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A bimodal four-parameter lognormal linear model of soil water repellency persistence

✍ Scribed by C. M. Regalado; A. Ritter


Book ID
102863033
Publisher
John Wiley and Sons
Year
2009
Tongue
English
Weight
579 KB
Volume
23
Category
Article
ISSN
0885-6087

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✦ Synopsis


Abstract

Soil water repellency may be characterized in terms of the delayed infiltration time of a water droplet resting on the soil surface, which is, water drop penetration time (WDPT), or repellency persistence. Such repellency persistence varies nonlinearly with soil water content (θ~g~), although no models have been proposed to reproduce the variation of WDPT with θ~g~ in soils. Dynamic factor analysis (DFA) is used to identify two common patterns of unexplained variability in a scattered dataset of WDPT versus θ~g~ measurements. A four‐parameter lognormal distribution was fitted to both common patterns obtained by DFA, and these were combined additively in a weighted multiple linear bimodal model. We show how such an empirical model is capable of reproducing a large variety of WDPT versus θ~g~ curve shapes (N = 80) both within a wide range of measured WDPTs (0–17 000 s) and for samples with organic matter content ranging from 21·7 to 80·6 g (100 g)^−1^. Copyright © 2009 John Wiley & Sons, Ltd.