Open AccessModeling the Relationship between Soil Bulk Density and the Hydraulic Conductivity Function
Author(s) -
Assouline S.
Publication year - 2006
Publication title -
vadose zone journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.036
H-Index - 81
ISSN - 1539-1663
DOI - 10.2136/vzj2005.0084
Subject(s) - hydraulic conductivity , soil water , bulk density , soil science , water retention curve , function (biology) , pedotransfer function , power function , conductivity , geotechnical engineering , soil gradation , environmental science , mathematics , geology , chemistry , mathematical analysis , evolutionary biology , biology
A model is presented that could quantify and predict the effect of an increase in soil bulk density on the hydraulic conductivity function (HCF). Two approaches are formulated to predict the saturated hydraulic conductivity of compacted soils. The first approach is a general expression based on the Kozeny equation that requires only information on the bulk density. The second approach exploits information contained in the water retention curve (WRC). This approach, which relies on Assouline's model for soil HCFs, also provides a basis for a proposed expression to predict the unsaturated HCF of compacted soils. It is shown that a relationship between η, the power parameter in the expression for the HCF, and ε, the coefficient of variation of the WRC, is applicable to a large number of both compacted and uncompacted soils. The model was verified against measured HCFs for soils at different bulk density values. Both the saturated and unsaturated hydraulic conductivities were well reproduced by the suggested expressions.