Browse by Archive
DigitalCommons@USU
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Major changes in the morphology of the Trinity River in California, such as narrowing of the cross section and sedimentation of fine sediment in pools, occurred after the closure of a system of dams. These changes caused a dramatic reduction in...
2011-01-01
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A mixed-size sediment transport model using only two fractions, sand and gravel, offers practical advantages in terms of the required input and conceptual advantages by readily incorporating the nonlinear effects of sand content on transport rate....
2002-01-01
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Fractional transport rates, bed surface texture, and bed configuration were measured after a mixed size sediment had reached an equilibrium transport state for seven different flow strengths in a recirculating laboratory flume. Fractional...
1989-01-01
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The dominant dimension of the step-pool bed form is its spacing, which is determined by the locations at which large, step-forming grains are deposited. We conducted laboratory experiments involving active transport of widely sorted sediment,...
2005-01-01
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We quantified all components of a fluvial sediment budget for a discrete flood on an aggrading gravel bed river. Bed load transport rates were measured at the upstream and downstream ends of a 4 km study area on the Provo River, Utah, during a...
2012-01-01
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To determine how differences in geomorphologic setting influence spatial heterogeneity in transport and uptake of limiting nutrients, we investigated reach-scale interactions between porous bed material textures, bed morphology, transient storage,...
2009-01-01
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Between 1830 and 1950 much of northeastern Puerto Rico was cleared for agriculture. Runoff increased by 50% and sediment supply to the river channels increased by more than an order of magnitude. Much of the land clearance extended to steep valley...
2000-01-01
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The transported load in most fluvial systems, including gravel-bedded rivers, includes fine-grained sediment. Models for suspended sediment transport have focused on sand-covered beds, rendering incomplete the theoretical and empirical framework...
2007-01-01
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Replicate velocity observations using conventional equipment under typical field conditions are used to evaluate the precision of different methods for estimating local boundary shear stress from velocity measurements. The bed shear velocity u,...
1996-01-01
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Two methods are commonly used to estimate the critical shear stress of individual fractions in mixed-size sediment, one using the largest grain displaced, the other using the shear stress that produces a small value of transport rate for each...
1988-01-01
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Transport rates of five sediments were measured in a laboratory flume. Three of these sediments had the same mean size, the same size distribution shape, and different values of grain size distribution standard deviation. The critical shear stress...
1988-01-01
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We measured a wide range of transport rates for five different sand/gravel mixtures in a laboratory flume. Each mixture used the same gravel, and sand was added to produce mixtures containing 6, 15, 21, 27, and 34% sand. Control of other variables...
2001-01-01
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We evaluate three metrics representing the drivers of channel change downstream from dams. A balance between changes in sediment supply and transport capacity identifies conditions of sediment deficit or surplus. A Shields number represents the...
2008-01-01
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Constant-discharge reservoir releases on the Trinity River, California, provide an unusual opportunity to unambiguously relate flow and gravel entrainment on a large gravel-bed river. Bed shear stress т0 was estimated using local observations of...
1996-01-01
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Partial transport is documented in the gravel bed channel of Carnation Creek using magnetically tagged stones. For four flood peaks the active proportion of surface grains was used to map streambed areas into distinct units of three different...
2003-01-01
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Grains of a single size within a mixed-size bed are entrained over a range of flows. Within this range some grains exposed on the bed surface are active (entrained at least once over the duration of a transport event), while the remaining surface...
1997-01-01
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Streambed surfaces are typically coarsened, or armored, at low flows, but there is little evidence of their condition during floods, when significant hydraulic and ecologic disturbance occurs. Some flume experiments have been used to conclude that...
2005-01-01
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Spatial complexity in channel geometry indicates that accurate prediction of sediment transport requires modeling in at least two dimensions. However, a one-dimensional model may be the only practical or possible alternative, especially for longer...
2007-01-01
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Reservoir releases may be specified to flush interstitial fine sediment from gravel beds in the river downstream. Choice of an effective flow depends on trade-offs among discharge, flow duration, and pool dredging as they determine rates of bed...
1996-01-01
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A series of community-led, large-scale laboratory experiments, termed “StreamLab”, were performed by the National Center for Earth-surface Dynamics (NCED) with the purpose of advancing multidisciplinary research, education, and knowledge transfer...
2013-01-01
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Twenty-eight coupled observations of flow, transport, and bed surface grain size distribution were made in a laboratory flume using a wide range of flows and a sediment with a very poorly sorted, bimodal grain size distribution. These observations...
1993-01-01
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Fractional transport rates are defined as the product of spatial grain entrainment, displacement length, and displacement frequency. Grain entrainment is defined relative to the population of grains on the bed surface at an initial time in order...
1997-01-01
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Reservoir releases may be specified for the purpose of maintaining or improving the downstream channel and habitat. A wide variety of ecological or management objectives may be defined for such flushing flows (which may be broadly divided into...
1996-01-01
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