Dissertations / Theses on the topic 'Soil infiltration'
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1
Barrett, Gary Edward. "Infiltration in water repellent soil." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28618.
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Observations made at Goat Meadows - a small sub-alpine basin located near Pemberton, British Columbia -demonstrated that a layer which is either water repellent or has only a limited affinity for water is present at most vegetated sites. The layer is typically a few centimetres in thickness, and is usually located at or near the top of the profile: it was present only in the zone of accumulation of organic matter. The spatial distribution of the layer did not appear to be related to the distribution of any particular species of plant. Sampling of sub-alpine sites in the Cascade, Selkirk, and Purcell Mountains indicated that such layers are common in the alpine - sub-alpine ecotone of southern British Columbia.
The relationship between ponding depth and infiltration rate was explored through experiments conducted on samples collected near Ash Lake, in Goat Meadows. These samples were chosen for analysis because the repellent layer was in excess of thirty centimetres thick at this site. Infiltration rates remained below 2x10⁻⁹ m/s for all samples, even given ponding depths of up to forty centimetres. Breakthrough of liquid water was not observed, even after one month, which implies that most of the infiltration occurred as vapour transfer.
In order to observe the movement of liquid water through water repellent media, a plexiglas cell was constructed. A synthetic water repellent sand with uniform surface properties was used as the medium. It was found that up to some critical depth, there was no entry of water into the medium. As the ponding depth was increased in steps, the front would advance in steps: it remained stationary between these step-increases in ponding depth. As the front advanced, protuberances or "fingers" began to develop. At some critical ponding depth, a finger would grow without bound. These observations pose a challenge to existing models of infiltration, since it appears that heterogeneity at the scale of individual pores must be invoked to explain them, but it is usually assumed that the properties of a porous medium are continuous at this scale.
The thermodynamics of filling and emptying of pores is considered with emphasis on the effects of pore shape and of variations in the physicochemical properties at the scale of the pore. This thermodynamic analysis provides the conceptual basis for development of a model of infiltration in which pore-scale heterogeneity is preserved. Although it was not developed as such, the model follows the approach of cellular automata, in which local relations between pores or "cells" govern the behaviour of the system. The model replicated the observations of infiltration into synthetic water repellent porous media well: both the halting advance of the front as the ponding depth was increased and the development of fingers were simulated. The fact that such complex behaviour was predicted using only a simple set of physically based rules confirms the power of the approach.Arts, Faculty of
Geography, Department of
Graduate
2
Ng, Man-chung, and 吳敏聰. "Water infiltration in unsaturated soil slope." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B46599642.
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Kwong, Chin Pang. "Field and laboratory experimental study of water infiltration in cracked soil /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202009%20KWONG.
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Nyawakira, Bernard 1955. "Evaluation of two furrow infiltration measuring methods and furrow spacings." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277171.
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The effect of furrow spacing on infiltration should be determined in order to properly design an irrigation system. The blocked furrow infiltrometer (BFI) and the flowing furrow infiltrometer (FFI) methods were investigated for this purpose in two areas upon a precision field furrow. Three irrigations were performed in each method. The initial and final soil moisture contents (before and after irrigation), the furrow cross-section (before and after irrigation), the inflow volume and the furrow water surface elevations (during irrigation) were measured in each test furrow. Cumulative infiltration and infiltration rates were determined for each irrigation. The results indicate that the FFI test furrows infiltrated more water than did the BFI test furrows for the same infiltration time. The infiltration rates were higher in the FFI test furrows than in the BFI test furrows until they approach the basic intake rate. The infiltration rates were also higher during the 0.90 m spacing tests than during the 1.80 m spacing tests. The 0.90 m spacing test furrows infiltrated more water than did the 1.80 m spacing test furrows.
5
Nilsson, Peter. "Infiltration of wastewater : an applied study on treatment of wastewater by soil infiltration /." Lund, Sweden : Dept. of Environmental Engineering, Lund Institute of Technology, University of Lund, 1990. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=006106905&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Pimental-Lopez, Jose. "Modeling two-dimensional infiltration from furrows." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/279977.
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Numerical simulations were performed to study two-dimensional infiltration from furrows. The simulations were carried out using the models SWMS_2D, HYDRUS-2D and HYDRUS-1D. The first model was used to evaluate the individual effect of soil and furrow parameters on cumulative infiltration and deep seepage. Cumulative infiltration was found to be more sensitive to saturated hydraulic conductivity, wetted perimeter and furrow spacing than the other parameters for relatively long times, while cumulative deep seepage was more sensitive to the same parameters except to the furrow spacing. It was verified that two-dimensional cumulative infiltration can be approximated using one-dimensional models, for example HYDRUS-1D, by combining the vertical and horizontal infiltrations. The two-dimensional cumulative infiltration is underpredicted by no more than 35% using this calculation. When steady state is reached the steady infiltration rate may be linearly related to the depth of the furrow. As a result, steady infiltration rate is dependent only on type of soil, water depth in the furrow and furrow width. Broocks-Corey soil hydraulic parameters were matched to the van Genuchten parameters by four different procedures. The method based on matching sorptivities produced the closest results to the van Genuchten solution for one- and two-dimensional cumulative infiltration. However, cumulative deep seepage was not accurately simulated. The SCS infiltration parameters were also matched but using an inverse problem methodology. The parameters obtained described cumulative infiltration reasonably well.
7
Li, Jinhui. "Field experimental study and numerical simulation of seepage in saturated/unsaturated cracked soil /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202009%20LIJ.
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8
Killen, Mark Albert. "A physically based analytical model to predict infiltration under surge irrigation." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184379.
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A significant advantage attributed to surge flow irrigation is that for the same volume of water applied the stream will advance farther along the furrow than with continuous flow. This potentially will reduce runoff and deep percolation which will improve uniformity and application efficiency where this advance phenomenon holds. The mechanism for improvement in advance time has generally been ascribed to surface sealing and surface layer consolidation. However, these phenomena do not satisfactorily explain improved advance times in sandy soils. Widely used infiltration equations which require the determination of empirical coefficients are unsatisfactory as predictors of infiltration conditions of intermittent wetting. The Green-Ampt model and a simple redistribution model are combined into an analytical model to predict infiltration under surge irrigation. The model results are compared to infiltration tests on soil columns of three soils of different soil textures. Also the model and the experimental results from the soil columns are compared to predictions made by two numerical solutions of the Richard's equation. One of the numerical models includes the effect of hysteresis by the use of Mualem's model to predict the variation of moisture content with potential, the other numerical model neglects the effect of hysteresis. A comparison of the analytical and the numerical models shows good agreement in their predictions for the soils and surge cycles tested. A comparison of predictions made by all three models shows good correlation to the experimental results. Although the number of tests done on the analytical model were limited it appears to be nearly as good a predictor of infiltration as the numerical models. The greatest strength of the analytical model is that while the numerical models took many hours to do a single run, the analytical model took only a few minutes. Both model and experimental results indicate that there was no reduction in infiltration rates or volumes infiltrated with intermittent as compared to continuous wetting. Thus the reduction in hydraulic gradient is not a factor in the reduced infiltration observed by others.
9
Smith, Philip Graham Clark. "Numerical analysis of infiltration into partially saturated soil slopes." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407342.
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K, C. Milan. "Applicability of Soil Moisture Sensors in Determination of Infiltration Rate." University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1509217475534338.
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11
GARCIA, ARISTIZABAL Edwin Fabian. "Numerical Analysis of the Rainfall Infiltration Problem in Unsaturated Soil." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/126786.
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CONCIALDI, Paola. "INVESTIGATIONS ON INFILTRATION METHODS FOR AN IMPROVED SOIL HYDRAULIC CHARACTERIZATION." Doctoral thesis, Università degli Studi di Palermo, 2020. http://hdl.handle.net/10447/440688.
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Harper, John, Jack Watson, and Tom Doerge. "The Effect of Various Soil Amendments on the Yield of Alfalfa and Soil Infiltration Rates." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200479.
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El-Kafri, Manal M. Lutfi. "Symmetry methods applied to Richard's equations and problems of infiltration." Thesis, University of South Wales, 2006. https://pure.southwales.ac.uk/en/studentthesis/symmetry-methods-applied-to-richards-equations-and-problems-of-infiltration(e94a3a66-f16b-46cd-a9c8-192ac6b995bc).html.
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Water resources development around the world has taken many different forms and directions since the dawn of civilization. Water shortage in arid and semiarid regions has encouraged the search for additional sources currently not exploited intensively. Hence, knowledge of the infiltration process is a requirement for understanding water management. The main aim here is to solve the one-dimensional nonlinear time-dependent Richard's equation for water flow in an unsaturated uniform soil. The main theory of soil infiltration is introduced using a mathematical-physical approach to describe water movement in unsaturated soils. This gives rise to Richard's flow equation; which is presented for both unsaturated and also saturated soil. Methods for solving Richard's equation by both analytical and numerical techniques are then introduced. This gives rise to a discussion of the similarity methods first used by Philip to determine analytical solutions of Richard's equation in an unsaturated soil. This is then generalised to determine a broader class of solutions using the Lie (classical) symmetry approach. The non-classical symmetries of Bluman and Cole are also determined. Although these group methods provide the most widely applicable technique to find solutions of ordinary and partial differential equations, a large number of tedious calculations are involved. With the help of computer algebra it is shown that the determining equations for the non-classical case lead to four new highly non-linear equations which are solved in five particular cases. Each case of classical and non-classical solutions is then reduced to an ordinary differential equation and explicit solutions are produced when possible. The potential classical and non-classical method, first suggested by Bluman, Reid and Kumei, is also discussed and presented. The potential non-classical method produced new results, which the potential classical method did not. The solution is useful as a tool by which to judge the quality of numerical methods. A practical solution of classical (Lie/ potential) and non-classical symmetry of Richard's equation is presented. Finally, conclusions and suggestions for further work are discussed.
15
Schaffer, Joseph F. "Verification and Adaptation of an Infiltration Model for Water at Various Isothermal Temperature Conditions." Digital WPI, 1999. https://digitalcommons.wpi.edu/etd-theses/1061.
