[-] Show simple item record

dc.contributor.advisorGantzer, Clark Jameseng
dc.contributor.authorLee, Sang Soo, 1978-eng
dc.date.issued2006eng
dc.date.submitted2006 Falleng
dc.descriptionThe 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.descriptionTitle from title screen of research.pdf file (viewed on August 24, 2007)eng
dc.descriptionVita.eng
dc.descriptionIncludes bibliographical references.eng
dc.descriptionThesis (M.S.) University of Missouri-Columbia 2006.eng
dc.descriptionDissertations, Academic -- University of Missouri--Columbia -- Soil, environmental and atmospheric sciences.eng
dc.description.abstractRainfall 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.b59445634eng
dc.identifier.oclc166290506eng
dc.identifier.otherLeeS-120706-T6024eng
dc.identifier.urihttp://hdl.handle.net/10355/4507eng
dc.publisherUniversity of Missouri--Columbiaeng
dc.relation.ispartofcollection2006 Freely available theses (MU)eng
dc.relation.ispartofcommunityUniversity of Missouri-Columbia. Graduate School. Theses and Dissertations. Theses. 2006 Theseseng
dc.subject.lcshSoil permeability -- Measurementeng
dc.subject.lcshSoil crustingeng
dc.subject.lcshSilt loameng
dc.subject.lcshRain and rainfalleng
dc.subject.lcshRunoffeng
dc.titleSoil surface-seal measurement using high-resolution x-ray computed tomography (HRCT)eng
dc.typeThesiseng
thesis.degree.disciplineSoil, environmental and atmospheric sciences (MU)eng
thesis.degree.grantorUniversity of Missouri--Columbiaeng
thesis.degree.levelMasterseng
thesis.degree.nameM.S.eng


Files in this item

[PDF]
[PDF]
[PDF]

This item appears in the following Collection(s)

[-] Show simple item record