The Experts below are selected from a list of 26679 Experts worldwide ranked by ideXlab platform
Jeanyves Parlange - One of the best experts on this subject based on the ideXlab platform.
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Modeling simple experiments of biochar erosion from soil
Journal of Hydrology, 2013Co-Authors: Chaozi Wang, M T Walter, Jeanyves ParlangeAbstract:Summary Biochar is often promoted as an amendment to improve soil quality. However, researchers have recently noted that biochar and similar substances preferentially erode from soil, which may reduce its effectiveness. Identifying the erosion mechanisms may help develop strategies for retaining biochar in soil. To investigate the role of raindrop impact biochar erosion, we applied the Hairsine–Rose erosion Model to small-scale experiments that simulated rainfall on a simple biochar-soil mixture. The Hairsine–Rose Model simulated the biochar concentrations in runoff well for the early part of the experiments but under-predicted the concentrations for longer times. At the end of the simulated rainfall experiments, biochar content in the soil increased with depth in the soil column from 1% near the surface to 8% in underlying soil layers; similar distributions have been observed for soil, which drives upwards diffusion. By superimposing the Wallach diffusion Model on the Hairsine–Rose Model we were able to simulate biochar concentrations at both short and long times. We speculate that the relatively dense sand particles are displacing the biochar and we are investigating this further. Our findings suggest that long-term sequestration of biochar in soil is unlikely in soils or parts of the landscape with limited infiltration capacity.
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Erosion of soils due to rainfall impact – an interpolation method
Ecohydrology, 2012Co-Authors: Jeanyves Parlange, W L Hogarth, G. C. Sander, P. B. Hairsine, Seifeddine Jomaa, David Andrew Barry, B. C. P. Heng, Alessandro Brovelli, Marc B. Parlange, Tammo S SteenhuisAbstract:An approximate analytical solution of the Hairsine-Rose Model of erosion is obtained by interpolation of asymptotic expressions for large times and great distances. The solution, when erosion is initiated by rainfall impact, is both simple and accurate. The results are illustrated by comparison with a numerical solution.
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effect of raindrop splash and transversal width on soil erosion laboratory flume experiments and analysis with the hairsine Rose Model
Journal of Hydrology, 2010Co-Authors: Seifeddine Jomaa, Jeanyves Parlange, B. C. P. Heng, Alessandro Brovelli, D A Barry, G C Sander, H Trompvan J MeerveldAbstract:The parameter consistency of the one-dimensional Hairsine-Rose (H-R) erosion Model under conditions of significant rainfall splash was examined. To account for the splash characteristic length scale and its interaction with the transverse erosion width, experiments were carried out using erosion flumes of the same length (6 m), but different widths, with sediment concentrations measured at the flume exits. Total sediment concentration and the concentration of seven size fractions ( 1000 µm) were measured at high rainfall intensity (60 mm/h) and with a gentle slope (2.2%). The conditions employed ensured that erosion was predominantly precipitation-driven. The experimental results showed that raindrop splash affected particularly the sediment breakthrough from the wider flumes (flumes 1 and 2, 1- and 0.5-m wide, respectively). However, the raindrop splash effect was less significant in observed sediment concentrations from the narrower flumes (flumes 3 and 4, both 0.25-m wide). For these flumes, the detached sediment was affected by the transversal width of the flume in that an amount of detached sediment adhered to the barriers instead of being removed in the overland flow. The one-dimensional H-R Model was fitted to the experimental results and good agreement was found, in particular for the finer size classes. The data for the coarser grain sizes were more scattered, suggesting sediment motion by mechanisms other than as a suspension in the overland flow (e.g., rolling along the soil surface). The optimized parameters indicated that the shield layers (where the shield consists of redeposited eroded sediment) of the wider flumes (1 and 2) developed within 5-10 min from the start of the experiment, whereas in the narrower flumes (3 and 4) they never fully developed. The optimized detachment rates were consistent with previous findings, but the estimated thickness of the deposited layer was too small to provide complete protection of the original soil against raindrop detachment, indicating that the shield was not uniform. The experimental design allowed us to investigate directly the effect of flow non-uniformity on soil erosion by inclusion of an offset drainage point in flume 4. The observations taken during and after the experiment, as well as surface elevation data, confirmed the noticeable impact of non-uniform flow on the erosion process.
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investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h 21 . Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify. q 2003 Elsevier Science B.V. All rights reserved.
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Investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h−1. Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify
W L Hogarth - One of the best experts on this subject based on the ideXlab platform.
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Erosion of soils due to rainfall impact – an interpolation method
Ecohydrology, 2012Co-Authors: Jeanyves Parlange, W L Hogarth, G. C. Sander, P. B. Hairsine, Seifeddine Jomaa, David Andrew Barry, B. C. P. Heng, Alessandro Brovelli, Marc B. Parlange, Tammo S SteenhuisAbstract:An approximate analytical solution of the Hairsine-Rose Model of erosion is obtained by interpolation of asymptotic expressions for large times and great distances. The solution, when erosion is initiated by rainfall impact, is both simple and accurate. The results are illustrated by comparison with a numerical solution.
