dc.contributor.advisor | Gantzer, Clark James | eng |
dc.contributor.author | Lee, Sang Soo, 1978- | eng |
dc.date.issued | 2006 | eng |
dc.date.submitted | 2006 Fall | eng |
dc.description | The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. | eng |
dc.description | Title from title screen of research.pdf file (viewed on August 24, 2007) | eng |
dc.description | Vita. | eng |
dc.description | Includes bibliographical references. | eng |
dc.description | Thesis (M.S.) University of Missouri-Columbia 2006. | eng |
dc.description | Dissertations, Academic -- University of Missouri--Columbia -- Soil, environmental and atmospheric sciences. | eng |
dc.description.abstract | Rainfall on bare soil breaks soil aggregates, detaching particles, plugging pores and decreasing porosity in the top few mm of soil. This reduces hydraulic conductivity and increases runoff through a process known as surface sealing. The objectives of this study are to measure saturated hydraulic conductivity (Ksat) of surface seals developed on bare Mexico silt loam (Aeric Vertic Epiaqualfs) during a simulated rainfall event, to evaluate the effect of anionic polyacrylamide (PAM) for maintaining high Ksat, and to evaluate models of sealing using total porosity, pore-size distribution collected with high-resolution X-ray computed tomography (HRCT). The study used a factorial design. Factors included rainfall duration (0-, 7.5-, 15-, 30-, and 60-min) at 55-mm hr-1 intensity, and an untreated soil or a soil amended with 20-kg ha-1 PAM. Application of PAM for various rainfall durations maintained from 20% to 41% higher Ksat than did untreated soil, for all times tested. Results indicated density ([rho]) increased, and total porosity and pore-size decreased rapidly after a 15-min rainfall. HRCT-[rho] data helped identify the best model selection for characterizing seal [rho] profile. Although the cost is expensive, HRCT image is a valuable tool to measure soil properties by analyzing soil thickness down to 0.015-mm. The study confirms that HRCT-analysis of soil allows accurate and direct measurements of seal effects on water flow and documents the usefulness of PAM for reducing surface sealing. | eng |
dc.identifier.merlin | b59445634 | eng |
dc.identifier.oclc | 166290506 | eng |
dc.identifier.uri | https://hdl.handle.net/10355/4507 | |
dc.identifier.uri | https://doi.org/10.32469/10355/4507 | eng |
dc.language | English | eng |
dc.publisher | University of Missouri--Columbia | eng |
dc.relation.ispartofcommunity | University of Missouri--Columbia. Graduate School. Theses and Dissertations | eng |
dc.subject.lcsh | Soil permeability -- Measurement | eng |
dc.subject.lcsh | Soil crusting | eng |
dc.subject.lcsh | Silt loam | eng |
dc.subject.lcsh | Rain and rainfall | eng |
dc.subject.lcsh | Runoff | eng |
dc.title | Soil surface-seal measurement using high-resolution x-ray computed tomography (HRCT) | eng |
dc.type | Thesis | eng |
thesis.degree.discipline | Soil, environmental and atmospheric sciences (MU) | eng |
thesis.degree.grantor | University of Missouri--Columbia | eng |
thesis.degree.level | Masters | eng |
thesis.degree.name | M.S. | eng |