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A measure of soil structure derived ...

Rutgers The State University of New Jersey - New Brunswick., Graduate School - New Brunswick.

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A measure of soil structure derived from water retention properties: A Kullback-Leibler Distance approach.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	A measure of soil structure derived from water retention properties: A Kullback-Leibler Distance approach./
Author:	Yoon, Sung Won.
Description:	145 p.
Notes:	Adviser: Daniel Gimenez.
Contained By:	Dissertation Abstracts International70-06B.
Subject:	Agriculture, Soil Science. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoeng/servlet/advanced?query=3359187
ISBN:	9781109191974

A measure of soil structure derived from water retention properties: A Kullback-Leibler Distance approach.
Yoon, Sung Won.

A measure of soil structure derived from water retention properties: A Kullback-Leibler Distance approach. - 145 p.

Adviser: Daniel Gimenez.

Thesis (Ph.D.)--Rutgers The State University of New Jersey - New Brunswick, 2009.

Water retention curves of structured soils reflect the combined effects of pore systems associated to a given distribution of particle sizes (texture) and those that are the result of rearrangement of soil particles into soil structural units. The main hypothesis of this work was that the entropic distance between structural and textural soil pore systems can be a measure of soil structure. It was also hypothesized that such distance can be derived from water retention curves by assuming that both pore systems follow lognormal distributions and that textural pore systems are the result of random arrangements of particles sizes. The entropic difference between the distributions of the two pore systems considered was derived as a Kullback-Leibler Distance or KLD using an explicit equation that uses the geometric means and standard deviations of pores and particle size distributions derived from water retention data and from information on clay, silt and sand content. Data on water retention and texture obtained for this study was supplemented with data from the literature and with data on 1468 soils from the US National Pedon Characterization database. The KLD concept was tested by comparing physically disturbed samples with undisturbed samples over a range of soil structure conditions. Values of KLD from younger soils along two chronosequences, and from compacted and/or degraded soils were smaller than those from older soils and non compacted or degraded soils. Also, KLD values of disturbed samples were lower than those of undisturbed samples. The use of KLD in a large dataset showed that KLD was linearly related to saturated hydraulic conductivity, which is an important hydraulic property. Also, KLD was an important grouping factor in a regression tree analysis for estimation of water content at -33 kPa and in clusters defined from a combination of field and morphological variables. The KLD measure is a promising tool to characterize soil structure. Future studies should consider incorporating KLD into pedotransfer functions or other predictive schemes aimed at improving the estimation of hydraulic properties, which are sensitive to soil structure.

ISBN: 9781109191974Subjects--Topical Terms:

1017824
Agriculture, Soil Science.

A measure of soil structure derived from water retention properties: A Kullback-Leibler Distance approach.
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100 1 $a Yoon, Sung Won. $3 1029984
245 1 2 $a A measure of soil structure derived from water retention properties: A Kullback-Leibler Distance approach.
300 $a 145 p.
500 $a Adviser: Daniel Gimenez.
500 $a Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: .
502 $a Thesis (Ph.D.)--Rutgers The State University of New Jersey - New Brunswick, 2009.
520 $a Water retention curves of structured soils reflect the combined effects of pore systems associated to a given distribution of particle sizes (texture) and those that are the result of rearrangement of soil particles into soil structural units. The main hypothesis of this work was that the entropic distance between structural and textural soil pore systems can be a measure of soil structure. It was also hypothesized that such distance can be derived from water retention curves by assuming that both pore systems follow lognormal distributions and that textural pore systems are the result of random arrangements of particles sizes. The entropic difference between the distributions of the two pore systems considered was derived as a Kullback-Leibler Distance or KLD using an explicit equation that uses the geometric means and standard deviations of pores and particle size distributions derived from water retention data and from information on clay, silt and sand content. Data on water retention and texture obtained for this study was supplemented with data from the literature and with data on 1468 soils from the US National Pedon Characterization database. The KLD concept was tested by comparing physically disturbed samples with undisturbed samples over a range of soil structure conditions. Values of KLD from younger soils along two chronosequences, and from compacted and/or degraded soils were smaller than those from older soils and non compacted or degraded soils. Also, KLD values of disturbed samples were lower than those of undisturbed samples. The use of KLD in a large dataset showed that KLD was linearly related to saturated hydraulic conductivity, which is an important hydraulic property. Also, KLD was an important grouping factor in a regression tree analysis for estimation of water content at -33 kPa and in clusters defined from a combination of field and morphological variables. The KLD measure is a promising tool to characterize soil structure. Future studies should consider incorporating KLD into pedotransfer functions or other predictive schemes aimed at improving the estimation of hydraulic properties, which are sensitive to soil structure.
590 $a School code: 0190.
650 4 $a Agriculture, Soil Science. $3 1017824
650 4 $a Environmental Sciences. $3 676987
690 $a 0481
690 $a 0768
710 2 $a Rutgers The State University of New Jersey - New Brunswick. $b Graduate School - New Brunswick. $3 1019196
773 0 $t Dissertation Abstracts International $g 70-06B.
790 $a 0190
790 1 0 $a Gimenez, Daniel, $e advisor
791 $a Ph.D.
792 $a 2009
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoeng/servlet/advanced?query=3359187