y, according to a semi-logarithmic (Yalin) or a linear (Govers) equation. The reliability of the semi-logarithmic equation is verified by Smart's, and Aziz and Scott's experimental data. Then the Low's formula, whose applicability is also proved by Smart's, and Aziz and Scott's data, is transformed as a stream power equation in which a stream power coefficient, KSP, depending on Shields parameter, slope, sediment and water-specific weight, appears. A relationship between transport capacity and effective stream power is also proposed. Finally, the influence of rainfall on sediment transport capacity and the prediction of critical shear stress corresponding to overland flow are examined. © 1998 John Wiley & Sons, Ltd.

75 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202351
2022103
202154
202067
201952
201847