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investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h 21 . Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify. q 2003 Elsevier Science B.V. All rights reserved.
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Investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h−1. Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify
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Testing a mechanistic soil erosion Model with a simple experiment
Journal of Hydrology, 2001Co-Authors: A. Heilig, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, C W Rose, W L Hogarth, D. Debruyn, G. C. Sander, P. B. Hairsine, Larry P. WalkerAbstract:A simple experiment was used to test the development of a “shield” over the original soil and associated changes in sediment concentrations as described in the mechanistic Rose erosion Model. The Rose Model, developed for rain-induced erosion and sediment transport on hillslopes (J. Hydrol., 217 (1999) 149; Trends Hydrol., 1 (1994) 443), was applied to a simple experimental set-up, consisting of a small horizontal soil surface (7 £ 7c m 2 ) under constant shallow (5 mm) overland flow with raindrop impact. The soil consisted of two particle size classes, clay and sand, greatly simplifying the analytical solution of the Rose Model by reducing the unknown system parameters to one, the soil detachability. Photographic documentation of shield formation corroborated the conceptual validity of the Rose Model. Using a single, best-fit value for the soil detachability, quantitative agreement between Modeled and experimental results is excellentOR 2 a 0:9U: This research provides lucidity to the primary processes enveloped in the Rose Model and these mechanisms can be extrapolated to more complicated or realistic systems in which the individual processes may be more difficult to recognize. q 2001 Elsevier Science B.V. All rights reserved.
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Soil Erosion Processes: Laboratory Observations and Modeling
Soil Erosion, 1Co-Authors: Jeanyves Parlange, Tammo S Steenhuis, M T Walter, W L Hogarth, A. Heilig, D. Debruyn, C. A. Rose, G. C. Sander, P. B. Hairsine, J. C. AscoughAbstract:The mechanistic Rose Model for rain-induced erosion and sediment transport on hillslopes was tested for a simple experimental study, consisting of a small horizontal soil surface under constant shallow overland flow with raindrop impact. The soil consisted of two particle size classes, clay and sand, greatly simplifying the analytical solution of the Rose Model reducing the unknown system parameters to one, the soil detachability. Photographic documentation of shield formation corroborated the conceptual validity of the Rose Model and illustrated very clearly the primary processes involved.
Andrey Shilnikov - One of the best experts on this subject based on the ideXlab platform.
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Macro- and micro-chaotic structures in the Hindmarsh-Rose Model of bursting neurons
Chaos (Woodbury N.Y.), 2014Co-Authors: Roberto Barrio, M. Angeles Martínez, Sergio Serrano, Andrey ShilnikovAbstract:We study a plethora of chaotic phenomena in the Hindmarsh-Rose neuron Model with the use of several computational techniques including the bifurcation parameter continuation, spike-quantification, and evaluation of Lyapunov exponents in bi-parameter diagrams. Such an aggregated approach allows for detecting regions of simple and chaotic dynamics, and demarcating borderlines—exact bifurcation curves. We demonstrate how the organizing centers—points corresponding to codimension-two homoclinic bifurcations—along with fold and period-doubling bifurcation curves structure the biparametric plane, thus forming macro-chaotic regions of onion bulb shapes and revealing spike-adding cascades that generate micro-chaotic structures due to the hysteresis.
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Parameter-sweeping techniques for temporal dynamics of neuronal systems: case study of Hindmarsh-Rose Model
The Journal of Mathematical Neuroscience, 2011Co-Authors: Roberto Barrio, Andrey ShilnikovAbstract:Background Development of effective and plausible numerical tools is an imperative task for thorough studies of nonlinear dynamics in life science applications. Results We have developed a complementary suite of computational tools for two-parameter screening of dynamics in neuronal Models. We test a ‘brute-force’ effectiveness of neuroscience plausible techniques specifically tailored for the examination of temporal characteristics, such duty cycle of bursting, interspike interval, spike number deviation in the phenomenological Hindmarsh-Rose Model of a bursting neuron and compare the results obtained by calculus-based tools for evaluations of an entire spectrum of Lyapunov exponents broadly employed in studies of nonlinear systems. Conclusions We have found that the results obtained either way agree exceptionally well, and can identify and differentiate between various fine structures of complex dynamics and underlying global bifurcations in this exemplary Model. Our future planes are to enhance the applicability of this computational suite for understanding of polyrhythmic bursting patterns and their functional transformations in small networks.