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"A series of one dimensional horizontal infiltration experiments were performed to investigate the predictive capabilities of the Kao and Hunt model. By modifying pristine laboratory apparatus, a reasonable range of soil temperatures was achieved. Experiments were run at approximately 5°C, 20°C, and 35°C. Distilled water was used as an infiltrating liquid and silica powder was used as soil. The infiltrating liquid was dispensed into the column at zero pressure head. The results of the experiments show that the model is adaptable to a range of temperature conditions by modifying terms for the liquid effects of the model, viscosity and surface tension. Experimental data and model predictions differed by 30 percent at most. Although the change in the rate of infiltration across the range of temperatures is perceivable, it is small in comparison to the effects caused by heterogeneity encountered in nature. "
16
Bagour, Mohammed Hussien. "Measuring and predicting steady state infiltration rates for Arizona irrigated soils." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279790.
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Five methods to measure the saturated hydraulic conductivity of Arizona irrigated soils were evaluated using the in-situ single ring, double ring, compact constant head permeameter methods, and with tempe cells (soil cores) in the laboratory. Ten Arizona irrigated soils were studied, and the textures of these soils ranged from sand to silty clay. Three water qualities were evaluated, namely the local water, gypsum in local water, and gypsum water (0.005M CaSO₄ · 2H₂O solution). Sites were selected to provide soils having a wide range of soil characteristics and detailed laboratory and field morphology data were measured including soil texture, bulk density, soil aggregation, stickiness, plasticity, moisture retention at various tensions, ECₑ, and pHₑ. The results showed that the double ring method was the better in-situ method. The relationships between soil properties and K(sat) were evaluated, and soil properties were examined as predictor variables for K(sat) in stepwise multiple-regression. Stepwise multiple-regression criteria were set at a probability of F to enter ≤ 0.5 and probability of F to remove ≥ 0.1. Six models are presented that can be used in predicting K(sat). Each model has a subset of field and laboratory predictor variables selected based on stepwise multiple-regression criteria, and with some personal judgment. Casewise diagnostics were used to test model performances.
17
DeBusk, Kathy Marie. "Stormwater Treatment by Two Retrofit Infiltration Practices." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/32757.
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Increases in impervious surfaces associated with urbanization change stream
hydrology by increasing peak flow rates, storm-flow volumes and flood frequency, and
degrade water quality through increases in sediment, nutrient, and bacteria
concentrations. In response to water quality and quantity issues within the Stroubles
Creek watershed, the Town of Blacksburg and Virginia Tech designed and constructed
two innovative stormwater best management practices (BMPs). The goal of this project
was to evaluate the effectiveness of a bioretention cell and a CU-Structural Soilâ ¢
infiltration trench. BMP construction was completed in July 2007. Twenty-nine
precipitation events were monitored over a period of five months between October 2007
and March 2008. For each storm, inflow and outflow composite samples were collected
for each BMP and analyzed for suspended sediment, total nitrogen, total phosphorus,
fecal coliform bacteria and E-coli bacteria. The inflow and outflow concentrations and
loads, as well as total inflow and outflow volumes and peak flow rates, were then
compared to evaluate how well each BMP reduces stormwater flows, decrease peak
runoff rates and improves water quality of stormwater runoff. Results for the bioretention
cell indicate average reductions in stormwater quantity, sediment, total nitrogen, total
phosphorus and fecal coliform bacteria that exceeded 99% by mass. The CU-Structural
Soilâ ¢ infiltration trench produced reductions in stormwater quantity, total phosphorus
and sediment that averaged 60%, 45% and 51%, respectively. Preliminary bacteria
results indicated that both BMPs served as sources of E-coli, and the infiltration trench
served as a source of fecal coliform bacteria.Master of Science
18
Sande, Leif Andrew. "Experimental Studies on Infiltration/Soil-Water Movement Processes and Green-AMPT Modeling." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29329.
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Experimental studies on infiltration/soil-water movement processes are vital to
better understanding movement of soil-water in the vadose zone. The objective of this
experimental research was to investigate infiltration/soil-water movement processes
utilizing laboratory experiments and computer modeling. Small scale laboratory soil box
infiltration experiments were conducted and utilized for the improved parameterization of
the Green-Ampt (GA) saturated moisture content parameter to produce an effective
moisture content parameter (Be) for utilization in a modified GA model. By incorporating ?e
values into GA modeling, modeling results showed greatly improved wetting front
prediction across different soil conditions. A new soil packing method was proposed for
replicating complex microtopographical surfaces with uniform bulk densities in laboratory
soil box experiments which proved efficient and effective at accomplishing both objectives.
A rainfall simulator and an instantaneous-profile laser scanner were used to simulate
rainfall and quantify surface microtopography for experiments. The results clearly show the
effect of microtopography on infiltration and soil-water movement characteristics. This
offers valuable insight into infiltration/soil-water movement processes as affected by
different soil and surface microtopographic conditions.National Science Foundation (Grant No. EAR-0907588)
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Hathaway-Jenkins, Laura Jane. "The effect of organic farming on soil physical properties, infiltration and workability." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/6798.
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Organically managed land has increased to 4 % of the total area of agricultural land in the UK. Changing land management can impact upon the rural environment (soils, hydrology and biodiversity) and rural community (socio-economics and culture). This thesis aims to compare the effects of organic farming practices on soil physical, chemical and hydrological properties in relation to conventional farming systems. The research combines data from three different scales: field measurements, plot measurements and catchment modelling. At the field scale: 16 pairs of farms (organic and conventional between 50 and 3000 m apart) located in England, over a range of soil textures: clayey, silty, medium and coarse were investigated. There were also two different land uses (grass and winter wheat). Data was obtained on soil properties including: shear strength, Atterberg limits, field capacity, aggregate stability, HOST values, infiltration rates and Soil Organic Carbon (SOC). The analysis of the data shows that, whilst it is possible to detect the effects of both soil texture and land use (grassland / arable) on a number of the soil properties; there is no evidence that organic farming improves soil properties or physical condition - equally there is no detrimental effect. This is in agreement with the results of a number of other European studies. There was evidence to show that infiltration rates are greater on organically managed grassland than conventional grassland; which agrees with the HOST analysis where fewer fields were degraded under organic management. Fewer traces of pesticides and herbicides were in the soil water from the organic fields compared with the conventionally managed fields; none were at a level which would contribute to agricultural pollution. Cont/D.
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Freitas, Robert Joseph 1953. "Estimating infiltration parameters from remotely sensed vegetative cover and measured soil properties." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/192058.
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Vegetation cover and soils data were taken on sites in Arizona, Oklahoma and South Dakota and analyzed using remotely sensed high resolution panchromatic photographs and standard field sampling techniques. Results showed that photographs of WEPP rainfall simulator plots can be used to determine vegetative cover. Photographs were converted to digital format and image processed. These measurements, in conjunction with soils sampled in open areas and under canopies, provided improved estimates of saturated hydraulic conductivity. Infiltration rates predicted from parameters estimated by soil hydraulic measurements and the areal extent of vegetative cover were then compared with observed infiltration rates taken directly from rainfall simulated erosion plots. It is concluded that infiltration parameters for shrub dominated rangelands can be more accurately estimated by incorporating remotely sensed vegetative cover estimates and characteristics of soil properties under cover.
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Khatibi, Asfanjani Danial. "Determination of Homogeneity and Isotropy of Soil Using Geophysical Methods." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171849.
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Cognition of the hydraulic properties of soils is important in civil and environmental projects such as for water supply, geotechnical investigations and evaluation of pollutant spreading. This pilot project aims to develop and test a new method for characterization of the homogeneity and isotropy of different soils by using geophysical measurements. The method is based on geoelectrical (resistivity) measurements using a radial array. Using a radial array with electrode lines in various orientations crossing a midpoint at which water was infiltrated, it was possible to build a 3D-block model showing the water penetration into a soil body. Based on the infiltration pattern it was possible to evaluate the hydraulic heterogeneity and anisotropy of the material. Several common Swedish types of soils were tested. Measurement and evaluation techniques including software were developed. The project shows that geoelectrical measurements using a radial array and geoelectrical instruments available on the market can be used for rapid evaluation of the hydraulic heterogeneity and anisotropy of soils and rock.
22
Glatz, Thomas. "The electro-osmotic acceleration of infiltration into the subgrade of pavements." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16326.
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Thesis (MScIng)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: The moisture content of road foundations plays an important role in the durability of the pavement and the driving comfort of the road. After a pavement has been completed, gradual moisture changes occur in the foundations until equilibrium conditions can be reached, and this can have negative results if expansive clays, for example, are present in the foundation. Pre-wetting of the foundation material is seen as a method to minimilize moisture changes after construction, but if the pavement was already completed, it would be very difficult to change or alter the moisture content in the foundation, because water could then only be applied to the shoulder areas of the road and horizontal infiltration in the soil is exceptionally slow. The research which is reported in this account was undertaken to determine whether the process of electro-osmosis could be applied to accelerate water infiltration underneath covered areas, as in, for example, road foundation layers. Electro-osmosis, if found to be successful, has various advantages, of which the most important is that it can be applied without stopping the normal operations of the road. This research was carried out on a mixture of G5 material (TRH14 classification) and fine material in the form of clay with a low plasticity. Firstly, tests were performed to determine the percentage of fines required. It was found that, if too little fines were present infiltration did not occur, because moisture could flow freely through the openings between the rough aggregate. Electro-osmosis also had no effect on the rate of flow. The allocated amount of fines required to fill sufficient openings was about 30% (TRH14 classification of mixture is G10). Free flow was stopped and true infiltration occurred. Simultaneously, the rate of infiltration could be accelerated with electro-osmosis. Furthermore, a two-dimensional model of a road was constructed with electrodes placed on both sides, with the aim to determine the infiltration pattern controlled by electro-osmosis and what the effect of the initial moisture content would be on the process. Water was introduced to the one side of the model road and the wetting of the foundation was investigated. If the electric current for electro-osmosis was switched off, the infiltration was mainly vertical, as expected, but with the current switched on, there was an obvious acceleration of infiltration in the horizontal direction. As in the case of the initial tests, it was found that electro-osmosis was not very successful to accelerate horizontal infiltration at low percentages of fines. Furthermore, it was obvious that electroosmosis was also more effective if the initial moisture content of the soil was low. Low amounts of fines and high initial moisture contents had rather the electroosmotic flow of water passing underneath the road as a result instead of infiltration acceleration, with the result that the moisture content did not change much. The research thus showed that electro-osmosis is a possible manner in which moisture could be conducted into the foundation layers of roads to increase the moisture content if the appropriate amount of fines and moisture content were present in the foundation material. Further research could still be carried out and the materials in each case should be practically evaluated before this method could be continued with.
