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Автор: Grafiati
Опубліковано: 10 грудня 2022
Оновлено: 29 січня 2023

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Статті в журналах з теми "Soil erosion Computer simulation"

1

Littleboy, M., DM Silburn, DM Freebairn, DR Woodruff, GL Hammer, and JK Leslie. "Impact of soil erosion on production in cropping systems .I. Development and validation of a simulation model." Soil Research 30, no. 5 (1992): 757. http://dx.doi.org/10.1071/sr9920757.

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A computer simulation model to analyse risks of soil erosion to long-term crop production is described. The model, called PERFECT, simulates interactions between soil type, climate, fallow management strategy and crop sequence. It contains six main modules; data input, water balance, crop growth, crop residue, erosion and model output. Modules are arranged in a framework that allows alternative modules to be used as required for the potential range of applications. The model contains dynamic crop growth models for wheat, sorghum and sunflower. Validation of PERFECT against small catchment and contour bay data collected throughout Queensland showed that PERFECT explained up to 84% of the variation in total available soil water, 89% of the variation in daily runoff, and up to 75% of the variation in grain yield. Average annual soil erosion was accurately predicted but daily erosion totals were less accurate due to the exclusion of rainfall intensity in erosion prediction. Variability in climate dominates agricultural production in the subtropical region of Australia. The validated model can be coupled with long-term climate and soils databases to simulate probabilities of production and erosion risks due to climatic variability. It provides a method to determine the impact of soil erosion on long-term productivity.
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Kinnell, P. I. A. "Influence of surface zones with zero detachment on erosion by rain-impacted flow." Soil Research 36, no. 2 (1998): 327. http://dx.doi.org/10.1071/s97047.

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Zones of zero detachment occur on the soil surface when cryptogamic cover protects the soil surface from erosion by rain-impacted flow. The effect of spatial variation in the distribution of these zones was examined through a computer simulation of erosion by rain-impacted flow on small (0·5-m-long) surfaces. The results from the simulations indicate that the effect of spatial variations in cryptogam cover decreases as the susceptibility of the exposed surfaces to detachment by rain-impacted flow increases. They also indicate that when the sediment being transported is dominated by fine particles, the effect of the cover on erosion will be more closely related to the average cover than when the sediment is dominated by coarse particles.
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Wang, Xu, Makoto Fujisawa, and Masahiko Mikawa. "Visual Simulation of Soil-Structure Destruction with Seepage Flows." Proceedings of the ACM on Computer Graphics and Interactive Techniques 4, no. 3 (September 22, 2021): 1–18. http://dx.doi.org/10.1145/3480141.

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This paper introduces a method for simulating soil-structure coupling with water, which involves a series of visual effects, including wet granular materials, seepage flows, capillary action between grains, and dam breaking simulation. We develop a seepage flow based SPH-DEM framework to handle soil and water particles interactions through a momentum exchange term. In this framework, water is seen as a seepage flow through porous media by Darcy's law; the seepage rate and the soil permeability are manipulated according to drag coefficient and soil porosity. A water saturation-based capillary model is used to capture various soil behaviors such as sandy soil and clay soil. Furthermore, the capillary model can dynamically adjust liquid bridge forces induced by surface tension between soil particles. The adhesion model describes the attraction ability between soil surfaces and water particles to achieve various visual effects for soil and water. Lastly, this framework can capture the complicated dam-breaking scenarios caused by overtopping flow or internal seepage erosion that are challenging to simulate.
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4

Cao, Chendi, and Mitchell Neilsen. "Dam Breach Simulation with the Material Point Method." Computation 9, no. 2 (January 20, 2021): 8. http://dx.doi.org/10.3390/computation9020008.

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Dam embankment breaches caused by overtopping or internal erosion can impact both life and property downstream. It is important to accurately predict the amount of erosion, peak discharge, and the resulting downstream flow. This paper presents a new model based on the material point method to simulate soil and water interaction and predict failure rate parameters. The model assumes that the dam consists of a homogeneous embankment constructed with cohesive soil, and water inflow is defined by a hydrograph using other readily available reach routing software. The model uses continuum mixture theory to describe each phase where each species individually obeys the conservation of mass and momentum. A two-grid material point method is used to discretize the governing equations. The Drucker–Prager plastic flow model, combined with a Hencky strain-based hyperelasticity model, is used to compute soil stress. Water is modeled as a weakly compressible fluid. Analysis of the model demonstrates the efficacy of our approach for existing examples of overtopping dam breach, dam failures, and collisions. Simulation results from our model are compared with a physical-based breach model, WinDAM C. The new model can capture water and soil interaction at a finer granularity than WinDAM C. The new model gradually removes the granular material during the breach process. The impact of material properties on the dam breach process is also analyzed.
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Honek, David, Zuzana Németová, Silvia Kohnová, and Monika Šulc Michalková. "Sensitivity analysis of soil parameters and their impact on runoff-erosion processes." Pollack Periodica 15, no. 1 (April 2020): 53–64. http://dx.doi.org/10.1556/606.2020.15.1.6.

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Abstract The modeling of soil erosion processes is affected by several factors that reflect the physical-geographic conditions of the study site together with the land use linkage. The soil parameters are significant in the modeling of erosion and also runoff processes. The correct determination of a soil's parameters becomes a crucial part of the model's calibration. This paper deals with a sensitivity analysis of seven soil input parameters to the physically-based Erosion 3D model. The results show the variable influence of each soil parameter. The Erosion 3D model is very sensitive to initial soil moisture, bulk density, and erodibility.
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Gonzales, Howell B., John Tatarko, Mark E. Casada, Ronaldo G. Maghirang, Lawrence J. Hagen, and Charles J. Barden. "Computational Fluid Dynamics Simulation of Airflow through Standing Vegetation." Transactions of the ASABE 62, no. 6 (2019): 1713–22. http://dx.doi.org/10.13031/trans.13449.

