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dc.contributor.advisorKachanoski, R. Garyen_US
dc.creatorWoods, Shelley Anneen_US
dc.date.accessioned2005-08-23T11:49:54Zen_US
dc.date.accessioned2013-01-04T04:54:04Z
dc.date.available2005-08-24T08:00:00Zen_US
dc.date.available2013-01-04T04:54:04Z
dc.date.created2005-07en_US
dc.date.issued2005-07-15en_US
dc.date.submittedJuly 2005en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-08232005-114954en_US
dc.description.abstractField-scale transport through unsaturated soil is influenced by surface and subsurface boundary conditions, and the spatial variability of state soil variables. The objective of this thesis is to examine the relative importance of the spatial redistribution of surface water versus spatial variability of soil properties on long-term transient water flow and transport under semi-arid conditions. The field-scale transport (34 yr) of a surface applied tracer (chloride), spatial variability of other pedogenic tracers, and surface water redistribution over a 19 mo fallow period were measured in a catchment basin. In 1966 and 1971, a chloride tracer (KCl) was surface applied to plots (6.1 m x 90 m, Chernozemic soil) near Saskatoon, Saskatchewan. In 2000 and 2001, 262 soil cores were taken along and perpendicular to one KCl strip. Soil layering at each core was recorded and samples were analysed for chloride concentration, electrical conductivity, bulk density and water content. Sulphate and nitrate concentrations were measured on selected cores. The site is level by common definitions, with a very slight concave depression (1.8% grade) midway along the KCl strip and a slight grade (¡Ü2.1%) perpendicular to the KCl strip. Measured water recharge indicated slight differences in surface slope had a marked effect on redistribution of water and spatial distribution of the chloride tracer. An estimated 90% of redistributed water was subsequently used by plants and 10% resulted in an increase in deep drainage. A varved layer had a strong influence on the subsurface redistribution of water and chloride below the root zone. There were sharp horizontal transitions between areas of slow and faster transport, which corresponded to sharp increases in catchment area and water recharge. Small surface depressions, which controlled pedogenic transport and soil formation, have been filled in by tillage translocation. Spatial variability of soil horizon thickness (and associated hydraulic properties) had little effect on transport of chloride after 34 yr. Computer simulations also suggest substantial surface redistribution of precipitation and snowmelt. In contrast to the measured chloride data, the model was sensitive to changes in hydraulic properties and horizon thickness in the root zone. Surface water redistribution was the primary factor controlling long-term transport.en_US
dc.language.isoen_USen_US
dc.subjectsolute transporten_US
dc.subjecttraceren_US
dc.subjectsemi-ariden_US
dc.subjecttransient flowen_US
dc.subjecttopographyen_US
dc.subjectwater redistributionen_US
dc.subjectvadose zoneen_US
dc.subjectchlorideen_US
dc.titleLong-term field-scale transport of a chloride tracer under transient, semi-arid conditionsen_US
thesis.degree.departmentSoil Scienceen_US
thesis.degree.disciplineSoil Scienceen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophy (Ph.D.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US


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