Baardvik, B.M., and M. Jobling, Effect of Size-Sorting On Biomass Gain and Individual Growth- Rates in Arctic Charr, Salvelinus-Alpinus L, Aquaculture, 90 (1), 11-16, 1990.


Booman, A.C., M.A. Parin, and A. Zugarramurdi, Efficiency of size sorting of fish, International Journal of Production Economics, 48 (3), 259-265, 1997.

Machine sorting can reduce production costs by increasing the yield in the heading operation, and the overall efficiency of the rest of the line. It also adds quality to end products, but in turn increases investment and process complexity. When the process involved is raw material and labour cost-intensive processes, small increases in yield and productivity lead to important cost reductions. The advantages and draw-backs of fish sorting by size are analysed as a function of parameters such as size distribution and cost structure of the industry. A general model to estimate cost variations is developed. Figures are presented for anchovy canning in Argentina. When the proportion of small anchovies is high, savings of more than 8% of the total unit cost can be obtained. For average conditions, daily production of only 3000 cans in one season is enough to pay for the sorting machine.

Bridge, J.S., A Revised Model For Water-Flow, Sediment Transport, Bed Topography and Grain-Size Sorting in Natural River Bends, Water Resources Research, 28 (4), 999-1013, 1992.

A revised model for the interaction of water flow, bed topography, and the rate and mean grain size of bed load in river bends is presented and compared with a large range of observational data. The model represents a modification of the approaches used by F. Engelund, J. S. Bridge, G. Parker, S. Ikeda, and coworkers. Model predictions generally agree with data from the River South Esk, Muddy Creek, River Dommel, and Hooke's laboratory channel. This simple model apparently performs at least as well as more complicated flow models. To make further improvements it is necessary to more accurately specify the interaction between local bed shear stress, sediment transport, and the local bed configuration.

Bryant, E., Edge Wave and Sediment Sorting Relationships On Beach Foreshores, Broken Bay, Search, 10 (12), 442-444, 1979.


Church, M., Sediment sorting in gravel-bed rivers, Journal of Sedimentary Research, 69 (1), 20-20, 1999.


Frihy, O.E., M.F. Lotfy, and P.D. Komar, Spatial Variations in Heavy Minerals and Patterns of Sediment Sorting Along the Nile Delta, Egypt, Sedimentary Geology, 97 (1-2), 33-41, 1995.

Sand samples were collected along 34 beach profiles spanning the 240-km length of the Nile Delta in order to examine the sorting patterns of heavy minerals that develop during cross- shore and alongshore sediment transport. Factor analysis of the heavy-mineral contents shows that two mineral factors or groups result from sorting due to the contrasting densities and sizes of the grains. One factor is dominated by augite, hornblende and epidote, while the second factor consists of opaques, garnet, zircon, rutile and monazite. Minerals of factor 1 are of lower densities and coarser sizes, and represent the grains that are selectively entrained by waves and currents in areas of beach erosion and preferentially transported to zones of beach accretion where they are deposited. The higher-density minerals of factor 2 tend to become concentrated in areas of beach erosion, accounting for the formation of black-sand placers where the erosion has been greatest. The spatial distributions of these two factors reflect the grain-sorting patterns of the heavy minerals which coincide with the general trends of shoreline erosion versus accretion that exist along the length of the delta. There is also a distinctive pattern of cross-shore sorting, with factor 2 containing the denser minerals being best developed within the inner surf zone, generally with a maximum at the shoreline. Its development corresponds to the formation of black-sand concentrates on the beach face where erosion has been greatest, implying that grain sorting has taken place mainly within the swash zone. There is a general decrease in factor 2 relative to factor 1 toward the offshore, often with oscillations that are congruent with the beach topography; factor 1 with the lower-density minerals is greatest over offshore bars where deposition has prevailed.

Gundersen, L.C.S., The Effect of Rock Type, Grain-Size, Sorting, Permeability, and Moisture On Measurements of Radon in Soil Gas - a Comparison of 2 Measurement Techniques, Journal of Radioanalytical and Nuclear Chemistry-Articles, 161 (2), 325-337, 1992.