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Abstract. Maintaining vegetative cover on the soil surface is the most widely used method for control of soil loss by wind erosion. We numerically modeled airflow through artificial standing vegetation (i.e., simulated wheat plants) using computational fluid dynamics (CFD). A solver (simpleFoam within the OpenFOAM software architecture) was used to simulate airflow through various three-dimensional (3D) canopy structures in a wind tunnel, which were created using another open-source CAD geometry software (Salomé ver. 7.2). This study focused on two specific objectives: (1) model airflow through standing vegetation using CFD, and (2) compare the results of a previous wind tunnel study with various artificial vegetation configurations to the results of the CFD model. Wind speeds measured in the wind tunnel experiment differed slightly from the numerical simulation using CFD, especially near positions where simulated vegetation was present. Effective drag coefficients computed using wind profiles did not differ significantly (p <0.05) between the experimental and simulated results. Results of this study will provide information for research into other types of simulated stubble or sparse vegetation during wind erosion events.HighlightsMeasured airflow through a simulated canopy was successfully modeled using CFD software.Effective drag coefficients did not differ between the experimental and simulated results.Results of this study provide 3-D simulation data of wind flow through a plant canopy. Keywords: 3-D canopy structure, OpenFOAM, Wind erosion, Wind tunnel studies.
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7

Majumdar, S., S. Shukla, and A. Maiti. "OPEN AGENT BASED RUNOFF AND EROSION SIMULATION (OARES): A GENERIC CROSS PLATFORM TOOL FOR SPATIO-TEMPORAL WATERSHED MONITORING USING CLIMATE FORECAST SYSTEM REANALYSIS WEATHER DATA." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-4 (September 19, 2018): 125–32. http://dx.doi.org/10.5194/isprs-annals-iv-4-125-2018.

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<p><strong>Abstract.</strong> The aim of this study is to explore the applicability of Agent Based Modelling (ABM) for the simulation of rainfall runoff and soil erosion used in a watershed monitoring activity. The study utilizes Landsat 8 imagery for Land Use Land Cover (LULC) map generation, ASTER DEM for obtaining elevation information and Climate Forecast System Reanalysis (CFSR) 36 year weather data of Asan watershed, Uttarakhand, India. In the proposed model, four major agents (raindrops, soil, elevation and water amount) have been defined for estimating the soil erosion in the region. Moreover, the direct runoff has been simulated using the Soil Conservation Service (SCS) method. The analysis of the entire time series using this approach shows that there have been substantial changes in the rainfall runoff pattern primarily due to the varying environmental conditions of the study area since the late 1980s. Furthermore, a rough estimate of the soil erosion and deposition in the area have been computed which is aligned with the theory of sediment transport and deposition. In order to automate the entire model workflow, an open source cross platform tool has been developed using Python, R and NetLogo libraries. The Open Agent Based Runoff and Erosion Simulation (OARES) tool incorporates a generic interface for analysing large spatio-temporal datasets in watershed studies. The overall analysis concludes that the results obtained using ABM are comparable to that of the conventional hydrological models, and henceforth, ABM could be utilized as a future potential hydrological modelling paradigm.</p>
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WALL, G. J., W. T. DICKINSON, R. P. RUDRA, and D. R. COOTE. "SEASONAL SOIL ERODIBILITY VARIATION IN SOUTHWESTERN ONTARIO." Canadian Journal of Soil Science 68, no. 2 (May 1, 1988): 417–24. http://dx.doi.org/10.4141/cjss88-038.

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A study was conducted to evaluate the potential seasonal variation in soil erodibility (K) for selected soils of southwestern Ontario. Field-plot data, laboratory flume/rainfall-simulator studies, and a K-factor prediction equation were used to assess the potential magnitude of the seasonal variation of soil erodibility. Field-plot studies for a Guelph loam soil revealed that values were highest in the winter-spring thaw period (March) with a ratio of K seasonal to K annual (Kc) of 10. Laboratory flume and rainfall simulations with Fox sand, Haldimand silty clay, and Colwood silt loam soils were conducted with soil moisture and internal drainage varied to simulate seasonal conditions. The results corresponded with those observed in the field study, with highest K values occurring under simulated winter-spring thaw conditions (values of Kc =.4 – 4.0) and lowest values under simulated summer conditions (Kc < 1). Seasonal K values were computed with a prediction equation for 17 soil textural classes. Soil structure and permeability parameters of the prediction equation were modified to reflect seasonal variability in these properties. The predicted Kc values were highest for the winter-spring thaw period and approximately equal for the spring and summer periods. Results indicate that soil erodibility varies significantly with seasonal soil conditions and the magnitude of seasonal differences changes with soil textures. Key words: Soil erodibility, field-plot erosion data, rainfall simulation, runoff flume
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Er Nas, Sibel, and Muammer Çalık. "A CROSS-AGE COMPARISON OF SCIENCE STUDENT TEACHERS’ CONCEPTUAL UNDERSTANDING OF SOIL EROSION." Problems of Education in the 21st Century 76, no. 5 (October 15, 2018): 601–19. http://dx.doi.org/10.33225/pec/18.76.601.