AFRIKAANSE OPSOMMING: Die voginhoud van padfondamente speel ’n belangrike rol in die duursaamheid van die plaveisel en die rygerief van die pad. Nadat ’n plaveisel voltooi is, vind daar geleidelike vogverandering in die fondamente plaas totdat ewewigstoestande bereik is, en dit kan nadelige gevolge inhou indien uitsettende kleie byvoorbeeld in die fundament teenwoordig is. Voorafbenatting van die fondamentmateriaal word gereken as ’n metode om vogveranderinge na konstruksie te minimeer, maar indien die plaveisel reeds voltooi is, is dit baie moeilik om die voginhoud in die fondament te verander of beheer omdat water dan slegs buite die skouerareas van die pad toegedien kan word en horisontale infiltrasie in grond uiters stadig is. Die navorsing waaroor hierin verslag gedoen word, is onderneem om te bepaal of die proses van elektro-osmose aangewend kan word om waterinfiltrasie onder bedekte areas, soos byvoorbeeld padfondamentlae, te versnel. Elektro-osmose, indien dit suksesvol blyk te wees, hou verskeie voordele in, waarvan die belangrikste dat dit aangewend kan word sonder om die normale bedryf van die pad te staak. Die ondersoek is uitgevoer op ’n mengsel van G5 materiaal (TRH14 klassifikasie) en fynstof in die vorm van klei met ’n lae plastisiteit. Eerstens is toetse uitgevoer om die persentasie fynstof wat nodig is, te bepaal. Daar is bevind dat, indien te min fynstof teenwoordig is, infiltrasie nie plaasvind nie aangesien water vryelik deur die openinge tussen die growwe aggregaat kan vloei. Elektro-osmose het ook geen effek op die vloeitempo gehad nie. Die aangewese hoeveelheid fynstof om genoegsame openinge te vul was ongeveer 30% (TRH14 klassifikasie van mengsel is G10). Vrye vloei is dan gestuit en ware infiltrasie het plaasgevind. Terselfdertyd kon die tempo van infiltrasie versnel word met elektro-osmose. Voorts is ’n twee-dimensionele model van ’n pad gebou, met elektrodes aan weerskante geplaas, met die doel om te bepaal of die infiltrasiepatroon deur elektro-osmose beheer kon word en wat die effek van beginvoginhoud op die proses sal wees. Water is aan een kant van die modelpad ingevoer en die benatting van die fondament bestudeer. Indien die elektriese stroom vir elektroosmose afgeskakel was, was die infiltrasie hoofsaaklik vertikaal, soos verwag, maar met die stroom aangeskakel was daar duidelike versnelling van infiltrasie in die horisontale rigting. Net soos in die geval van die aanvanklike toetse is bevind dat elektro-osmose nie baie suksesvol was om horisontale infiltrasie te versnel by lae persentasies fynstof nie. Dit het verder geblyk dat elektro-osmose ook meer effektief was indien die aanvanklike voginhoud van die grond laag was. Lae hoeveelhede fynstof en hoë aanvanklike voginhoude het eerder elektroosmotiese deurvloei van water onderdeur die pad tot gevolg gehad as infiltrasieversnelling, met die gevolg dat die voginhoud nie veel verander het nie. Die navorsing het dus getoon dat elektro-osmose ’n moontlike wyse is waarop water in die fondamentlae van paaie ingevoer kan word om die voginhoud te verhoog indien die geskikte hoeveelheid fynstof en voginhoud in die fondamentmateriaal teenwoordig is. Verdere navorsing kan nog uitgevoer word en die materiale van elke geval sal prakties evalueer moet word voordat met die metode voortgegaan kan word.
23
Shevelan, John. "Investigating the effects of heterogeneities on infiltration into unsaturated compacted soils." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369917.
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Meng, Huan. "Multifractal analysis of the effects of rainfall and Ks on surface infiltration and runoff." Access citation, abstract and download form; downloadable file 11.10 Mb, 2004. http://wwwlib.umi.com/dissertations/fullcit/3131689.
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Viljoen, Daniel Willem. "Evaluation of the effect of an orange oil based soil Ameliorant on selected soil physical properties." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79826.
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Thesis (MScAgric)--Stellenbosch University, 2013.ENGLISH ABSTRACT: A new orange oil based soil ameliorant is available on the market. Apart from the orange oil, the other main constituents of the product are a nonionic surfactant and an anionic surfactant. Surfactants are used in the agricultural sector, amongst others, as a countermeasure for soil with poor infiltrability or with hydrophobic characteristics. Farmers who applied the orange oil based soil ameliorant to the soil observed a positive growth response by the crop. However, the main concern about surfactants is that it can cause the soil to disperse and thereby decrease the infiltration and saturated hydraulic conductivity thereof. The aim of this study was therefore to determine the effect which this product might have on the following selected soil physical properties: bulk density, aggregate stability, soil strength and unsaturated hydraulic conductivity. The product was applied on four farms on soils with different textures: Dublin Farm (22% clay), Wansbek (20% clay), Toitskraal (7% clay) and Two Rivers (3% clay). Field studies were repeated at Dublin Farm and Toitskraal to study the longevity effect of the product. Differences in bulk density were not attributed to the effect of the product, but to spatial variation. The aggregate stability at the 50 mm depth tended to decrease after application of the product at Dublin Farm trial 1, Toitskraal trial 1 and at Wansbek. At Dublin Farm trial 2 and Toitskraal trial 2 the application of the product tended to increase the aggregate stability. For Dublin Farm trial 2 and Wansbek the shear strength at the 50 mm depth tended to increase with increased application rates. The opposite was observed at Toitskraal and Two Rivers. The unsaturated hydraulic conductivity tended to be higher at the 0 mm depth for the treated soils at all of the trials except Toitskraal trial 2. From the aggregate stability results it is clear that the initial effect of the product was detrimental which can be attributed to the anionic surfactant. The long term effect can be attributed to the effect of the nonionic surfactant. The differences in shear strength can be attributed to aggregate stability (for Dublin Farm trial 2) and bulk density (for Two Rivers). There is however no explanation for the results found at Toitskraal and Wansbek. From the linear regression of bulk density against unsaturated hydraulic conductivity for Wansbek and Two Rivers it is clear that the application of the product definitely had an influence on the unsaturated hydraulic conductivity. For both farms, the correlation between bulk density and unsaturated hydraulic conductivity was better for the control than for the treated soils. To conclude with, the application of the product according to the recommended application rate, resulted in a slightly detrimental effect to the soil on the short term, but on the long term it tended to have a slightly positive effect on the soils.
AFRIKAANSE OPSOMMING: ‘n Nuwe grondverbeteringsproduk met lemoenolie as ‘n basis en ‘n nie-ioniese en ‘n anioniese benattingsmiddel as hoof bestandele, is op die mark. In die landbou sektor word benattingsmiddels onder andere gebruik as ‘n teenvoeter vir gronde met swak infiltrasie of hidrofobiese eienskappe. Die grootste voorbehoud omtrent die gebruik van benattingsmiddels is die moontlike afname in infiltrasie en versadigde hidroulieses geleivermoë as gevolg van klei dispergering. Positiewe reaksies van die gewasse is waargeneem deur boere wat van die produk gebruik maak. Die doel van die studie was dus om die moontlike effek van die bogenoemde grondverbeterings produk op die volgende geselekteerde grondfisiese eienskappe te bepaal: bulkdigtheid, aggregaatstabiliteit, grondsterkte en onversadigde hidrouliese geleivermoë. Die produk is toegedien op vier plase met verskillende grondteksture: Dublin Farm (22% klei), Toitskraal (7% klei), Wansbek (20% klei) and Two Rivers (3% klei). ‘n Ondersoek na die lewensduur van die produk is gedoen deur ‘n opvolg studie te doen by Dublin Farm en Toitskraal. Vir die bulkdigtheid resultate kon geen van die verskille toegeskryf word aan die effek van die produk nie. Die aggregaate stabiliteit by die 50 mm diepte van Dublin Farm proef 1, Toitskraal proef 1 en Wansbek, het geneig om laer te wees vir die behandelde gronde. Die aggregaatstabiliteit by die 50 mm diepte van Dublin Farm proef 2 en Toitskraal proef 2 het geneig om hoër te wees vir die behandelde gronde. Die skuifsterkte by die 50 mm diepte by Dublin Farm proef 2 en Wansbek, het geneig om toe te neem met ‘n toename in toedienings hoeveelheid, terwyl die teenoorgestelde tendens by Toitskraal en Two Rivers waargeneem is waar minder klei teenwoordig is in die grond. Die onversadigde hidroliese geleivermoë het geneig om hoër te wees by die 0 mm diepte van al die plase met die uitsondering van Toitskraal proef 2. Dit is duidelik vanaf die aggregaatstabiliteit resultate dat die aanvanklike effek van die produk nadelig is en dit kan toegeskryf word aan die effek van die anioniese benattingsmiddel. Die langtermyn effek kan toegeskryf word aan die nie-ioniese benatingsmiddel wat aggregaatstabiliteit kan verbeter. Die verskille in skuifsterkte kan toegeskryf word aan die verskille in aggregaatstabiliteit (vir Dublin Farm proef 2) en bulkdigtheid (vir Two Rivers). Daar is egter geen verklaring vir die verskille in skuifsterkte by Toitskraal en Wansbek nie. Die liniêre regressie van bulkdigtheid teenoor onversadigde hidroliese geleivermoë van Wansbek en Two Rivers dui aan dat die produk ‘n invloed het op die onversadigde hidroliese geleivermoë. Vir albei plase het die kontrole die beste liniêre verband tussen die twee grondeienskappe gehad, met ‘n swakker korrelasie vir gronde waar die lemoenolieproduk toegedien is. Dus kan die afleiding gemaak word dat op die korttermyn het die produk ‘n geringe negatiewe effek op die grond, maar op die langtermyn neig dit om ‘n positiewe effek te hê.