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parameter sweeping techniques for temporal dynamics of neuronal systems case study of hindmarsh Rose Model
The Journal of Mathematical Neuroscience, 2011Co-Authors: Roberto Barrio, Andrey ShilnikovAbstract:Background Development of effective and plausible numerical tools is an imperative task for thorough studies of nonlinear dynamics in life science applications.
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Techniques for temporal dynamics of neuronal systems: the Hindmarsh-Rose Model
2011Co-Authors: Roberto Barrio, Andrey ShilnikovAbstract:A phenomenological system of ODEs proposed by Hindmarsh and Rose [2] for Modeling bursting and spiking oscillatory activities in isolated neurons is given by: _ x = y ax 3 + bx 2 z + I;
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METHODS OF THE QUALITATIVE THEORY FOR THE HINDMARSH–Rose Model: A CASE STUDY – A TUTORIAL
International Journal of Bifurcation and Chaos, 2008Co-Authors: Andrey Shilnikov, Marina L. KolomietsAbstract:Homoclinic bifurcations of both equilibria and periodic orbits are argued to be critical for understanding the dynamics of the Hindmarsh–Rose Model in particular, as well as of some square-wave bursting Models of neurons of the Hodgkin–Huxley type. They explain very well various transitions between the tonic spiking and bursting oscillations in the Model. We present the approach that allows for constructing Poincare return mapping via the averaging technique. We show that a modified Model can exhibit the blue sky bifurcation, as well as, a bistability of the coexisting tonic spiking and bursting activities. A new technique for localizing a slow motion manifold and periodic orbits on it is also presented.
Tammo S Steenhuis - One of the best experts on this subject based on the ideXlab platform.
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Erosion of soils due to rainfall impact – an interpolation method
Ecohydrology, 2012Co-Authors: Jeanyves Parlange, W L Hogarth, G. C. Sander, P. B. Hairsine, Seifeddine Jomaa, David Andrew Barry, B. C. P. Heng, Alessandro Brovelli, Marc B. Parlange, Tammo S SteenhuisAbstract:An approximate analytical solution of the Hairsine-Rose Model of erosion is obtained by interpolation of asymptotic expressions for large times and great distances. The solution, when erosion is initiated by rainfall impact, is both simple and accurate. The results are illustrated by comparison with a numerical solution.
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investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h 21 . Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify. q 2003 Elsevier Science B.V. All rights reserved.
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Investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h−1. Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify
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Testing a mechanistic soil erosion Model with a simple experiment
Journal of Hydrology, 2001Co-Authors: A. Heilig, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, C W Rose, W L Hogarth, D. Debruyn, G. C. Sander, P. B. Hairsine, Larry P. WalkerAbstract:A simple experiment was used to test the development of a “shield” over the original soil and associated changes in sediment concentrations as described in the mechanistic Rose erosion Model. The Rose Model, developed for rain-induced erosion and sediment transport on hillslopes (J. Hydrol., 217 (1999) 149; Trends Hydrol., 1 (1994) 443), was applied to a simple experimental set-up, consisting of a small horizontal soil surface (7 £ 7c m 2 ) under constant shallow (5 mm) overland flow with raindrop impact. The soil consisted of two particle size classes, clay and sand, greatly simplifying the analytical solution of the Rose Model by reducing the unknown system parameters to one, the soil detachability. Photographic documentation of shield formation corroborated the conceptual validity of the Rose Model. Using a single, best-fit value for the soil detachability, quantitative agreement between Modeled and experimental results is excellentOR 2 a 0:9U: This research provides lucidity to the primary processes enveloped in the Rose Model and these mechanisms can be extrapolated to more complicated or realistic systems in which the individual processes may be more difficult to recognize. q 2001 Elsevier Science B.V. All rights reserved.
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Soil Erosion Processes: Laboratory Observations and Modeling
Soil Erosion, 1Co-Authors: Jeanyves Parlange, Tammo S Steenhuis, M T Walter, W L Hogarth, A. Heilig, D. Debruyn, C. A. Rose, G. C. Sander, P. B. Hairsine, J. C. AscoughAbstract:The mechanistic Rose Model for rain-induced erosion and sediment transport on hillslopes was tested for a simple experimental study, consisting of a small horizontal soil surface under constant shallow overland flow with raindrop impact. The soil consisted of two particle size classes, clay and sand, greatly simplifying the analytical solution of the Rose Model reducing the unknown system parameters to one, the soil detachability. Photographic documentation of shield formation corroborated the conceptual validity of the Rose Model and illustrated very clearly the primary processes involved.
M T Walter - One of the best experts on this subject based on the ideXlab platform.