Soil surveys of radon conducted in the Coastal Plain of New Jersey, Alabama and Texas indicate that soil composition and grain size exert the strongest control on the concentration of radon measured. Soil-gas radon was measured in-situ using two techniques; one developed by G. Michael REIMER of the U. S. Geological Survey; the other developed by Rogers and Associates Engineering Corp. for use by the Environmental Protection Agency. The Reimer technique aquires a small-volume, grab sample of soil gas, whereas the Rogers and Associatess technique acquires a large-volume, flow-through sample of soil gas. The two techniques yield similar radon concentrations in well-sorted sands, but do not correlate as well for poorly sorted soils and clays.

Hairsine, P.B., G.C. Sander, C.W. Rose, J.Y. Parlange, W.L. Hogarth, I. Lisle, and H. Rouhipour, Unsteady soil erosion due to rainfall impact: a model of sediment sorting on the hillslope, Journal of Hydrology, 220 (3-4), 115-128, 1999.

A new method is presented for predicting sediment sorting associated with soil erosion by raindrop impact for non- equilibrium conditions. The form of soil erosion considered is that which results from raindrop impact in the presence of shallow overland flow itself where the flow is not capable of eroding sediment. The method specifically considers early time runoff and erosion when sediment leaving an eroding area is generally finer and thus may have a higher potential for transport of sorbed pollutants. The new mechanism described is the formation of a deposited layer on the soil surface, which is shown to lead to sediment sorting during an erosion event. The deposited layer is taken to have two roles in this process: to temporarily store sediment on the surface between successive trajectories, and to shield the underlying soil from erosive stresses. Equations describing the dynamics of the suspended sediment mixture and the deposited layer are developed. By integrating these equations over the length of eroding land element and over the duration of the erosion event, an event- based solution is proposed which predicts total sediment sorting over the event. This solution is shown to be consistent with experimentally observed trends in enrichment of fine sediment. Predictions using this approach are found to only partly explain measured enrichment for sets of experimental data for two quite different soils, but to be in poor agreement for an aridsol of dispersive character. It is concluded that the formation of the deposited layer is a significant mechanism in the enrichment of fine sediment and associated sorbed pollutants, but that processes in the dispersive soil are not as well described by the theory presented. (C) 1999 Elsevier Science B.V. All rights reserved.

Hartmann, D., and D. Bowman, Efficiency of the Log-Hyperbolic Distribution - a Case-Study - Pattern of Sediment Sorting in a Small Tidal-Inlet - Het Zwin, the-Netherlands, Journal of Coastal Research, 9 (4), 1044-1053, 1993.

Sediment sorting dispersal pattern in The Zwin tidal-inlet, The Netherlands, was studied using grain size data. The descriptive power of the log-hyperbolic distribution model, the hyperbolic shape triangle, current meters recordings and bedform analysis were applied. The process-oriented discriminating approach suggests four distinct log-hyperbolic grain size curves, related to four morphodynamic sub- environments along The Zwin Inlet. The log-hyperbolic shape indicates, in response to the governing dynamics, a gradual change from erosive, at the inlet front, to a depositional sedimentary facies inland. Applying the population concept, the Zwin supersample, the combined total sampled grain size population, falls into the right wing of the hyperbolic shape triangle, indicating a winnowed-erosional facies (rho = 0.44) which is the main sedimentary fingerprint of The Zwin Inlet. It indicates winnowing-out of the suspended fraction, supposedly complementary to a similar sedimentary heritage from the longshore drifted sediments.

Iseya, F., and H. Ikeda, Pulsations in Bedload Transport Rates Induced By a Longitudinal Sediment Sorting - a Flume Study Using Sand and Gravel Mixtures, Geografiska Annaler Series a-Physical Geography, 69 (1), 15-27, 1987.


James, C.S., G. Lymberopoulos, and P. Scalla, An Experimental-Study of the Effect of Bed Grain Roughness On Sediment Sorting By Entrainment, Water Sa, 16 (4), 257-264, 1990.


Jerram, D.A., Visual comparators for degree of grain-size sorting in two and three-dimensions, Computers & Geosciences, 27 (4), 485-492, 2001.


Liang, T., Optimize Agricultural Product Size Sorting Operation By Dynamic Programming Method, Journal of Agricultural Engineering Research, 14 (2), 139-&, 1969.


Liffman, K., and M. Brown, The Motion and Size Sorting of Particles Ejected From a Protostellar Accretion Disk, Icarus, 116 (2), 275-290, 1995.

