Unsteady soil erosion model, analytical solutions and comparison with experimental results

Sander, G. C.; Hairsine, Peter B.; Rose, C. W.; Cassidy, Dennis S.; Parlange, Jean‐Yves; Hogarth, W. L.; Lisle, I. G.

doi:10.1016/0022-1694(95)02810-2

Cited by 74 publications

(130 citation statements)

References 9 publications

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“…Possible processes that explain supply variation and the pattern displayed in these figures are the exhaustion of readily available soil from the land and growth of vegetative cover. In addition, Hairsine and Rose (1991) report that during individual storms a protective layer of soil can form to limit detachment of sediment particles, and Sander et al (1996) found that initial high sediment concentrations have a much greater fraction of fine sediments than later concentration values. However, when we tried to find this protective layer under natural conditions, we could not find it (not shown).…”

Section: Similarity Of All Three Watershedsmentioning

confidence: 99%

Suspended sediment concentration–discharge relationships in the (sub-) humid Ethiopian highlands

Guzmán

Tilahun

Zegeye

et al. 2013

Hydrol. Earth Syst. Sci.

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Abstract. Loss of top soil and subsequent filling up of reservoirs in much of the lands with variable relief in developing countries degrades environmental resources necessary for subsistence. In the Ethiopia highlands, sediment mobilization from rain-fed agricultural fields is one of the leading factors causing land degradation. Sediment rating curves, produced from long-term sediment concentration and discharge data, attempt to predict suspended sediment concentration variations, which exhibit a distinct shift with the progression of the rainy season. In this paper, we calculate sediment rating curves and examine this shift in concentration for three watersheds in which rain-fed agriculture is practiced to differing extents. High sediment concentrations with low flows are found at the beginning of the rainy season of the semi-monsoonal climate, while high flows and low sediment concentrations occur at the end of the rainy season. Results show that a reasonably unique set of rating curves were obtained by separating biweekly data into early, mid, and late rainfall periods and by making adjustments for the ratio of plowed cropland. The shift from high to low concentrations suggests that diminishing sediment supply and dilution from greater base flow during the end of the rainfall period play important roles in characterizing changing sediment concentrations during the rainy season.

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Section: Similarity Of All Three Watershedsmentioning

confidence: 99%

Suspended sediment concentration–discharge relationships in the (sub-) humid Ethiopian highlands

Guzmán

Tilahun

Zegeye

et al. 2013

Hydrol. Earth Syst. Sci.

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“…It is microtopography and hydraulic conditions that emphasize either the effects of rainfall or those of overland flow. As a first step before further development of the model a single representative particle size is used although the studies of Sander et al [1996], Hairsine et al [1999], Heilig et al [2001], and Beuselinck et al [2002] demonstrate clearly the need for multisize class depositional models. Here we present the model and its evaluation over a plane surface and an illustration of its capabilities to deal with a real topography plot.…”

Section: Introductionmentioning

confidence: 99%

PSEM_2D: A physically based model of erosion processes at the plot scale

Nord

Estèves

2005

Water Resources Research

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[1] This paper presents the development and first applications of the Plot Soil Erosion Model 2D (PSEM_2D). Infiltration is computed using a Green and Ampt model, overland flow is computed using the depth-averaged two-dimensional unsteady flow equations (Saint Venant equations), and soil erosion is computed by combining the equation of mass conservation of sediment and a detachment-transport coupling model for erosion by runoff. A shear stress approach is used to determine the transport capacity. The formation of a covering cohesionless layer as a result of depositing sediment and action of rainfall impact before runoff is considered. The erosion processes involved are rainfall and runoff detachment of original soil, rainfall redetachment, and overland flow entrainment of sediment from the deposited layer, and deposition. The model uses a single representative particle size. Complex rainfall events on natural slopes can be simulated. The accuracy of the predictions for erosion of planar surfaces is tested by comparison with observed data obtained from experiments and with an analytical solution. Good agreement between the calculated results and measured data was found. A sensitivity analysis was also performed. Limitations related to the description of overland flow on plane soil surface are pointed out. Finally, an application to a nonplanar natural surface of 75 m 2 illustrated the distribution of erosion and sedimentation over the plot.

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“…[65] Rates k 41 and k 32 are assumed to be zero due to an assumption that neither freely suspended microorganisms nor microorganisms attached to fine sediments settle once entrained in the flow [Sander et al, 1996;Medema et al, 1998]. …”

Section: Parameter Estimation From Experimental Datamentioning

confidence: 99%

A combined microscopic and macroscopic approach to modeling the transport of pathogenic microorganisms from nonpoint sources of pollution

Yeghiazarian

Walker

Binning

et al. 2006

Water Resources Research

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[1] Recent outbreaks of cryptosporidiosis raise serious concerns about the effectiveness of watershed management in controlling the risk of contamination by pathogens. A modeling strategy that takes into account the inherent randomness of the occurrence and transport of pathogens in surface water is important for accurate risk assessment and prediction of water contamination events. This paper presents a stochastic Markov model of microorganism transport, with distinct states of microorganism behavior capturing the microbial partitioning between solid and aqueous phases in runoff and soil surface, including the partitioning among soil particles of various sizes. A connection between the soil sediment and microbial transport is established through the incorporation of an erosion model (WEPP) into the microorganism transport model. Probability distribution functions of microorganism occurrence in time and space are constructed, and their properties are analyzed. A deterministic mathematical model of coupled pathogen and sediment transport is developed in parallel to parameterize the Markov process. The numerical values for the Markov model parameters were derived from two sets of experimental data. Model results show that areas with clay soils are more likely than sandy soils to contribute to contamination events and that the most influential transport parameters are the saturated hydraulic conductivity, rainfall intensity, and topographic slope.

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Unsteady soil erosion model, analytical solutions and comparison with experimental results

Cited by 74 publications

References 9 publications

Suspended sediment concentration–discharge relationships in the (sub-) humid Ethiopian highlands

Suspended sediment concentration–discharge relationships in the (sub-) humid Ethiopian highlands

PSEM_2D: A physically based model of erosion processes at the plot scale

A combined microscopic and macroscopic approach to modeling the transport of pathogenic microorganisms from nonpoint sources of pollution

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