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The relevant literature has shown that student teachers hold alternative conceptions of soil erosion. Even though Turkish science student teachers are expected to teach the concept of ‘soil erosion’ in lower secondary schools (grades 5-8), none of the earlier studies have explored their conceptual growth and/or mental models throughout a 4-year undergraduate program. Indeed, science (student) teachers, who play a pivotal role in teaching the sustainability of soil as an environmental heritage, are able to transfer their environmental knowledge and mental models to younger generations. Therefore, the aim of this research was to elicit science student teachers’ (SSTs) understanding of soil erosion. In a cross-age comparison, the sample of the research was comprised of the first-year (n=54), second-year (n=62), third-year (n=60), and fourth-year of a four-year science education program (n=65), a total of 241 SSTs, enrolled at the Department of Science Education in Karadeniz Technical University in Turkey. A questionnaire with 4 open-ended questions and semi-structured interviews were used to collect data. The results indicated that the majority of the SSTs confused the concept of ‘soil erosion’ with the one ‘landslide’. For this reason, the current research suggests the development of analogies and computer simulations to overcome this confusion. Keywords: conceptual understanding, cross-age, mental model, science student teacher, soil erosion.
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Jiménez-Hornero, F. J., J. V. Giráldez, A. M. Laguna, and J. E. Jiménez-Hornero. "An educational computer tool for simulating long-term soil erosion on agricultural landscapes." Computer Applications in Engineering Education 17, no. 3 (September 2009): 253–62. http://dx.doi.org/10.1002/cae.20193.

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Дисертації з теми "Soil erosion Computer simulation"

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Gunawardena, E. R. N. "Computer simulation of runoff and soil erosion from small agricultural catchments in Sri Lanka." Thesis, Cranfield University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333925.

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Geng, Guoqiang. "A simulation study of soil erosion by snowmelt and spring rainfall." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28449.

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High rates of runoff and soil loss occur in temperate areas in late winter and early spring. A low-intensity rainfall simulator and a snowmelt simulator were developed to study soil erosion by snowmelt and/or spring rainfall on a sandy loam soil of southern Quebec. Erosive agent, land slope, thaw depth of partly frozen soil, and intensity and duration of the event were studied in the laboratory using the simulators. All these factors had significant effects on soil erosion. Sediment concentration, soil loss rate, and total soil loss increased with increasing land slope, thaw depth, and intensity, duration, and impact energy of the erosive agent. Duration showed a significant interaction with each of the other factors. interaction between thaw depth and intensity of the event was significant under both snowmelt and rainfall simulation, whereas interaction between land slope and intensity was significant under rainfall simulation, but not under snowmelt simulation. Erosive agent also interacted with each of the other factors. All these interactions increased soil loss. The presence of a frozen sublayer interacted with the other factors and greatly increased runoff, sediment concentration and total soil loss. Rainfall caused more soil loss than did snowmelt under the same conditions.
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Bobe, Bedadi Woreka. "Evaluation of soil erosion in the Harerge region of Ethiopia using soil loss models, rainfall simulation and field trails." Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-08022004-141533.

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Parker, Ronald Dean 1948. "The effect of spatial variability on output from the water erosion prediction project soil erosion computer model." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/191165.

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Spatial variability is all that stands between hydrology and science, forcing us to deal in probabilities and averages. Because of scale, we can not consider forces on individual soil particles, water molecules and solute ions when addressing human size problems. We must therefore look at aggregate properties and mean values for parameters and inputs in computer modeling of hydrologic phenomena. This research explores the impact of spatially variable inputs on the Water Erosion Prediction Project soil erosion computer program. Distributions of input variables are generated and assigned randomly to a grid of homogeneous rangeland hillslope elements. Values for runoff volume and sediment loss from each flow path are recorded and averaged to provide a distribution of outputs in the form of a sensitivity analysis. Variabilities of slope, slope length, soil textures, soil characteristics, terrain, convex and concave slopes, soil saturation, rainfall amount and vegetation were examined. Results show that use of mean inputs values in the WEPP representative hillslope model yields very similar outputs to the spatially variable research model using a distribution of inputs in all simulations in the case of totally random bare rangeland soils. When a decreasing trend in soil clay content is introduced in the variable model, the hillslope model using average values as inputs no longer provides a good estimate of the sediment loss. When random vegetation is generated and added to the simulation, runoff volume continues to be similar between the two models, but the sediment loss is much higher in the spatially variable model. In addition, the results of the standard hillslope model are much less responsive to changes in slope than those of the spatially variable model. It is concluded that spatial variability of soils must be considered when there is a linear change in input values with slope position. Likewise spatial variability of vegetation needs to be addressed in order to accurately estimate erosion on the rangeland watersheds considered in this dissertation. It is also found that this type of simulation provides a model for sensitivity analysis of a complex computer programs. Physically related inputs can be generated in such a way as to preserve the desired interrationships and distributions of inputs can be directly compared to generated distributions of outputs.
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Bussen, Patrick. "Analysis of a rapid soil erosion assessment tool." Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/2351.

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Michaud, Aubert Raymond. "Soil erodibility indices for Southern Quebec soils derived under variable intensity rainfall simulation." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66178.

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Bobe, Bedadi Woreka. "Evaluation of soil erosion in the Harerge region of Ethiopia using soil loss models, rainfall simulation and field trials." Thesis, University of Pretoria, 2004. http://hdl.handle.net/2263/26929.