We attempt to estimate the size range of particles that are ejected from a protostellar accretion disk by a protostellar jet, An n-body code is used to determine the subsequent motion of the ejected particles, where the particles are subject to two forces: the gravitational attraction from the protostar and the gas drag from the halo gas of the accretion disk. It is highly probable that a protosolar jet existed at the very beginning of the Solar System. Such a jet may have influenced the chemical structure of the solar nebula by recycling heated material back into the nebula. Protostellar jets eject a considerable amount of mass (10(-3)-10(-1) M(.)) over a long lifetime (10(6)-10(7) years), so some evidence of a protosolar jet may still be detectable in the most primitive surviving objects of the solar nebula, chondritic meteorites. Protostellar jets appear to be formed from the innermost regions (less than or equal to 0.1 AU) of protostellar accretion disks. At such close proximity to the protostar, one would expect any nongaseous disk material to be in a molten or semimolten state. We have made an analysis of the expected droplet size that can be ejected by the jet flow and find that the droplet radius is <1 cm. The gas densities and speeds required to eject such large objects from the close environs of a protostar have been shown (in previous studies) to be well within theoretically expected and observationally confirmed ranges. Our calculations, however, suggest that ejection of such large objects requires the scale height of the inner accretion disk to be compressed by two orders of magnitude relative to the usual isothermal scale height. Using a parameterized solution to an outflow jet, we find that 0.1-cm- sized projectiles can become decoupled from the outflow at distances in excess of 0.01 AU above the midplane of the accretion disk. The subsequent motion of these objects is shown to be a linear path across the face of the accretion disk. If these ejected particles pass through a sufficiently large section of the accretion disk's upper atmosphere, then their speed will become smaller than the escape velocity, and the particles will settle back to the accretion disk. It is shown that the denser and larger a particle is, the further it can travel through the gas halo of an accretion disk, thereby producing density-dependent size-sorting of particles. Since chondrules have radii (less than or equal to 1 cm) that are inversely proportional to their density, it is suggested that chondrules are ablation droplets produced by a protostellar jet. (C) 1995 Academic Press, Inc.

Lind, B.B., The influence of grain-size and sediment sorting on the hydraulic conductivity of some Swedish tills, Gff, 121, 107-111, 1999.

Porosity, grain-size distribution and sorting were studied in relation to hydraulic conductivity of 44 undisturbed till samples from three different sites in western Sweden. In addition, grain roundness and roughness of ten of the samples was studied. The results show that neither the porosity nor the grain parameters are sufficient to describe the hydraulic properties of till. In spite of the relatively uniform texture, hydraulic conductivity varied considerably from sample to sample, from about 10(-9) m/s up to more than 10(-5) m/s. The results should be regarded as confirmation of the crucial role of structure in determining the hydraulic conductivity of till. Grain sorting, and above all grain orientation, which in turn is connected to layering, lamination and fissility structures, are among the most important factors for determining hydraulic conductivity and anisotropy of till. There appears to be no relationship between the hydraulic conductivity and the parameters roughness, sphericity and mean grain size. In the same way the total porosity of the studied tills is more or less independent of the grain size but somewhat correlated to grain sorting.

McLean, R.F., and R.M. Kirk, Relationships Between Grain Size Size-Sorting and Foreshore Slope On Mixed Sand-Shingle Beaches, New Zealand Journal of Geology and Geophysics, 12 (1), 138-&, 1969.


Paluch, I.R., Size Sorting of Hail in a 3-Dimensional Updraft and Implications For Hail Suppression, Journal of Applied Meteorology, 17 (6), 763-777, 1978.


Passega, R., Sediment Sorting Related to Basin Mobility and Environment, American Association of Petroleum Geologists Bulletin, 56 (12), 2440-2450, 1972.


Powell, D.M., Patterns and processes of sediment sorting in gravel-bed rivers, Progress in Physical Geography, 22 (1), 1-32, 1998.