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Carrick, Sam. "The dynamic interplay of mechanisms governing infiltration into structured and layered soil columns." Lincoln University, 2009. http://hdl.handle.net/10182/1328.
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Worldwide there is considerable concern over the effects of human activities on the quantity and quality of freshwater. Measurement of infiltration behaviour will be important for improving freshwater management. This study identifies that New Zealand has a sporadic history of measuring soil water movement attributes on a limited number of soil types, although the current practical demand should be large for management of irrigation, dairy farm effluent disposal, as well as municipal / domestic waste- and storm-water disposal. Previous research has demonstrated that infiltration behaviour is governed by the interplay between numerous mechanisms including hydrophobicity and preferential flow, the latter being an important mechanism of contaminant leaching for many NZ soils. Future characterisation will need to recognise the dynamic nature of these interactions, and be able to reliably characterise the key infiltration mechanisms. Since macropores are responsible for preferential flow, it is critical that infiltration studies use a representative sample of the macropore network. The aim of this project was to study the mechanisms governing the infiltration behaviour of a layered soil in large (50 x 70 cm) monolith lysimeters, where the connectivity of the macropore network remains undisturbed. Four lysimeters of the Gorge silt loam were collected, a structured soil with four distinct layers. On each lysimeter there were four separate infiltration experiments, with water applied under suctions of 0, 0.5, 1, and 1.5 kPa by a custom-built tension infiltrometer. Each lysimeter was instrumented with 30 tensiometers, located in arrays at the layer boundaries. There was also a field experiment using ponded dye infiltration to visually define preferential flowpaths. Analysis of dye patterns, temporal variability in soil matric potential (Ψm), and solute breakthrough curves all show that preferential flow is an important infiltration mechanism. Preferential flowpaths were activated when Ψm was above -1.5 kPa. During saturated infiltration, at least 97% of drainage was through the ‘mobile’ pore volume of the lysimeter (θm), estimated among the lysimeters at 5.4 – 8.7 % of the lysimeter volume. Early-time infiltration behaviour did not show the classical square-root of time behaviour, indicating sorptivity was not the governing mechanism. This was consistent across the four lysimeters, and during infiltration under different surface imposed suctions. The most likely mechanism restricting sorptivity is weak hydrophobicity, which appears to restrict infiltration for the first 5 – 10 mm of infiltration. Overall, the Gorge soil’s early-time infiltration behaviour is governed by the dynamic interaction between sorptivity, hydrophobicity, the network of air-filled pores, preferential flow and air encapsulation. Long-time infiltration behaviour was intimately linked to the temporal dynamics of Ψm, which was in turn controlled by preferential flow and soil layer interactions. Preferential flowpaths created strong inter-layer connectivity by allowing an irregular wetting front to reach lower layers within 2 – 15 mm of infiltration. Thereafter, layer interactions dominate infiltration for long-time periods, as Ψm in soil layers with different K(Ψm) relationships self-adjusts to try to maintain a constant Darcy velocity. An important finding was that Ψm rarely attained the value set by the tension infiltrometer during unsaturated infiltration. The results show that ‘true’ steady-state infiltration is unlikely to occur in layered soils. A quasi-steady state was identified once the whole column had fully wet and layer interactions had settled to where Ψm changes occurred in unison through each soil layer. Quasi-steady state was difficult to identify from just the cumulative infiltration curve, but more robustly identified as when infiltration matched drainage, and Ψm measurements showed each layer had a stable hydraulic gradient. I conclude that the in-situ hydraulic conductivity, K(Ψm), of individual soil layers can be accurately and meaningfully determined from lysimeter-scale infiltration experiments. My results show that K(Ψm) is different for each soil layer, and that differences are consistent among the four lysimeters. Under saturated flow the subsoil had the lowest conductivity, and was the restricting layer. Most interestingly this pattern reversed during unsaturated flow. As Ψm decreased below -0.5 to -1 kPa, the subsoil was markedly more conductive, and the topsoil layers became the restricting layers. All four soil layers demonstrate a sharp decline in K(Ψm) as Ψm decreases, with a break in slope at ~ -1 kPa indicating the dual-permeability nature of all layers.
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Roy, James W. "Infiltration, nitrate and chloride leaching, and dicamba fate in unsaturated soil below turfgrass." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35929.pdf.
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Roy, Debjit. "Snowmelt Water Infiltration into Frozen Soil in Red River of the North Basin." Diss., North Dakota State University, 2018. https://hdl.handle.net/10365/27851.
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Infiltration into frozen soils is an important process in the hydrological cycle. Though infiltration occurs at the soil surface, it is affected by many factors, e.g. soil water content, temperature, and hydraulic conductivity. Understanding the snowmelt water infiltration processes into frozen soil helps to address issues about runoff generation and spring flooding in seasonally frozen area like Red River of the North basin (RRB). In this study, the methods of soil water release curve (SWRC) development, the effect of soil water content on frozen soil infiltration, and the variation of hydraulic conductivity for different RRB soils in frozen and unfrozen conditions were examined and evaluated. The objectives of this study were: (1) to construct SWRC using combined HYPROP and WP4 method, (2) to evaluate the soil water and temperature effects on the infiltration into frozen soil, and (3) to compare predicted hydraulic conductivity of three frozen soils of RRB with measured values using minidisk infiltrometer. It was found that HYPROP+WP4 combined method produced acceptable SWRC of RRB soils compared to other available traditional methods. However, shrinking and swelling of clay content of the soils might cause difference with in-situ measurement. Infiltration into frozen soil depended on initial soil water contents. The drier the frozen soil, the higher the infiltration rate. Soil water content changed gradually with rising temperature in a dry soil but in a frozen wet soil, it was very rapid due to the phase changing of water. The Horton infiltration model was fitted with measured frozen soil infiltration data with good agreement. Hydraulic conductivity of frozen soils decreased with an increase in soil water contents, but it was also subjected to sand and clay contents of the soil. Simple nonlinear regression model fitted with measured data and resulted reasonable agreement compared to Motivilov model. Freeze-thaw cycles altered the soil pore distribution, decreased the infiltration rate and hydraulic conductivity of frozen soils.
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Fritz, Heiko. "Infiltration in teilweise gefrorene Böden." Master's thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2010. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-62293.
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In der vorliegenden Arbeit wurden Doppelringinfiltrationsexperimente an teilweise gefrorenen Böden durchgeführt. Diese Experimente wurden anschließend mit den zwei computergestützten Modellen, Erosion 3D / Winter und COUP, nachgestellt, um die Frage zu beantworten, ob es möglich ist, die Infiltration in teilweise gefrorene Böden vorherzusagen.
Die Doppelringinfiltrationsexperimente wurden auf einem ackerbaulich genutzten Lehmboden mit geringer Lagerungsdichte und Bodenfeuchten im Bereich der Feldkapazität, an der nördlichen Grenze des hydrologischen Untersuchungsgebietes „Schäfertal“ durchgeführt. Drei Experimente erfolgten bei teilweise gefrorenen und ein Experiment bei ungefrorenem Boden.
Bei diesen Experimenten wurde herausgefunden, dass die Endinfiltrationsrate des gefrorenen Bodens mit 7·10-5 m/s gleich der Endinfiltrationsrate des ungefrorenen Bodens war. Während bei dem Infiltrationsexperiment mit ungefrorenem Boden die Endinfiltrationsrate bereits nach 10 bis 20 min erreicht war, wurden bei den Experimenten mit gefrorenen Böden aufgrund der zusätzlichen Sättigung des kryoturbativen Sekundärporenvolumens mehr Zeit benötigt.
Zu den im Boden ablaufenden Prozessen bei Zugabe von Infiltrationswasser (Temperaturveränderung, Gefrier- und Auftauprozesse, Veränderung der Porosität) besteht noch Klärungsbedarf.
Der für die Modellierung wichtige Eingabeparameter der Anfangsbodenfeuchte konnte bei winterlichen Bedingungen nicht genau bestimmt werden. Gravimetrische Bodenfeuchtebestimmungen liefern aufgrund des Eintrags von zusätzlichen Eis- und Schnee-Wasser zu hohe Werte. TDR- und Watermark-Messungen unterschätzen hingegen die Bodenfeuchten, weil sie nur den Anteil des flüssigen Wassers berücksichtigen.
Mit Erosion 3D / Winter konnten die Ergebnisse der Infiltrationsexperimente, unter der Voraussetzung, dass die effektive gesättigte hydraulische Leitfähigkeit des ungefrorenen Bodens exakt bekannt war, sehr gut nachgestellt werden. Eine Modellierung der Infiltration in einen teilweise gefrorenen Boden ist damit, zumindest für den untersuchten Boden und die betrachteten meteorologischen Bedingungen, möglich.
Das COUP - Modell lieferte dagegen völlig andere Ergebnisse, weil von einem Einfrieren des infiltrierten Wassers bei negativen Temperaturen ausgegangen wird. Eine Verbesserung der Infiltrationsbeschreibungen könnte hier wahrscheinlich durch die Vorgabe einer größeren Anzahl von Eingabeparametern, die die natürliche Situation besser repräsentieren als die für die Modellierung verwendeten Daten, erfolgen.
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Nguyen, Van Nghia. "Caractérisation de l'érosion des sols par le Jet Erosion Test." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2014. http://www.theses.fr/2014ECAP0043/document.
