Review of Recent Progress in Predicting Gas Transport Parameters for Undisturbed Andisols : Campbell b Dependent Models for Gas Diffusivity and Air Permeability

Abstract

This paper reviews and connects recent studies on gas transport parameter models for Japanese volcanic ash soils (Andisols). Soil water retention from —1 kPa to —1.5 MPa of matric potential for differently-textured, undisturbed Andisols from three prefectures in Japan was well described by the simple Campbell(1974) model. Gas diffusivity in the same matric potential range was well predicted by two recent soil type (Campbell b) dependent models, while the classical Millington and Quirk (1961)model markedly under-predicted gas diffusivity for all Andisols. Air permeability (ka) in wet to medium moist soil (from —1 to —100 kPa of matric potential) was also well predicted by a Campbell b dependent model, provided that ka at —10 kPa of matric potential was measured and used as a reference point in the model. In conclusion, Campbell-based models appear highly useful for describing pore characteristics and predicting gaseous phase transport parameters in Andisols.