Sedimentological studies of coarse-grained alluvial rivers reveal patterns of bed material sorting at a variety of spatial scales ranging from downstream fining over the length of the long profile to the vertical segregation of a coarse surface layer at the scale of individual particles. This article reviews the mechanisms that sort bed material by size during sediment entrainment, transport and deposition and discusses some of the inter-relationships that exist between patterns and processes of sediment sorting at different spatial and temporal scales. At initiation of motion, sorting can arise from the preferential entrainment of the finer fractions from the heterogeneous bed sediments. Bedload grain-size distributions are modified during transport as different size fractions are routed along different transport pathways under the influence of nonuniform bed topography and associated flow patterns, and during deposition as the variable pocket geometry of the rough bed surface and turbulence intensity of the flow control the size of the particles that deposit. The review highlights the poor understanding of the many feedback linkages that exist between patterns and processes of sediment sorting at different scales and the need for a greater awareness of the spatial and temporal bounds of these linkages.

Presley, M.A., and P.R. Christensen, The effect of bulk density and particle size sorting on the thermal conductivity of particulate materials under Martian atmospheric pressures, Journal of Geophysical Research-Planets, 102 (E4), 9221-9229, 1997.

Preliminary measurements of the effects of bulk density and particle size sorting on the thermal conductivity of particulate materials under Martian atmospheric pressures are presented and discussed. Concoidally fractured particles tend to form: more loosely packed, less dense sedimentary structures, due to irregularities in the shape of the particles, than those formed by spherical particles of similar size. The lower bulk density of the angular-shaped particles leads to a lower thermal conductivity of the sample. If the density difference is assumed to be the sole factor that controls the difference in conductivity in this case, then the thermal conductivity of 25-30 mu m size particles appears to increase linearly with increasing bulk density and with the square root of the atmospheric pressure. Initial experiments appear to indicate that the bulk thermal conductivity of a particulate material containing a mixture of different particle sizes is the same as the thermal conductivity that a material of similar bulk density would have if it were composed entirely of the largest particle size contained within that material. More studies are, however, necessary to confirm this apparent trend.

Rosato, A.D., Y. Lan, and D.T. Wang, Vibratory Particle-Size Sorting in Multicomponent Systems, Powder Technology, 66 (2), 149-160, 1991.

Particle size segregation of granular mixtures due to shaking or vibrations has been observed in industries concerned with the handling and processing of particulates. Upon introducing the concept of relative concentrations between each size species, this paper presents a segregation model from which generalized expressions are derived for the instantaneous rate of change of concentration of each size species. The expressions are specialized to a ternary system. A Monte Carlo computer simulation study is done to simulate size sorting in a ternary system at a fixed shaking amplitude. The results of the simulations show good agreement with model predictions regarding the influence of particle size ratios. The most striking effect is a reversal of sorting order between the small and large particles with a change of size ratios. This reversal, which occurs in the simulated system, is clearly explained by the model.

Sengupta, S., Size-Sorting During Suspension Transportation - Lognormality and Other Characteristics, Sedimentology, 22 (2), 257-273, 1975.


Thompson, D.M., E.E. Wohl, and R.D. Jarrett, Revised velocity-reversal and sediment-sorting model for a high-gradient, pool-riffle stream, Physical Geography, 17 (2), 142-156, 1996.

Sediment-sorting processes related to varying channel-bed morphology were investigated from April to November 1993 along a 1-km pool-riffle and step-pool reach of North Saint Vrain Creek, a small mountain stream in the Rocky Mountains of northern Colorado. Measured cross-sectional areas of flow were used to suggest higher velocities in pools than in riffles at high flow. Three hundred and sixteen tracer particles, ranging in size from 16 mm to 256 mm, were placed in two separate pool- riffle-pool sequences and used to assess sediment-sorting patterns and sediment-transport competence variations. Tracer- particle depositional evidence indicated higher sediment- transport competence in pools than in riffles at high flow. Pool-riffle sediment sorting may be created by velocity reversals, and more localized sorting results from gravitational forces along the upstream sloping portion of the channel bed located at the downstream end of pools.

Thompson, D.M., E.E. Wohl, and R.D. Jarrett, Velocity reversals and sediment sorting in pools and riffles controlled by channel constrictions, Geomorphology, 27 (3-4), 229-241, 1999.