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Le contrôle de la sûreté des ouvrages hydrauliques est l’une des grandes priorité dans le domaine du génie civil et de l’ingénierie hydraulique. Durant sa vie, un ouvrage est soumis à des sollicitations variables hydromécaniques, physicochimiques et climatiques qui contribuent à son éventuelle détérioration. Parmi les phénomènes qui en résultent, l’érosion des sols sous toutes ses formes représente un enjeu majeur à comprendre, maîtriser et empêcher. L’objectif de ce travail est d’étudier l’érosion des sols par le Jet Erosion Test. La première partie est consacrée à la description des dispositifs expérimentaux, surtout le Jet Erosion Test (JET) développé à l’Ecole Centrale Paris permettant de mesurer directement quelques paramètres d’érosion. A partir des résultats du JET, à l’aide d’une loi d’érosion empirique, nous déduisons la contrainte de cisaillement critique, le coefficient d’érosion, la profondeur d’érosion d’équilibre. La deuxième partie du travail est consacrée à l’étude de l’influence des paramètres de compactage sur l’infiltration de l’eau et la résistance du sol, en utilisant le pénétromètre. Dans les troisième et quatrième parties, nous étudions l’influence des propriétés géotechniques du sol et celle des paramètres d’essai sur les paramètres d’érosion du sol. Les résultats obtenus montrent que les paramètres d’érosion sont influencés non seulement par les propriétés géotechniques du sol mais aussi par les paramètres d’essai. La dernière partie présente la synthèse entre les résultats des essais de pénétromètre et ceux des essai de JET, et tente de relier les paramètres d’érosion avec les propriétés géotechniques du solControl of the safety of hydraulic structures is a major priority in the field of civil and hydraulic engineering. During its life, the hydraulic structure is submitted to variable hydromechanical, physicochemical and climatic loads that may contribute to its possible failure. Among the resulting phenomena, soil erosion under all its forms is a major challenge which it is important to understand, control and prevent. The objective of this work is to study soil erosion by the Jet Erosion Test. The first part is devoted to the description of the experimental devices, especially the Jet Erosion Test (JET) developed at the Ecole Centrale Paris to directly measure some erosion parameters. From the results of JET, using an empirical erosion law, we deduce the critical shear stress, the erosion coefficient, the equilibrium scour depth. The second part of this work is devoted to the study of the influence of compaction parameters on water infiltration and soil strength, using the penetrometer. In the third and fourth parts, we study the influence of the geotechnical properties of soil and of the test parameters on the erosion parameters of soil. The obtained results show that the erosion parameters are influenced not only by the geotechnical properties of soil but also by the test parameters. The final section presents a synthesis of the results of penetrometer tests and JET tests, and attempts to link the erosion parameters with the geotechnical properties of soil
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Tsaparas, Ilias. "Field measurement and numerical modelling of infiltration and matric suctions within slopes." Thesis, Durham University, 2002. http://etheses.dur.ac.uk/1715/.
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Niziolomski, Joanna. "Optimising soil disturbance and mulch attenuation for erosion and runoff control in asparagus crops." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9209.
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Exposure of bare soil for long periods and onsite compaction create soil and water problems in asparagus production. This project aims to develop a cost effective and practical runoff and soil erosion management system. Two field trials (Phase 1 running from April - July 2012 and Phase 2 running from May - November 2013) tested different combinations of shallow soil disturbance (SSD) and mulch (straw and compost) application for soil erosion control. Cranfield University’s soil bin was used to test the effect of different tine configurations on soil disturbance. The results of this research corroborated observations that asparagus production can result in levels of unsustainable soil loss that will contribute to the degradation of the existing soil resource. The field trials demonstrated that a straw mulch applied at 6 t ha- 1 significantly improved key performance indicators (KPIs, i.e. runoff initiation, volume and rate; total soil loss; sediment concentration; total oxides of nitrogen; orthophosphate-P; and sediment-bound P) as compared with the Non-SSD Control. In general, SSD (irrespective of tine configuration) was ineffective at improving key performance indicators as compared with the Non-SSD Control. In the soil bin work, different tine configurations generated varying degrees and extent of SSD, with the modified para-plough giving the greatest soil disturbance for the least draught force. However, the differences in SSD observed in the soil bin had no effect on the KPI’s tested in the Phase 2 field trial. The effective treatments observed in the field trials only yielded cost savings to the farmer/grower when a high level of soil loss occurred. This research highlights the need to develop erosion control measures in asparagus fields, with wider implications to other row crops. However caution is needed, given the observed variation in effectiveness and reliability of in-field mitigation measures, especially during ‘extreme’ rainfall events.
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Silver, Robert Kenneth. "The compaction and permeability performance of mineral landfill liners." Thesis, University of the West of Scotland, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309630.
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Holden, Joseph. "Runoff production in blanket peat covered catchments." Thesis, Durham University, 2000. http://etheses.dur.ac.uk/4264/.
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Although blanket peat covers many major headwater areas in Britain, runoff production within these upland catchments is poorly understood. This thesis examines runoff production mechanisms within the blanket peat catchments of the Moor House National Nature Reserve, North Pennines, UK. Catchments ranging from 11.4 km^ down to the hillslope and plot-scale are examined. Runoff from the monitored catchments was flashy. Lag times are short and rainwater is efficiently transported via quickflow- generating mechanisms such that flood peaks are high and low flows poorly maintained. Hillslope and plot-scale runoff measurements show that the flashy catchment response is the result of the dominance of overland flow. Typically 80 % of runoff is produced as overland flow. This occurs both on bare and vegetated surfaces. Most of the remaining runoff is generated from the upper 10 cm of the peat, except where well-connected macropore and pipe networks transfer flow through the lower layers. Below 10 cm depth the blanket peat matrix fails to contribute any significant runoff Thus most groundwater-based models of peat hydrological process are not readily applicable to these catchments. Suggestions that infiltration-excess overland flow may be largely responsible for the flashy regime of these upland catchments are not substantiated by the blanket peat infiltration data presented in this thesis. Monitoring of hillslope runoff mechanisms combined with rainfall simulation (at realistic intensities of 3-12 mm hr(^-1)) and tension- infiltrometer experiments shows that saturation-excess mechanisms dominate the response. Infiltration is relatively rapid in the upper peat layers until they become saturated and overland flow begins. High water tables result in rapid saturation of the peat mass such that even at low rainfall intensity runoff production is just as efficient as during high intensity events. While macropores have largely been ignored in blanket peat, results presented suggest that up to 30 % of runoff may be generated through them. Occasionally these macropore networks develop through the deeper peat such that runoff bypasses the matrix and runs off at depth from small outlets and larger pipe networks. Seasonal variations in runoff- generating processes can be exacerbated by drought which causes structural changes to the near-surface of the peat. This was found to result in enhanced infiltration and macropore flow which may encourage pipe network development. Flow has been monitored simultaneously from several natural pipes in a 0.4 km(^2) headwater catchment of the Tees. This catchment provides one of the few examples of pipeflow monitoring outside the shallow peaty-podzols of mid-Wales. Natural pipes are found throughout the soil profile and can be at depths of up to three metres. Ground penetrating radar was useful in identifying deep subsurface piping and suggestions are made for improvements to the application. The pipe networks were found to be complex and results demonstrate that outlet location and size may bear little relation to the form and depth of the pipe a short distance upslope. Pipes generally contribute less than 10 % to catchment runoff but on the rising and falling hydrograph limbs can contribute over 30 % to streamflow. Pipeflow lag times are short suggesting that both the shallow and deep pipes may be well connected to the surface. Thus while matrix runoff contributions at depth within the peat may be low, macropore flow mechanisms can be significant.
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Nasri, Behzad. "Évaluation des fonctions de pédotransfert d’un sol hétérogène, milieu récepteur d’eau usée traitée, sur un site pilote dédié." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1180/document.