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Accelerated soil erosion is one of the major threats to agricultural production in Ethiopia and the Harerge region is not exceptional. It is estimated that about 1.5 billion tones of soil is being eroded every year in Ethiopia. In the extreme cases, especially for the highlands, the rate of soil loss is estimated to reach up to 300 t ha-1yr-1 with an average of about 70 t ha -1yr-1 which is beyond any tolerable level. The government have made different attempts to avert the situation since 1975 through initiation of a massive program of soil conservation and rehabilitation of severely degraded lands. Despite considerable efforts, the achievements were far bellow expectations. This study was aimed at assessing the effect of some soil properties, rainfall intensity and slope gradients on surface sealing, soil erodibility, runoff and soil loss from selected sites in the Harerge region, eastern Ethiopia, using simulated rainfall. Soil loss was also estimated for the sites using Soil Loss Estimation Model for Southern Africa (SLEMSA) and the Universal soil Loss Equation (USLE). Moreover, the effectiveness of various rates and patterns of wheat residue mulching in controlling soil loss was also evaluated for one of the study sites, (i.e. Regosol of Alemaya University), under both rainfall simulation and field natural rainfall conditions. For most of the erosion parameters, the interaction among soil texture, slope gradient and rainfall intensity was significant. In general however, high rainfall intensity induced high runoff, sediment yield and splash. The effect of slope gradients on most of the erosion parameters was not significant as the slope length was too small to bring about a concentrated flow. The effect of soils dominated by any one of the three soil separates on the erosion parameters was largely dependent on rainfall intensity and slope gradient. The soils form the 15 different sites in Harerge showed different degrees of vulnerability to surface sealing, runoff and sediment yield. These differences were associated with various soil properties. Correlation of soil properties to the erosion parameters revealed that aggregate stability was the main factor that determined the susceptibility of soils to sealing, runoff and soil loss. This was in turn affected by organic carbon content, percent clay and exchangeable sodium percentage (ESP). Soils with relatively high ESP such as those at Babile (13.85) and Gelemso (7.18) were among the lowest in their aggregate stability (percent water stable aggregates of 0.25 –2.0mm diameter); and have highest runoff and sediment yield as compared to other soils in the study. Similarly, most of those soils with relatively low ESP, high organic carbon content (OC%) and high water stable aggregates such as Hamaressa, AU (Alemaya University) vertisol and AU regosol were among the least susceptible to sealing and interrill erosion. Nevertheless, some exceptions include soils like those of Hirna where high runoff was recorded whilst having relatively high OC%, low ESP and high water stable aggregates. Both the SLEMSA and USLE models were able to identify the erosion hazards for the study sites. Despite the differences in the procedures of the two models, significant correlation (r = 0.87) was observed between the values estimated by the two methods. Both models estimated higher soil loss for Gelemso, Babile, Karamara and Hamaressa. Soil loss was lower for Diredawa, AU-vertisol and AU-Alluvial all of which occur on a relatively low slope gradients. The high soil loss for Babile and Gelemso conforms with the relative soil erodibility values obtained under rainfall simulation suggesting that soil erodibility, among others, is the main factor contributing to high soil loss for these soils. The difference in the estimated soil losses for the different sites was a function of the interaction of the various factors involved. Though the laboratory soil erodibility values were low to medium for Hamaressa and Karamara, the estimated soil loss was higher owing to the field topographic situations such as high slope gradient. SLEMSA and USLE showed different degrees of sensitivities to their input variables for the conditions of the study sites. SLEMSA was highly sensitive to changes in rainfall kinetic energy (E) and soil erodibility (F) and less sensitive to the cover and slope length factors. The sensitivity of SLEMSA to changes in the cover factor was higher for areas having initially smaller percentage rainfall interception values. On the other hand, USLE was highly sensitive to slope gradient and less so to slope length as compared to the other input factors. The study on the various rates and application patterns of wheat residue on runoff and soil loss both in the laboratory rainfall simulation and under field natural rainfall conditions revealed that surface application of crop residue is more effective in reducing soil loss and runoff than incorporating the same amount of the residue into the soil. Likewise, for a particular residue application method, runoff and soil loss decreased with increasing application rate of the mulch. However, the difference was not significant between 4 Mg ha-1 and 8 Mg ha-1 wheat straw rates suggesting that the former can effectively control soil loss and can be used in areas where there is limitation of crop residues provided that other conditions are similar to that of the study site (AU Regosols). The effectiveness of lower rates of straw (i.e. less than 4 Mg ha-1 ) should also be studied. It should however be noted that the effectiveness of mulching in controlling soils loss and runoff could be different under various slope gradients, rainfall characteristics and cover types that were not covered in this study. Integrated soil and water conservation research is required to develop a comprehensive database for modelling various soil erosion parameters. Further research is therefore required on the effect of soil properties (with special emphasis to aggregate stability, clay mineralogy, exchangeable cations, soil texture and organic matter), types and rates of crop residues, cropping and tillage systems, mechanical and biological soil conservation measures on soil erosion and its conservation for a better estimation of the actual soil loss in the study sites. Copyright 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bobe, BW 2004, Evaluation of soil erosion in the Harerge region of Ethiopia using soil loss models, rainfall simulation and field trials, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-08022004-141533 / >
Thesis (PhD (Soil Science))--University of Pretoria, 2004.
Plant Production and Soil Science
unrestricted
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8

Falkingham, Peter Lewis. "Computer simulation of dinosaur tracks." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/computer-simulation-of-dinosaur-tracks(3b3b150d-c05e-4667-96b5-3c17405856e5).html.