Keller [Keller, E.A,, 1971. Areal sorting of bed-load material: the hypothesis of velocity reversal. Geological Society of America Bulletin 82, 753-756] hypothesized that at high flow, near-bed velocities in pools exceed velocities in riffles and create pool scour. Pools, however, typically have larger cross- sectional areas of flow at bankfull discharge. This condition raises an inconsistency with Keller's velocity reversal hypothesis and the one-dimensional continuity of mass equation. To address this problem, a model of pool maintenance and sediment sorting is proposed that relies on constriction of flow by recirculating eddies and flow divergence over the exit- slopes of pools. According to the model, a narrow zone of high velocity occurs in the center of pools, creating scour. Along the downstream end of pools, an uphill climb of particles up the pool exit-slope promotes sediment deposition. The model is tested with field and flume measurements of velocity, water- surface elevation, and size of bed sediments in recirculating- eddy influenced pools. Local reversals of the water-surface gradient were measured in the field and a velocity reversal was created in the flume. The reversals that were measured indicate higher gradients of the water surface over the upstream portions of pools and higher velocities in pools at high flow. The distribution of bed sediments collected in the field also support the proposed model of pool maintenance. (C) 1999 Elsevier Science B.V. All rights reserved.

Thompson, D.M., and K.S. Hoffman, Equilibrium pool dimensions and sediment-sorting patterns in coarse-grained, New England channels, Geomorphology, 38 (3-4), 301-316, 2001.

Pools and riffles are natural bedforms that produce variations in width and depth along channels deemed critical for aquatic habitat. An understanding of this morphology is necessary for the successful design of a reconstructed or restored channel. To better understand pool geometry and sorting characteristics of New England channels, characterizations of pool geometry were performed on 145 different pools strongly influenced by channel constrictions. Characterizations of channel-bed sediments were also performed at 34 of these locations. Data from 120 pools were used in least-squares, multiple-regression analysis with 19 different independent variables to develop prediction equations for pool depth, length, and exit-slope gradient. These equations were then tested using the 25 remaining pools. Eighteen different geometric variables were then used to predict sediment phi (50) values in pool centers, pool exit slopes, and riffles for the subset of 34 samples. The regression analyses for pool geometry indicate that pool depth is significantly influenced to a decreasing degree by pool exit-slope width, constriction gradient, constriction width, drainage area, upstream channel width, and the exit-slope expansion ratio, with an R-2 value of 0.53. Similarly, pool length is influenced by channel gradient, location of the channel constriction, pool width, drainage area and constriction length, with an R-2 value of 0.72. The gradient of pool exit slope is influenced by drainage area, channel gradient, and constriction gradient, with an R-2 value of 0.34. However, R-2 values for exit slope increased to 0.65 when sediment d(50) data were utilized. Using the resulting regression equations to predict dimensions fur the 25 verification pools yields average residuals near zero, although moderate variations do exist. A Tukey-Kramer HSD comparison of the means for sediment phi (50) values indicates pool sediments are significantly coarser than pool exit-slops and riffle sediments for the subset of 34 pools. Regression analyses also suggest significant relations between the size of sediments in pools and riffles and a combination of geometric variables with R-2 values that range from 0.45 to 0.62. The results suggest that pool dimensions are related to basin-wide variability and local hydraulic conditions. The findings also suggest that the characteristics of constrictions and the downstream section of pools provide an important control on scouring and sorting characteristics throughout the pool-riffle morphology. (C) 2001 Elsevier Science B.V. All rights reserved.

Yen, C., and K.T. Lee, Bed Topography and Sediment Sorting in Channel Bend With Unsteady-Flow, Journal of Hydraulic Engineering-Asce, 121 (8), 591-599, 1995.

Bed topography and transverse sediment sorting in an alluvial channel bend were investigated under unsteady-flow conditions with nonuniform sediment. Five experiments, each having the same initial sediment-size gradation but a different inflow hydrograph, were done in a 180 degrees channel bend with a constant radius of curvature. In addition, bed elevations across various sections of the bend were measured, and bed- surface sediment were sampled at the peak and end of the hydrograph in each experiment. Experimental results indicated that the characteristics of the hydrograph have prominent influences on bed topography and transverse sediment sorting. Those cases with a higher ramping rate of the hydrograph have greater deposition heights near the inner bank and larger scour depths near the outer bank. Furthermore, the sediment is finer near the inner bank and coarser near the outer bank in cases with a higher ramping rate. The bed deformation and sediment- size variation correlated well with the unsteady-flow parameter defined in this study. Furthermore, regression relations for transverse bed profile, transverse variation of sediment size, and total amount of sediment discharge were established in terms of the unsteady-flow parameter.