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Cette thèse a été effectuée dans le cadre du projet ANCRES. Son rôle est d'assurer la compréhension physique du milieu récepteur, le sol, alors qu'une autre équipe étudie l'impact physico-chimique des eaux usées traitées sur le sol. Pour cela, il faut connaître ses propriétés texturales et structurales contrôlant ses fonctions d'épuration et d'évacuation. La problématique est donc de comprendre le processus de l'infiltration imposée par un dispositif d'ANC dans un sol caillouteux. D'abord, suite au positionnement du site pilote d'ANC au pied d'un versant au cœur du plateau portlandien dans le département de l'Yonne en France, on a identifié là un type de sol hétérogène et complexe, caillouteux, une colluvion qui n'était pas cartographiée sur la carte géologique BRGM de cette région et sur laquelle on focalise la thèse. Ensuite, dans le sol complexe du site pilote, on a d'abord mesuré la conductivité hydraulique du sol par l'appareil Guelph sur 15 m² de la fouille de l'ANC à une profondeur de 120 cm : au total, on a fait 15 essais d'infiltration. De plus, on a récupéré 15 échantillons du sol accompagnant ses essais de Guelph pour la caractérisation physique au laboratoire. On a mesuré la texture, l'humidité résiduelle (HR), la teneur en cailloux (Rw) et la matière organique (MO) des échantillons au laboratoire. Ensuite, pour l'étude du processus d'infiltration, on a instrumenté ce site par un dispositif de surveillance hydrique (tensiométrie, teneur en eau, piézométrie) et de prélèvement d'eau interstitielle du sol. De plus, la masse volumique (densité) apparente d'un sol hétérogène a été déterminée. Parmi les paramètres mesurés, certains sont choisis comme indicateurs pour caractériser un sol comme milieu récepteur potentiel des eaux usées traitées en ANC. Puis, en utilisant la MO et la texture des échantillons, on a estimé la masse volumique apparente de la matrice du sol du site piloteau moyen de fonctions de pédotransfert appelées BD-FPTs et on a testé la relation entre la conductivité hydraulique à saturation Ks et la texture de ce sol complexe. Pour cela, une méthodologie en quatre phases a été développée pour évaluer la capacité prédictive des fonctions Ks-FPTs. Cette méthodologie de sélection n'a pas été trouvée dans la littérature mais est élaborée pour les besoins de la thèse. On a déduit les meilleures Ks-FPTs pour ce type de sol. Enfin, avec les données d'humidité volumique et du potentiel matriciel du sol, acquises par une centrale d'acquisition des données, le régime hydrodynamique du sol sous le massif filtrant de l'ANC a été étudié et on a mis en évidence l'écoulement préférentiel dans un sol caillouteux. Les résultats ont montré que dans la colluvion, bien que la matrice du sol soit fine, la conductivité hydraulique mesurée est plus élevée qu'attendu. Cela démontre que la fraction des cailloux dans le sol joue un rôle essentiel en accélérant l'évacuation des eaux usées traitées et aussi l'eau pluviale vers les couches sous-jacentes, et finalement vers la nappe. Cette propriété serait un point fort pour la fonction de transfert du sol et on peut en déduire une méthode pour améliorer la capacité de transfert de l'eau des sols lourds dans les projets d'aménagement urbain ou périurbain : l'ajout de graviers et graves calcaires par mélange au sol en place. On conclut que cette expérimentation, unique en son genre, a été utile pour évaluer la fonction de rétention / transfert de l'eau dans le sol recevant les eaux usées traitées. On a identifié les paramètres prédicteurs pertinents et les relations empiriques qui permettent de faire l'économie de nombreux essais in situ d'eauThe soil is an essential compartment in hydrologic cycle of water in the nature. Therefore, it is clear that taking into account the properties and organization of the soil is essential to the understanding and management of flows involved in the development of the quality of groundwater and surface water. The on-site sanitation (ANC) is a management method of domestic wastewater, by which the water is sent into the soil after settling and filtration liquefaction / aerobic degradation. The second step was often provided by the top soil in place himself, and this continues to this day on many plots of on-site sanitation.This thesis was carried out under ANCRES project. Its role was to ensure the physical understanding of the receptor medium, soil, while another research team was investigating the physico-chemical impact of treated wastewater on the sol. To ensure it, we have to understand its textural and structural properties controlling its purifying power and hydrodynamic processes. So, the problematic is to understand the process of infiltration imposed by an ANC in a heterogeneous stony soil. At first, due to the positioning of the pilot ANC site, at the foot of a slope in the Yonne department in France, a type of complex and heterogeneous soil, a colluvion, was identified. This soil has not been mapped on the BRGM (Bureau de recherches géologiques et minières) geological map of the area. So, the thesis was focalised on this soil. Then, in this soil complex at a depth of the 120 cm of the excavation of the ANC, the soil hydraulic conductivity was first measured by a Guelph apparatus on 15 m². We totally made 15 infiltration tests. Furthermore, we have collected 15 soil samples with each Guelph test for physics laboratory physical characterization. Then, in order to study the soil functions, this site was instrumented by the water monitoring devices (tensiometers, water content probes, and piezometer) and the interstitial water sampling device from the soil. In addition, the bulk of this heterogeneous soil was determined. Among the measured parameters, a series of indicators chosen to characterize the soil as a potential receptor medium of treated wastewater of the ANC. Then, the bulk density of the soil matrix using pedotransfer functions called BD-FPTs was estimated and the relationship between saturated hydraulic conductivity Ks and the texture of the soil complex (by Ks-FPT function) was tested. For this aim, a four-phase methodology was developed to assess the predictive ability of Ks- FPTs functions. This methodology in four phases is not found in the literature but was prepared for the purposes of the thesis. We concluded the best Ks- FPTS for this type of soil. Finally, with the volumetric water content and soil matrix potential data acquired by a the data loggers, the hydrodynamic regime of the soil under the sand pack of the ANC has been studied and demonstrated the preferential flow in a stony soil was demonstrated. The results showed that in the colluvion, although the soil matrix is fine, the measured hydraulic conductivity is higher than expected. This shows that the stone fraction in the soil plays an important role in accelerating the evacuation of treated wastewater and also rainwater to the underlying layers, and finally to the water table. This property would be a strong point for the transfer function of the soil and we can deduce a method to improve the transfer function of heavy soils in urban or peri-urban development projects. This could be possible by adding the gravel and -limestone to soil matrix and mixing them. It has been concluded that this experiment, unique in its kind, has been useful in evaluating the function of retention / transfer of water in the soil receiving treated wastewater. In addition, the relevant predictor parameters and empirical relationships that make the economy of many water tests were identified
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Madsen, Matthew David. "Measurement of Fine Spatial Scale Ecohydrologic Gradients in a Pinyon-Juniper Ecosystem." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/24.
Full textAbstract:
With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, a new method to precisely determine saturated hydraulic conductivity from small intact soil cores collected in the field is demonstrated. This method removes bias due to measurement error using a multiple head linear regression approach. Finally, hundreds of fine spatial scale measurements of soil sorptivity, unsaturated hydraulic conductivity, saturated hydraulic conductivity, soil water content, and other soil descriptive measurements along radial line transects extending out from the trunk of juniper (Juniperus osteosperma) and pinyon pine (Pinus edulis) trees. Within the subcanopy of these trees, interactions among litter material, root distributions, and hydrophobic soil significantly influence ecohydrologic properties by limiting and redirecting infiltration below the soil surface. Consequently, hydrophobicity appears to be a mechanism that promotes survival of woody vegetation in arid environments, through decreasing evaporation rates from the soil surface. We further demonstrate how differences in unsaturated infiltration and soil water content between the subcanopy and intercanopy zones are not discrete. Unsaturated infiltration was significantly lower within the subcanopy than in the intercanopy, and increased by eight-fold across a gradient extending outward from near the edge of the canopy to approximately two times the canopy radius. This gradient was not strongly related to soil moisture. In the intercanopy, increasing structural development of biological soil crust cover beyond this gradient was positivity correlated with infiltration capacity. Consequently, these results indicate that the spatial location of the trees should be considered in the assessment and modeling of woody plant and biological soil crust influence on infiltration capacity in a pinyon-juniper ecosystem.
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Harper, John, Jack Watson, and Tom Doerge. "The Effect of Gypsum and Sulfuric Acid Soil Amendments on the Yield of Alfalfa and Soil Infiltration Rates: A Progress Report." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/203795.
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Hanson, Nathan T. "Characterization and Removal Efficiency Comparison of Bioretention Soil Media Mixtures." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/1891.
Full textAbstract:
Bioretention cells have become a commonly used green infrastructure technique to help infiltrate and remove contaminants from stormwater runoff. Bioretention cells are constructed from a layered or heterogeneous soil mixture designed to optimize their ability to infiltrate influent stormwater and remove contaminants carried by the water as it filters through the soil media. The soil mixture, composition, and planting vary depending the local regulatory agencies. As urbanization occurs across the United States, more natural land is converted from pervious surfaces, such as grasslands and forests, to impervious surfaces such as asphalt and concrete, to help reduce the impact of the runoff generated by this increased flow bioretention cells are an often-used method to treat stormwater. These impervious surfaces do not allow rainfall to infiltrate, and the water runs off into receiving water bodies such as rivers and streams as a non-point source pollutant. To help reduce pollutant loadings into receiving water bodies, Low Impact Development (LID) techniques were developed to reduce stormwater volume, peak flow, and contaminant loading rates. The bioretention cell is one of the most popular LID techniques and is comprised of a soil media that is either a layered or homogenous media, which is built following a regional agency’s standard. The performance of bioretention soil media is highly variable depending on the amount of each soil constituent present in the media.
This study compares five different soil mixtures from various agencies’ specifications to determine which media composition is most effective at removing total suspended solids (TSS) and nitrates, two of the most prevalent contaminates carried by stormwater. This study also compares mixtures’ hydraulic conductivity which determines the volume of water that the media can infiltrate and “treat”. To perform these tests, six columns of soil media were constructed with media depths of 91.5 cm (36 inches). Columns were dosed with either tap water (Phase I) or a synthetic stormwater blend (Phase II) to determine the amount of TSS and nitrate exported by each mixture. The soil mixture in each column was characterized to understand how soil characteristics effect the performance of the various media mixtures.
The bioretention soil media columns were all shown to be effective at removing influent TSS with an average removal rate of over 88% across all the columns, ranging from 99.9% removal to 73.6% removal. Most bioretention soil mixtures used in the test were shown to be ineffective at removing influent nitrates, with breakthrough of nitrate occurring after the first two pore volumes. Interestingly, the media with higher organic content were more effective at removing nitrates, with removal rates as high as 59.9% compared to the media with lower organic content. Hydraulic conductivity was also highly variable across the various soil media mixtures depending on the percentage of sand and fine media particles present in the media. Hydraulic conductivity ranged from a high value of 42 cm/hr to a low of 8.3 cm/hr. By comparing these results, a more effective bioretention soil media mixture can become agency standard and allow bioretention cells to have more consistent and better performance.
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Warnana, Dwa Desa. "Rainwater infiltration and seismicity induced slope stability on residual soil using resistivity and microtremor measurements." Paris 6, 2013. http://www.theses.fr/2013PA066701.
Full textAbstract:
On évalue dans ce travail, en saison sèche comme en saison humide, la stabilité des pentes face à l’infiltration de la pluie et à l’activité sismique. Deux méthodes sont utilisées : la mesure de la résistivité électrique et celle des micro-trémors. Elles ont été mise en œuvre à Kemuning Lor Arjasa, Jember et Sumber Aji, Batu Malang. Les paramètres géotechniques et la résistivité des sols sont aussi analysés au laboratoire. Les données ainsi acquises, appuyées sur les modèles pétro-physiques, ont permis de proposer une interprétation quantitative de la structure du sous-sol. La mesure des micro-trémors est utilisée pour mieux comprendre les effets des tremblements de terre, définir des périodes propres des sites et localiser les pics d’amplitude (méthode du rapport déplacement horizontal sur déplacement vertical). On a pu ainsi proposer un indice de vulnérabilité et un déplacement en cisaillement. Les effets de la teneur en eau, de la cohésion, du poids spécifique et de l’angle de friction sur la résistivité électrique ont été précisés et un facteur empirique de sécurité a été déterminé et appliqué au suivi de résistivité en 2D en chaque lieu A Jember la pente est critique en saison humide. L’instabilité de pente induite par les séismes a pu être évaluée à partir de l’indice de vulnérabilité, elle est plus grande en saison humide qu’en saison sècheThis study aims to assess in the dry and rainy seasons the stability of slopes due to rain water infiltration and seismicity using resistivity and micro-tremor methods in Kemuning Lor Arjasa, Jember and Sumber Aji, Batu Malang. Geotechnical parameters and resistivity measurements in laboratory had also been carried out. A more detailed subsurface image deriving resistivity is verified to obtain quantitatively interpretation using geotechnical measurements and laboratory data as well as a petro-physical relation constitutive model. Microtremor measurements are used to better understand the soil effect induced by earthquakes. Hence, site period and peak amplitude is estimated from horizontal to vertical spectral ratio (HVSR) at study site. Finally, the slope stability that depends on soil vulnerability index and shear strain is able to calculate. The effects of moisture content, cohesion, unit weight, and friction angle on soil resistivity were determined. An empirical safety factor equation based on the rainwater infiltration-resistivity interaction and slope angles were determined and applied to 2-D resistivity monitoring in each location. It had been found that Jember slope was critical in the rainy season. The earthquake induced slope stability is assessed using the calculation of the soil vulnerability index and shear strain from microtremor measurements. The earthquake induced slope stability in the rainy season is found to be more vulnerable than in the dry season
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Engström, Linda. "Enskilda avlopp i Nordmalings kommun : Status, skyddsnivåer och teknikval i olika jordartsområden." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96223.