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Fossil tracks represent the only direct record of behaviour and locomotion of extinct animals. A computer model using finite element analysis (FEA) has been developed to simulate vertebrate track formation in cohesive substrates. This model has been designed for, and successfully run on, high performance computing (HPC) resources. A number of individual studies were carried out using the computer model to simulate both abstract indenters and virtual dinosaur autopodia. In addition to the simulation studies, two fossil tracks were described, including the first report of bird tracks at the Mammoth Site of Hot Springs, South Dakota (USA) and a re-description of a 'dinosaur tail drag' as the trace of a crocodilian. Using the computer model, it has been shown that in a wet, soft mud the indentation of a non-webbed virtual tridactyl foot created a resultant track with features analogous to 'webbing' between digits. This 'webbing' was a function of sediment deformation and subsequent failure in 3D, specific to rheology. Apparent webbing impressions were clearly developed only within a limited range of sediment conditions and pedal geometry. Indenter (pedal) geometry and morphology affect track depth independently of substrate and loading parameters. More complex morphologies interact with the cohesive substrate creating a lower effective load than that applied. In non-cohesive substrates such as sand, this effect is reversed, and it is the more compact morphologies that indent to a lesser degree. Virtual sauropod tracks were modelled, based on published soft tissue reconstructions of autopodia anatomy, and published mass/centre of mass estimates. It was shown that foot morphology and differential loading between fore- and hind- limbs leads to a range of substrates in which only the manus or pes are able to generate tracks. This offers a new mechanism for the formation of manus-only sauropod trackways, previously interpreted as having been made by swimming dinosaurs. A series of tracks were simulated using input data (loads, pedal morphologies) from four different dinosaurs (Brachiosaurus, Tyrannosaurus, Struthiomimus, and Edmontosaurus). The cohesive substrates used displayed a 'Goldilocks' effect, allowing the formation for tracks only for a very limited range of loads for any given foot. In addition, there was a strong bias toward larger animals, both in homogeneous and theoretically heterogeneous substrates. These findings imply that interpretations from track assemblages must consider that only a small proportion of the total fauna present may be recorded as a track assemblage due to substrate properties. The use of FEA to simulate dinosaur track formation has been shown to be successful, and offers a number of advantages over physical modelling including; consistency between experiments, specific control over input variables, rapid undertaking of repeatable experiments, and the ability to view subsurface deformation non-destructively. It is hoped that this work will lead to an increased interest in modelling tracks, and offer a quantitative method for studying fossil tracks.
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Rezaur, Rahman Bhuiyan. "Studies on interrill sediment delivery and rainfall kinetic energy." Thesis, Click to view the E-thesis via HKUTO, 1999. http://sunzi.lib.hku.hk/hkuto/record/B42575631.

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Bera, Pubalee. "Computer models for simulating pesticide fate and transport in soil." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=78398.

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Two different modeling approaches to simulate pesticide fate and transport in soil were investigated in this study. First, a process-based mathematical model, DRAINMOD-P, was developed by combining the attractive features of DRAINMOD and PESTFADE. While DRAINMOD formed the main component to perform hydrological predictions, PESTFADE's pesticide sub-model was used to simulate pesticide fate. The new model was validated against three years of independently collected field data from southern Ontario. Several statistical parameters were calculated to evaluate model performance.
Second, an implicit model, Multivariate Adaptive Regression Splines, MARS, which is also a novel data mining tool, was used to assess pesticide transport. MARS was first validated against the field data on three herbicides, namely, atrazine, metribuzin and metolachlor. DRAINMOD-P and MARS simulations, though impressive, need further validations before they can be recommended for actual real-world use.*
*This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Microsoft Office; Adobe Acrobat.
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Книги з теми "Soil erosion Computer simulation"

1

Dräyer, Dietrich. GIS-gestützte Bodenerosionsmodellierung im Nordwestschweizerischen Tafeljura: Erosionsschadenskartierungen und Modellellergebnisse = GIS-based soil erosion modelling in NW-Switzerland : erosion damage mappings and modelling results. Basler: Wepf, 1996.

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2

Bull, Leonard. Soil depletion estimates: Version 2 : a user's guide to a personal computer model for estimating long-term onsite physical and economic impacts of soil depletion. Washington, DC: U.S. Dept. of Agriculture, Economic Research Service, Resources and Technology Division, 1990.

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3

Blaszczynski, Jacek S. Watershed soil erosion, runoff, and sediment yield prediction using geographic information systems: A manual of GIS procedures. Denver, Colo: U.S. Dept. of the Interior, Bureau of Land Management, BLM Service Center, 1994.

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4

Pacific Northwest Research Station (Portland, Or.), ed. Evaluating soil risks associated with severe wildfire and ground-based logging. Portland, OR: U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station, 2011.

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5

Handbook of erosion modelling. Chichester, West Sussex, UK: Wiley, 2011.

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6

Commandeur, P. R. Rainfall simulation, soil infiltration, and surface erosion on skidroad surfaces - Nelson Forest Region. Victoria, B.C: Canadian Forest Service and the British Columbia Ministry of Forests, 1994.

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7

Penning de Vries, F. W. T., Agus F, and Kerr J. M, eds. Soil erosion at multiple scales: Principles and methods for assessing causes and impacts. Oxon: CABI Publishing in association with the International Board for Soil Research and Management, 1998.

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8

Wilson, Joe. Evaluation of the GEOWEB and J.K. STRUCTURE slope stabilization methods. Madison, WI: The Unit, 2000.

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9

Mannaerts, Christiaan. Assessment of the transferability of laboratory rainfall-runoff and rainfall-soil loss relationships to field and catchment scales: A study in the Cape Verde Islands. Enschede: International Institute for Aerospace Survey and Earth Sciences (ITC), 1993.

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Elliot, William J. Water erosion prediction project (WEPP) forest applications. Ogden, UT: U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station, 1997.

