Abstract:
Porosity—one of the most basic mechanical
properties of a medium—has implications in a
vast range of disciplines and used for a similar vast
range of applications. These include, for instance, the
storage and flow of water; the compressible component
of earth materials, which can be subjected to
consolidation under loading; the variable parameter in
the swelling and shrinkage of clays; and possibly a
governing parameter in the formation of wetlands and
perched water tables. This review notes the relevance
of a fourfold quantification of porosity for vadose zone
studies, viz. (1) type (matrix or structure), (2) scale
(submicro to macro scale), (3) connectivity, and (4)
water saturation. This is followed by a review of recent
advances in the quantification and description of
porosity in porous media (visual and remote sensing
methods, porosimetry, geometrical approaches,
empirical estimations, densest packing simulations,
etc.), the applications to quantification of hydrological
parameters, and a brief glimpse into the significance of
porosity in a temporary hillslope wetland underlain by
Archaean Lanseria gneiss in South Africa. Final
comments are made regarding areas where quantification
of porosity is problematic.