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Modeling simple experiments of biochar erosion from soil
Journal of Hydrology, 2013Co-Authors: Chaozi Wang, M T Walter, Jeanyves ParlangeAbstract:Summary Biochar is often promoted as an amendment to improve soil quality. However, researchers have recently noted that biochar and similar substances preferentially erode from soil, which may reduce its effectiveness. Identifying the erosion mechanisms may help develop strategies for retaining biochar in soil. To investigate the role of raindrop impact biochar erosion, we applied the Hairsine–Rose erosion Model to small-scale experiments that simulated rainfall on a simple biochar-soil mixture. The Hairsine–Rose Model simulated the biochar concentrations in runoff well for the early part of the experiments but under-predicted the concentrations for longer times. At the end of the simulated rainfall experiments, biochar content in the soil increased with depth in the soil column from 1% near the surface to 8% in underlying soil layers; similar distributions have been observed for soil, which drives upwards diffusion. By superimposing the Wallach diffusion Model on the Hairsine–Rose Model we were able to simulate biochar concentrations at both short and long times. We speculate that the relatively dense sand particles are displacing the biochar and we are investigating this further. Our findings suggest that long-term sequestration of biochar in soil is unlikely in soils or parts of the landscape with limited infiltration capacity.
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investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h 21 . Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify. q 2003 Elsevier Science B.V. All rights reserved.
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Investigating ponding depth and soil detachability for a mechanistic erosion Model using a simple experiment
Journal of Hydrology, 2003Co-Authors: Bin Gao, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, K Nakano, C W Rose, W L HogarthAbstract:This work extends the simple experimental studies initiated by Heilig et al. [J. Hydrol. 244(2001) 9] to study erosion processes inherent to a mechanistic soil erosion Model (the Rose Model) that were not addressed in earlier studies. Specifically, we investigated the impacts of ponding water depth and soil detachability on erosion. The Rose Model describes the interplay among the processes of soil detachment, transport, deposition, and redetachment, which are involved in rain-induced soil erosion and sediment transport. The simple experiment that was used to improve our understanding of how water-ponding and soil detachability affect soil erosion utilized a small, horizontal, uniform, soil surface exposed to uniform, simulated rainfall. Rainfall rates were systematically changed between 6 and 48 mm h−1. Soil detachability was associated with a clay soil prepared at two different water contents. The Rose Model was applied to the experimental conditions and the predicted erosion behavior was compared to experimental measurements. Observed data compared very well with the Model results. The experimentally observed relationship between ponding water depth and soil detachability agreed well with previously proposed theories; soil detachability was constant for ponding depths below a critical depth and dramatically decreased above the critical depth. Also, these experiments corroborated that the soil detachability as represented in the Rose Model is independent of rain intensity. These results provide support to the validity of the Rose Model with respect to the roles of surface water-ponding and its relationship to soil detachability. These mechanisms can be incorporated into Models of more complicated and realistic systems in which these individual processes may be difficult to explicitly identify
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Testing a mechanistic soil erosion Model with a simple experiment
Journal of Hydrology, 2001Co-Authors: A. Heilig, Tammo S Steenhuis, M T Walter, Jeanyves Parlange, C W Rose, W L Hogarth, D. Debruyn, G. C. Sander, P. B. Hairsine, Larry P. WalkerAbstract:A simple experiment was used to test the development of a “shield” over the original soil and associated changes in sediment concentrations as described in the mechanistic Rose erosion Model. The Rose Model, developed for rain-induced erosion and sediment transport on hillslopes (J. Hydrol., 217 (1999) 149; Trends Hydrol., 1 (1994) 443), was applied to a simple experimental set-up, consisting of a small horizontal soil surface (7 £ 7c m 2 ) under constant shallow (5 mm) overland flow with raindrop impact. The soil consisted of two particle size classes, clay and sand, greatly simplifying the analytical solution of the Rose Model by reducing the unknown system parameters to one, the soil detachability. Photographic documentation of shield formation corroborated the conceptual validity of the Rose Model. Using a single, best-fit value for the soil detachability, quantitative agreement between Modeled and experimental results is excellentOR 2 a 0:9U: This research provides lucidity to the primary processes enveloped in the Rose Model and these mechanisms can be extrapolated to more complicated or realistic systems in which the individual processes may be more difficult to recognize. q 2001 Elsevier Science B.V. All rights reserved.
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Soil Erosion Processes: Laboratory Observations and Modeling
Soil Erosion, 1Co-Authors: Jeanyves Parlange, Tammo S Steenhuis, M T Walter, W L Hogarth, A. Heilig, D. Debruyn, C. A. Rose, G. C. Sander, P. B. Hairsine, J. C. AscoughAbstract:The mechanistic Rose Model for rain-induced erosion and sediment transport on hillslopes was tested for a simple experimental study, consisting of a small horizontal soil surface under constant shallow overland flow with raindrop impact. The soil consisted of two particle size classes, clay and sand, greatly simplifying the analytical solution of the Rose Model reducing the unknown system parameters to one, the soil detachability. Photographic documentation of shield formation corroborated the conceptual validity of the Rose Model and illustrated very clearly the primary processes involved.