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Частини книг з теми "Soil erosion Computer simulation"

1

Dostál, T., J. Váška, and K. Vrána. "SMODERP — A Simulation Model of Overland Flow and Erosion Processes." In Soil Erosion, 135–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04295-3_8.

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Botterweg, Peter. "Snowmelt and Frozen Soils in Simulation Models." In Modelling Soil Erosion by Water, 365–76. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-58913-3_27.

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Molina, J. A. E., M. J. Shaffer, R. H. Dowdy, and J. F. Power. "Simulation of Tillage Residue and Nitrogen Management." In Soil Erosion and Crop Productivity, 413–30. Madison, WI, USA: American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, 2015. http://dx.doi.org/10.2134/1985.soilerosionandcrop.c22.

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4

Zakharov, Y. N., K. S. Ivanov, and I. E. Saltykov. "Finite-Element Method in Tasks of Loose Soil Erosion." In Communications in Computer and Information Science, 228–35. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-12203-4_23.

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5

Roo, A. P. J. "Assessment of Soil Vulnerability to Soil Erosion Using Gis and Simulation Models in Catchments in The Netherlands and The United Kingdom." In Soil & Environment, 337–40. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-2008-1_80.

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Puente, Cesar, Gustavo Olague, Stephen V. Smith, Stephen H. Bullock, Miguel A. González-Botello, and Alejandro Hinojosa-Corona. "A Novel GP Approach to Synthesize Vegetation Indices for Soil Erosion Assessment." In Lecture Notes in Computer Science, 375–84. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01129-0_42.

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Zhang, Guang, Dong Zi Pan, Jing Xi Chen, and Ai Fang Zhou. "Analysis of Pile-Soil Interaction by Computer Simulation." In Experimental Mechanics in Nano and Biotechnology, 1531–34. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-415-4.1531.

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Tian, Yu, Jihui Fan, Feipeng Xiao, and Genwei Cheng. "A New Soil Erosion Model for Hilly Region Based on Information Technology." In Communications in Computer and Information Science, 473–83. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-21411-0_77.

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Xiong, Zhaoyu, Hao Zhang, Haipeng Li, and Dan Xu. "An Optimized Material Point Method for Soil-Water Coupled Simulation." In Advances in Computer Graphics, 569–81. Cham: Springer Nature Switzerland, 2022. http://dx.doi.org/10.1007/978-3-031-23473-6_44.

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Yu, Ming, Yao Huang, Chaofeng Sun, and Yong Wu. "Spatial-Temporal Analysis of Soil Erosion in Ninghua County Based on the RUSLE." In Communications in Computer and Information Science, 553–62. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-3966-9_61.

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Тези доповідей конференцій з теми "Soil erosion Computer simulation"

1

Dong, Jian-peng, and Hui Li. "Freezing and thawing erosion test and particle flow simulation of caragana root-soil complex." In International Conference on Cloud Computing, Internet of Things, and Computer Applications, edited by Warwick Powell and Amr Tolba. SPIE, 2022. http://dx.doi.org/10.1117/12.2642607.

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2

Yong-xia, Wei, Li Na, and Chen Lijun. "Study on the High-Dimension Non-linear Index Model GWS(n,m) for Soil Erosion Simulation and Its Parameters Identification Method." In 2009 WRI World Congress on Computer Science and Information Engineering. IEEE, 2009. http://dx.doi.org/10.1109/csie.2009.151.

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Abodeely, Jared M., David J. Muth, Joshua Koch, and Kenneth M. Bryden. "An Integrated Model Approach for Quantifying Carbon Emissions From Residue-Based Biofuel Production." In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-13491.

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This paper presents an agricultural residue removal decision framework that couples the environmental process models WEPS, RUSLE2, SCI, and DAYCENT. One of the goals of this integrated model is to quantify the impacts of land management strategies on soil organic carbon and CO2 emissions. Soil, climate, and land management practices are considered in determining sustainable residue removal rates using wind- and water-induced soil erosion and qualitative soil organic carbon constraints and to quantify the long-term impacts of sustainable residue removal on soil organic carbon and greenhouse gas emissions. Using this integrated model sustainable residue removal for four crop rotations, three tillage regimes, and four soil types representing nearly 70% of the arable acres in Boone County, Iowa are examined. Each scenario was performed for a twenty-year period. Soil organic carbon and CO2 emission results are aggregated by soil type using crop rotation and tillage statistics. The soil type results are aggregated using a normalized percentage area to provide a county level estimate of soil organic carbon changes and CO2 emissions. Results show that for the largest sustainable residue removal rate that soil organic carbon increased 3.53–6.63 Mg/ha over the 20 year simulation and that CO2 emissions ranged from 3.50–4.23 Mg/ha across the four soil types resulting in an average increase of soil organic carbon of 4.85 Mg/ha and CO2 emission of 3.77 Mg/ha at the county level.
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Gunadi, I. Gede Aris, Dewi Oktofa Rachmawati, Aldi Prayoga, and Muhammad Fauzan. "Simulation-Prediction Model of Soil Erosion in Lake Buyan." In 4th International Conference on Innovative Research Across Disciplines (ICIRAD 2021). Paris, France: Atlantis Press, 2022. http://dx.doi.org/10.2991/assehr.k.211222.014.

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"Sustainable soil and water resources: modelling soil erosion and its impact on the environment." In 19th International Congress on Modelling and Simulation. Modelling and Simulation Society of Australia and New Zealand (MSSANZ), Inc., 2011. http://dx.doi.org/10.36334/modsim.2011.plenary.sander.

