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Experimental Studies on Infiltration/Soil-Water Movement Processes and Green-AMPT ModelingSande, Leif Andrew January 2011 (has links)
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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The coupled transport of water and heat in a vertical soil column under atmospheric excitationMilly, Paul Christopher Damian January 1980 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 150-155. / by Paul Christopher Damian Milly. / M.S.
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Thermodynamics of non-dilute saline solutions in variably saturated porous mediaBurns, Erick R. 27 September 2004 (has links)
Non-dilute salt strength solutions occur in many near surface geologic environments.
In order to better understand the occurrence and movement of the water and salt,
mathematical models for this non-ideal fluid need to be developed. Initial boundary
value problems may then be solved to predict behavior for comparison with
observations. Using the principles of equilibrium reversible and irreversible
thermodynamics, relationships describing the thermo-physics of non-dilute saline
solutions in variably saturated porous media are investigated. Each of four central
chapters investigates a particular aspect of the flow of saline solutions through porous
media. The first chapter derives the general relationships describing the effects of salt
on the vapor content in the gas phase and also on the liquid pressure. The second
chapter summarizes an example using the new theory for sodium chloride (NaCl) from
zero to saturated strength. Additional terms beyond the dilute approximation are
shown to be more important in very dry, fine textured soils with significant salt
content. The third chapter derives the salt corrections for Darcy-type flow laws for
variably saturated porous media, and an example for NaCl is given. Agreement
between theory and experimental data is good, though there appear to be some
unaccounted for effects. These effects may be the result of ionic interaction of the salt
with the loamy sand used, and/or the effect of hysteresis of the water content-pressure
relationship. The final chapter investigates two fundamental assumptions commonly
used in process thermodynamics when considering mixtures described by porous
media, saline water, and moist air. The first assumption is that temperature is the
generalized intensive variable associated with entropy. The second assumption is that
the form of the differential of total energy is known a-priori. It is shown that the first
assumption is suspect under some circumstances, and a generalized notion of how to
select extensive variables for a given system is introduced for comparison with the
second assumption. Examples comparing the "usual" and new theories are
accomplished for ideal gases and for isotropic Newtonian liquids, with results being
favorable except possibly for the Gibbs-Duhem Relation of the Newtonian liquid for
the "usual" theory. / Graduation date: 2005
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