Full textAbstract:
The purpose of this study was to describe a) the status of the household sewage systems in the municipality of Nordmaling, b) to suggest areas in which a higher level of protection would be required and c) to investigate which type of technological choice was appropriate for which type of soil. A survey was used to investigate the status of the household sewage systems. The status was judged mainly on the age and treatment of water. Protected areas, the ecological status and data for phosphorus and nitrogen were used to locate areas in need of a higher protection. Map data from the Geological Survey of Sweden was used to identify common soil types in Nordmaling. Subsequently, the map was complemented and verified with a field investigation. In a next step, characteristics of the soil types were compared to the requirements of four different sewage treatment technologies; infiltration, constructed infiltration, incinerator toilets and household sewage plants. The study shows that the household sewage systems in Nordmaling are in general not in a good condition. Almost 70 % of the sewage systems are older than 20 years and their function is likely not sufficient. The study suggests that the following areas should be included in the list of objects with high protection: Lögde- and Öre river, Kronören, Järnäs peninsula, waters with an ecological status below “good” and the protected water resources. Except for infiltration, all sewage treatment technologies were assumed to give appropriate results for all soil types.
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Shetterly, Benjamin James. "Soil Phosphorus Characterization and Vulnerability to Release in Urban Stormwater Bioretention Facilities." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4354.
Full textAbstract:
Modern urban stormwater infrastructure includes vegetated bioretention facilities (BRFs) that are designed to detain water and pollutants. Phosphorus (P) is a pollutant in stormwater which can be retained in BRF soils in mineral, plant, and microbial pools. We explored soil properties and phosphorus forms in the soils of 16 operational BRFs in Portland, OR. Since soil hydrology can significantly impact P retention, we selected BRFs along an infiltration rate (IR) gradient. We conducted sequential fractionation and tests of P pools and measured P release in a subset of soils after drying and flooding samples for ten days. We hypothesized that mineral or organic soil P forms would be correlated with IR, and that vulnerability to P release would depend on the interaction of drying and flooding treatments with P forms and pools. IR did not significantly explain differences in P forms. Soil TP was elevated across all sites, compared with TP in agriculturally-impacted wetlands and was substantially composed of soil organic matter (OM)-associated P. Phosphorus sorbed to mineral Fe and Al oxides- was variable but positively correlated with water-extractable P. The concentration gradient of water-extractable P was primarily controlled by overall P pools. Experimentally induced P releases were seen in 5 of 6 soils exposed to drying conditions, presumably released through microbial mineralization of OM. Only one site showed significant P release following the flooding treatment. Our measurements supported the idea that Fe and Al oxides provide P sorption capacity in these BRF soils. Variable inputs of P to BRFs through stormwater and litterfall may contribute to variability in P profiles and P release vulnerability across sites. Design specifications and management decisions relating to bioretention soils (e.g. establishment of acceptable soil test P levels, focusing on P forms known to influence vulnerability of P release) may benefit from detailed biogeochemical investigations.
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Kim, Sang Dan. "The upscaling of one-dimensional unsaturated soil water flow model under infiltration and evapotranspiration boundary conditions /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Baratta, Vanessa Marrie. "The Effects of Freeze-Thaw Cycles on the Infiltration Rates of Three Bioretention Cell Soil Mixtures." Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/4819.
Full textAbstract:
The expansion of urban and suburban areas is a world-wide phenomena. One product of this development is a dramatic increase in impermeable surfaces and a consequent increase in stormwater runoff. Bioretention cells are one best management practice frequently used to mitigate the environmental impacts of urban stormwater runoff. To ensure that a bioretention cell will continue to perform adequately in the long term, it is imperative that the environmental conditions it will experience and their effect on its performance through time are considered during its design. Although bioretention cells are frequently used for stormwater management, very few quantitative data exist on how they perform through time and in varied physical environments. In regions with seasonal freeze-thaw cycles, it is important to understand the effects of freeze-thaw cycles on the infiltration rate of bioretention cell soil mixtures so that the integrity of the design will not be compromised by seasonal change.
This project uses laboratory tests to investigate the effects of freeze-thaw cycles and sediment input on the infiltration capacity of three different bioretention cell soil mixtures. These results will provide an analog for long-term changes in bioretention cell infiltration rates due to freeze-thaw cycles, providing critical data on which soil mixture would be best implemented in geographic regions susceptible to freeze-thaw activity. Furthermore these results will inform design standards for bioretention cells to ensure their long-term performance.
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Rachman, Seaful, and n/a. "Infiltration under different landuse types at the Upper Ciliwung watershed of West Java, Indonesia." University of Canberra. School of Resource, Environmental and Heritage Sciences, 1992. http://erl.canberra.edu.au./public/adt-AUC20041215.124610.
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Infiltration, the process of water movement through the soil surface is one of most important hydrological processes to be considered in watershed management. The process depends on rainfall, soil, vegetation and
topographic conditions. The last three variables can be influenced by human land-uses. This study is concerned with the influence of landuse
types (categories) on infiltration at the upper
Ciliwung watershed of West-Java, Indonesia. Sixty six infiltration measurements were carried out in 5 types of land-uses i.e. natural forest, agriculture, settlement, productive (old) tea and new tea plantation areas. The measurements were done using ring infiltrometers. The data
obtained were expressed in the form of Philip's equation I = st1I2 + At, where I is cumulative infiltration; S is sorptivity; t is time; A is a parameter which was calculated from saturated hydraulic conductivity (K). Crown cover, slope gradient and soil variables such as soil moisture, organic carbon content, total porosity,
bulk density were also analysed from each of the 66 sites. The results of the study shows that land-use types have significant influence on these soil variables and on infiltration. Crown cover and human activities in term of land management are among the most important factors which affect soil condition. These variables mostly influence total porosity of soil which is the most important variable to determine sorptivity and hydraulic conductivity. High percentage of crown cover and less human activity
in forest area result in high accumulation of litter and humus and high total porosity of soil. On the other hand, settlement and new tea plantation areas have comparatively low crown cover and more frequent human activity which
result in soil compaction. Discriminant function analysis of land-use categories shows that the soil under forest is very distinct from the soils under other land-use types. However, the soils under the remaining land-use types are
more similar to each other, especially between the soil of settlement and tea plantations.
The rank of infiltration rate from the highest to the lowest magnitude is as follows; natural forest, agriculture, productive tea plantation, new tea plantation and settlement areas. Infiltration rates under natural forest and agriculture are significantly different from each
other as well as from those in the last three land- use types. However, there are no significant differences in infiltration rates among the last three land-use types. The result of this study also provides basic information
for landuse management and further research in
order to solve soil and water conservation and management problems in the watershed.
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O'Reilly, Andrew M. "Biogeochemical Cycling and Nutrient Control Strategies for Groundwater at Stormwater Infiltration Basins." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5360.