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Zhang, Shiyan, Jennifer G. Duan, and Theodor S. Strelkoff. "Simulation of Unsteady Flow and Soil Erosion in Irrigation Furrows." In World Environmental and Water Resources Congress 2010. Reston, VA: American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41114(371)216.

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Jia Xingli, Xu Jinliang, and Yang Hongzhi. "GIS-based soil erosion-prone evaluation of highway domain." In 2011 International Conference on Computer Science and Network Technology (ICCSNT). IEEE, 2011. http://dx.doi.org/10.1109/iccsnt.2011.6182377.

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Qingshun Wei. "Application in soil erosion studying based on CFD numerical simulation method." In 2011 International Conference on Electric Technology and Civil Engineering (ICETCE). IEEE, 2011. http://dx.doi.org/10.1109/icetce.2011.5775712.

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Biswas, Dipankar, Steven A. Lottes, Pradip Majumdar, and Milivoje Kostic. "Development of an Analysis Methodology for Pressure Flow Scour Under Flooded Bridge Decks Using Commercial CFD Software." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37198.

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Bridges are a significant component of the ground transportation infrastructure in the United States. With about sixty percent of bridge failures due to hydraulic causes, primarily scour, application of computational fluid dynamics (CFD) analysis techniques to the assessment of risk of bridge failure under flood conditions can provide increased accuracy in scour risk assessment at a relatively low cost. The analysis can be used to make optimum use of limited federal and state funds available to maintain and replace bridges and ensure public safety while traveling on the nation’s roads and highways during and after floods. Scour is the erosion of riverbed material during high flow conditions, such as floods. When scouring of the supporting soil around the piers and abutments of bridges takes place, risk of bridge failure increases. A simulation methodology to conservatively predict equilibrium shape and size of the scour hole under pressure flow conditions for flooded bridge decks using commercial CFD software was developed. The computational methodology has been developed using C++ to compute changes in the bed contour outside of the CFD software and generate a re-meshing script to change the bed boundary contour. STAR-CD was used to run the hydrodynamic analysis to obtain bed shear stress, and a BASH script was developed to automate cycling between computing bed shear stress with the CFD software and computing changes in the bed contour due to scour predicted using the computed shear stress for the current bed contour. A single-phase moving boundary formulation has been developed to compute the equilibrium scour hole contour that proceeds through a series of quasi-steady CFD computations. It is based on CFD analysis of the flow fields around the flooded bridge deck and shear stress computed at the bed modeled as a rough wall. A high Reynolds number k-ε turbulence model with standard wall functions, based on a Reynolds-Averaged Navier-Stokes (RANS) turbulence model, was used to compute bed shear stress. The scour sites on the bed were identified as those sites where the computed shear stress exceeded the critical shear stress computed from a published correlation for flat bed conditions. Comparison with experimental data obtained from the Turner-Fairbank Highway Research Center (TFHRC), McLean, VA, USA, revealed larger discrepancies than anticipated between the bridge inundation ratio and the scour hole depth. Although scour hole slopes were small for the cases tested, a correction to critical shear stress to account for bed slope was also tested. It did not significantly improve the correlation between CFD prediction and experimental observations. These results may be a consequence of using only excess shear stress above critical as a criteria for scour when other physical mechanisms also contribute to the initiation of scour. Prediction of scour depth using federal guidelines over predicts scour depth by as much as an order of magnitude in some cases. Over prediction is acceptable for purposes of ensuring bridge safety. CFD methods for scour prediction can be a significant improvement of current methods as long as under prediction of scour depth is avoided. Conservative scour prediction using CFD methods can be achieved by using conservative values of parameters such as critical shear stress and effective bed roughness.
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Kamalzare, Mehrad, Tianning Steven Han, Matt McMullan, Chris Stuetzle, Thomas F. Zimmie, Barbara Cutler, and W. Randolph Franklin. "Computer Simulation of Levee Erosion and Overtopping." In Geo-Congress 2013. Reston, VA: American Society of Civil Engineers, 2013. http://dx.doi.org/10.1061/9780784412787.186.

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Звіти організацій з теми "Soil erosion Computer simulation"

1

Shani, Uri, Lynn Dudley, Alon Ben-Gal, Menachem Moshelion, and Yajun Wu. Root Conductance, Root-soil Interface Water Potential, Water and Ion Channel Function, and Tissue Expression Profile as Affected by Environmental Conditions. United States Department of Agriculture, October 2007. http://dx.doi.org/10.32747/2007.7592119.bard.

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Constraints on water resources and the environment necessitate more efficient use of water. The key to efficient management is an understanding of the physical and physiological processes occurring in the soil-root hydraulic continuum.While both soil and plant leaf water potentials are well understood, modeled and measured, the root-soil interface where actual uptake processes occur has not been sufficiently studied. The water potential at the root-soil interface (yᵣₒₒₜ), determined by environmental conditions and by soil and plant hydraulic properties, serves as a boundary value in soil and plant uptake equations. In this work, we propose to 1) refine and implement a method for measuring yᵣₒₒₜ; 2) measure yᵣₒₒₜ, water uptake and root hydraulic conductivity for wild type tomato and Arabidopsis under varied q, K⁺, Na⁺ and Cl⁻ levels in the root zone; 3) verify the role of MIPs and ion channels response to q, K⁺ and Na⁺ levels in Arabidopsis and tomato; 4) study the relationships between yᵣₒₒₜ and root hydraulic conductivity for various crops representing important botanical and agricultural species, under conditions of varying soil types, water contents and salinity; and 5) integrate the above to water uptake term(s) to be implemented in models. We have made significant progress toward establishing the efficacy of the emittensiometer and on the molecular biology studies. We have added an additional method for measuring ψᵣₒₒₜ. High-frequency water application through the water source while the plant emerges and becomes established encourages roots to develop towards and into the water source itself. The yᵣₒₒₜ and yₛₒᵢₗ values reflected wetting and drying processes in the rhizosphere and in the bulk soil. Thus, yᵣₒₒₜ can be manipulated by changing irrigation level and frequency. An important and surprising finding resulting from the current research is the obtained yᵣₒₒₜ value. The yᵣₒₒₜ measured using the three different methods: emittensiometer, micro-tensiometer and MRI imaging in both sunflower, tomato and corn plants fell in the same range and were higher by one to three orders of magnitude from the values of -600 to -15,000 cm suggested in the literature. We have added additional information on the regulation of aquaporins and transporters at the transcript and protein levels, particularly under stress. Our preliminary results show that overexpression of one aquaporin gene in tomato dramatically increases its transpiration level (unpublished results). Based on this information, we started screening mutants for other aquaporin genes. During the feasibility testing year, we identified homozygous mutants for eight aquaporin genes, including six mutants for five of the PIP2 genes. Including the homozygous mutants directly available at the ABRC seed stock center, we now have mutants for 11 of the 19 aquaporin genes of interest. Currently, we are screening mutants for other aquaporin genes and ion transporter genes. Understanding plant water uptake under stress is essential for the further advancement of molecular plant stress tolerance work as well as for efficient use of water in agriculture. Virtually all of Israel’s agriculture and about 40% of US agriculture is made possible by irrigation. Both countries face increasing risk of water shortages as urban requirements grow. Both countries will have to find methods of protecting the soil resource while conserving water resources—goals that appear to be in direct conflict. The climate-plant-soil-water system is nonlinear with many feedback mechanisms. Conceptual plant uptake and growth models and mechanism-based computer-simulation models will be valuable tools in developing irrigation regimes and methods that maximize the efficiency of agricultural water. This proposal will contribute to the development of these models by providing critical information on water extraction by the plant that will result in improved predictions of both water requirements and crop yields. Plant water use and plant response to environmental conditions cannot possibly be understood by using the tools and language of a single scientific discipline. This proposal links the disciplines of soil physics and soil physical chemistry with plant physiology and molecular biology in order to correctly treat and understand the soil-plant interface in terms of integrated comprehension. Results from the project will contribute to a mechanistic understanding of the SPAC and will inspire continued multidisciplinary research.
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Russo, David, and William A. Jury. Characterization of Preferential Flow in Spatially Variable Unsaturated Field Soils. United States Department of Agriculture, October 2001. http://dx.doi.org/10.32747/2001.7580681.bard.

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Preferential flow appears to be the rule rather than the exception in field soils and should be considered in the quantitative description of solute transport in the unsaturated zone of heterogeneous formations on the field scale. This study focused on both experimental monitoring and computer simulations to identify important features of preferential flow in the natural environment. The specific objectives of this research were: (1) To conduct dye tracing and multiple tracer experiments on undisturbed field plots to reveal information about the flow velocity, spatial prevalence, and time evolution of a preferential flow event; (2) To conduct numerical experiments to determine (i) whether preferential flow observations are consistent with the Richards flow equation; and (ii) whether volume averaging over a domain experiencing preferential flow is possible; (3) To develop a stochastic or a transfer function model that incorporates preferential flow. Regarding our field work, we succeeded to develop a new method for detecting flow patterns faithfully representing the movement of water flow paths in structured and non-structured soils. The method which is based on application of ammonium carbonate was tested in a laboratory study. Its use to detect preferential flow was also illustrated in a field experiment. It was shown that ammonium carbonate is a more conservative tracer of the water front than the popular Brilliant Blue. In our detailed field experiments we also succeeded to document the occurrence of preferential flow during soil water redistribution following the cessation of precipitation in several structureless field soils. Symptoms of the unstable flow observed included vertical fingers 20 - 60 cm wide, isolated patches, and highly concentrated areas of the tracers in the transmission zone. Soil moisture and tracer measurements revealed that the redistribution flow became fingered following a reversal of matric potential gradient within the wetted area. Regarding our simulation work, we succeeded to develop, implement and test a finite- difference, numerical scheme for solving the equations governing flow and transport in three-dimensional, heterogeneous, bimodal, flow domains with highly contrasting soil materials. Results of our simulations demonstrated that under steady-state flow conditions, the embedded clay lenses (with very low conductivity) in bimodal formations may induce preferential flow, and, consequently, may enhance considerably both the solute spreading and the skewing of the solute breakthrough curves. On the other hand, under transient flow conditions associated with substantial redistribution periods with diminishing water saturation, the effect of the embedded clay lenses on the flow and the transport might diminish substantially. Regarding our stochastic modeling effort, we succeeded to develop a theoretical framework for flow and transport in bimodal, heterogeneous, unsaturated formations, based on a stochastic continuum presentation of the flow and a general Lagrangian description of the transport. Results of our analysis show that, generally, a bimodal distribution of the formation properties, characterized by a relatively complex spatial correlation structure, contributes to the variability in water velocity and, consequently, may considerably enhance solute spreading. This applies especially in formations in which: (i) the correlation length scales and the variances of the soil properties associated with the embedded soil are much larger than those of the background soil; (ii) the contrast between mean properties of the two subdomains is large; (iii) mean water saturation is relatively small; and (iv) the volume fraction of the flow domain occupied by the embedded soil is relatively large.
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