Full textAbstract:
Elevated concentrations of nutrients, particularly nitrate, in groundwater and springs in Florida are a growing resource management concern. Stormwater infiltration basins, which are a common stormwater management practice in the well-drained karst terrain areas of Florida, are a potentially important source of nutrients to the groundwater system because stormwater exits the basin by only evaporation or infiltration. To better understand the biogeochemical processes integrating stormwater infiltration impacts on groundwater resources in a field-scale setting, a combination of hydrologic, soil chemistry, water chemistry, dissolved and soil gas, isotope, and microbiological data was collected from 2007 through 2010 at two stormwater infiltration basins receiving runoff from predominantly residential watersheds in north-central Florida. Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath the two stormwater infiltration basins. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median 41% silt+clay content) exhibited decreases in dissolved oxygen from 3.8 to 0.1 mg/L and decreases in nitrate-nitrogen from 2.7 mg/L to less than 0.016 mg/L, followed by manganese and iron reduction, sulfate reduction, and methanogenesis. In contrast, beneath the basin with predominantly sandy soils (median 2% silt+clay content), aerobic conditions persisted from 2007 through 2009 (dissolved oxygen of 5.0–7.8 mg/L), resulting in nitrate-nitrogen of 1.3–3.3 mg/L in shallow groundwater. Soil extractable nitrate-nitrogen was significantly lower and the copper-containing nitrite reductase gene density was significantly higher beneath the clayey basin. Differences in moisture retention capacity between fine- and coarse-textured soils resulted in median volumetric gas-phase contents of 0.04 beneath the clayey basin and 0.19 beneath the sandy basin, inhibiting surface/subsurface oxygen exchange beneath the clayey basin. Subsurface biogeochemical processes at the clayey stormwater infiltration basin were further analyzed to better understand the effects of the highly variable hydrologic conditions common in humid, subtropical climates. Cyclic variations in biogeochemical processes generally coincided with wet and dry hydroclimatic conditions. Oxidizing conditions in the subsurface persisted for about one month or less at the beginning of wet periods with dissolved oxygen and nitrate showing similar temporal patterns. Reducing conditions in the subsurface evolved during prolonged flooding of the basin. At about the same time oxygen and nitrate reduction concluded, manganese, iron, and sulfate reduction began, with the onset of methanogenesis one month later. Reducing conditions persisted up to six months, continuing into subsequent dry periods until the next major oxidizing infiltration event. Evidence of denitrification in shallow groundwater at the site is supported by median nitrate-nitrogen less than 0.016 mg/L, excess nitrogen gas up to 3 mg/L progressively enriched in delta-15N during prolonged basin flooding, and isotopically heavy delta-15N and delta-18O of nitrate (up to 25 and 15 per mil, respectively). Isotopic enrichment of newly infiltrated stormwater suggests denitrification was partially completed within two days. Soil and water chemistry data suggest a biogeochemically active zone exists in the upper 1.4 m of soil, where organic carbon was the likely electron donor supplied by organic matter in soil solids or dissolved in infiltrating stormwater. The cyclic nature of reducing conditions effectively controlled the nitrogen cycle, switching nitrogen fate beneath the basin from nitrate leaching to reduction in the shallow saturated zone. Soil beneath the sandy stormwater infiltration basin was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop an innovative best management practice (BMP) utilizing nutrient reduction and flood control sub-basins. Construction and materials costs, excluding profit and permit fees, for the innovative BMP were about $US 65 per square meter of basin bottom. Comparison of nitrate/chloride ratios for the shallow groundwater indicate that prior to using BAM, nitrate concentrations were substantially influenced by nitrification or variations in nitrate input. In contrast, for the new basin utilizing BAM, nitrate/chloride ratios indicate minor nitrification and nitrate losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest nitrate losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium and plant uptake are minor processes. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM orthophosphate/chloride ratios for shallow groundwater indicate predominantly minor increases and decreases in orthophosphate with the exception of one summer sample that indicated a 50% loss. Differences in nutrient variations between the unsaturated zone and shallow groundwater may be the result of the intensity and duration of nutrient removal processes and mixing ratios with water that had undergone little biogeochemical transformation. In order to quantify potential processes leading to observed nitrogen losses beneath the innovative BMP, an integrated infiltration basin–nitrogen reduction (IBNR) system dynamics model was developed. Based on two simulation periods, the IBNR model indicated denitrification accounted for a loss of about one-third of the total dissolved nitrogen mass inflow and was occurring predominantly in the BAM layer. The IBNR model results in combination with the field-based biogeochemical assessment demonstrated that the innovative BMP using the functionalized soil amendment BAM is a promising passive, economical, stormwater nutrient-treatment technology. Further field- and laboratory-scale research on the long-term sustainability of nutrient losses and further elucidation of causative physicochemical and biogeochemical mechanisms would contribute to improved BAM performance and green infrastructure development in the future.ID: 031001572; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: Ni-Bin Chang.; Title from PDF title page (viewed August 26, 2013).; Thesis (Ph.D.)--University of Central Florida, 2012.; Includes bibliographical references (p. 246-263).
Ph.D.
Doctorate
Civil, Environmental, and Construction Engineering
Engineering and Computer Science
Civil Engineering
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Kumar, Vivek. "Hydro-Physical Characterization of Media Used in Agricultural Systems to Develop the Best Management Practices for operation of an Environmentally Sustainable Agricultural Enterprise." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/787.
Full textAbstract:
Florida is the second leading horticulture state in the United States with a total annual industry sale of over $12 Billion. Due to its competitive nature, agricultural plant production represents an extremely intensive practice with large amounts of water and fertilizer usage. Agrochemical and water management are vital for efficient functioning of any agricultural enterprise, and the subsequent nutrient loading from such agricultural practices has been a concern for environmentalists. A thorough understanding of the agrochemical and the soil amendments used in these agricultural systems is of special interest as contamination of soils can cause surface and groundwater pollution leading to ecosystem toxicity. The presence of fragile ecosystems such as the Everglades, Biscayne Bay and Big Cypress near enterprises that use such agricultural systems makes the whole issue even more imminent.
Although significant research has been conducted with soils and soil mix, there is no acceptable method for determining the hydraulic properties of mixtures that have been subjected to organic and inorganic soil amendments. Hydro-physical characterization of such mixtures can facilitate the understanding of water retention and permeation characteristics of the commonly used mix which can further allow modeling of soil water interactions.
The objective of this study was to characterize some of the locally and commercially available plant growth mixtures for their hydro-physical properties and develop mathematical models to correlate these acquired basic properties to the hydraulic conductivity of the mixture. The objective was also to model the response patterns of soil amendments present in those mixtures to different water and fertilizer use scenarios using the characterized hydro-physical properties with the help of Everglades-Agro-Hydrology Model.
The presence of organic amendments helps the mixtures retain more water while the inorganic amendments tend to adsorb more nutrients due to their high surface area. The results of these types of characterization can provide a scientific basis for understanding the non-point source water pollution from horticulture production systems and assist in the development of the best management practices for the operation of environmentally sustainable agricultural enterprise
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JUNIOR, FRANCISCO DE ASSIS COSTA. "STUDY OF THE EFFECT OF INFILTRATION OF CAUSTIC SODA ON THE STRENGTH CHARACTERISTICS OF A LATERITIC SOIL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2001. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2064@1.
Full textAbstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOREste trabalho apresenta um estudo do comportamento mecânico, em especial nas características de resistência, de um solo laterítico submetido à contaminação de licores cáusticos a diferentes concentrações. O programa experimental envolveu ensaios de caracterização, ensaios químicos, difração de raios-X, microscopia eletrônica de varredura e ensaios triaxiais com diferentes valores de concentrações cáusticas. Propriedades mecânicas foram determinadas mediante a execução de ensaios triaxiais CID a diferentes concentrações cáusticas, assim como as interações físico- químicas que foram determinadas mediante ensaios químicos de pH, capacidade de troca catiônica e ataque sulfúrico. Os resultados do programa experimental demonstraram uma acentuada variação de volume do solo, a qual está ligada à presença dos licores cáusticos e, por outro lado, também indicaram que os parâmetros de resistência ao cisalhamento do solo são pouco afetados pelos licores cáusticos.
This work presents the results of a laboratory study on the effects of infiltration of a caustic liqueur on the stress- strain- strength behavior of a sandy lateritic soil. The experimental program consisted of general characterization,chemicals tests, X-ray diffraction analysis, electron microscopy and triaxial tests using the caustic liqueur at different concentrations.Mechanic and hydraulic properties were obtained performing triaxial CID tests with different caustic concentrations. Physical- chemical interactions were evaluated through of determination of pH, cation exchange capacity and sulfuric attack tests. The results obtained showed that soil suffers large volume changes under percolation of the liqueur, with these changes being a function of the caustic concentration, on the other hand, the shear strength parameters are little affected by the liqueur.
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Lee, Hock Seng. "An ODE/MOL PDE Template For Soil Physics." Thesis, Griffith University, 2003. http://hdl.handle.net/10072/365588.
Full textAbstract:
The aim of the thesis is to find a method, in conjunction with the ordinary differential equation (ODE) based method of lines (MOL) solution of Richards’ equation, to model the steep wetting front infiltration in very dry soils, accurately and efficiently. Due to the steep pressure head or steep water volumetric content gradients, highly nonlinear soil hydraulic properties and the rapid movement of the wetting front, accurate solutions for infiltration into a dry soil are usually difficult to obtain. Additionally, such problems often require very small time steps and large computation times. As an enhancement to the used ODE/MOL approach, Higher Order Finite Differencing, Varying Order Finite Differencing, Vertical Scaling, Adaptive Schemes and Non-uniform Stretching Techniques have been implemented and tested in this thesis. Success has been found in the ability of Vertical Scaling to simulate very steep moving front solution for the Burgers’ equation. Unfortunately, the results also show that Vertical Scaling needs significant research and improvement before their full potential in routine applications for difficult nonlinear problems, such as Richard’s equation with very steep moving front solution, can be realized. However, we have also shown that the use of the composed form of RE and a 2nd order finite differencing for the first order derivative approximation is conducive for modelling steep moving front problem in a very dry soil. Additionally, with the combination of an optimal influx value at the edges of the inlet, the ODE/MOL approach is able to model a 2-D infiltration in very dry soils, effectively and accurately. Furthermore, one of the strengths of this thesis is the use of a MATLAB PDE template. Implementing the ODE/MOL approach via a MATLAB PDE template has shown to be most suitable for modelling of partial differential equations. The plug and play mode of modifying the PDE template for solving time-dependent partial differential equations is user-friendly and easy, as compared to more conventional approaches using Pascal, Fortran, C or C++. The template offers greater modularity, flexibility, versatility, and efficiency for solving PDE problems in both 1-D and 2-D spatial dimensions. Moreover, the 2-D PDE template has been extended for irregular shaped domains.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
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Stakland, Steven Keyes. "Effect of Mica Content on Surface Infiltration of Soils in Northwestern Kern County, California." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/840.
Full textAbstract:
A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used to increase IR such as using cover crops and increasing organic matter. Despite these different approaches to the problem, the specific cause of low IR is often unknown. This study was conducted to determine what physical properties of soils from a site in California cause low IR. This research shows the relationship of these properties to low IR.
It was assumed that high amounts of mica in the very fine sand and coarse silt fraction of soils in Northwestern Kern County, California may interact with other physical and chemical properties to reduce IR. Fourteen sites were sampled in the area near the towns of Wasco and Shafter. The soils sampled represented the typical agricultural soils of the area and exhibited three levels of infiltration, Good (no amendments), Moderate (requires gypsum), and Poor (gypsum application is insufficient). Mica percentages in the very fine sand and coarse silt were calculated using a petrographic microscope and compared to the overall IR of the fields. Mica was shown to be significant factor at all three levels of IR.
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Brevnova, Elena V. "Green-Ampt infiltration model parameter determination using SCS curve number (CN) and soil texture class, and application to the SCS runoff model." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2039.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2001.Title from document title page. Document formatted into pages; contains ix, 149 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 60-63).