  This paper proposes semi-analytical methods to obtain the local permeability
for granular soils based on indirect measurements of the local porosity profile
in a large coaxial cell permeameter using spatial time-domain reflectometry.
The porosity profile is used to obtain the local permeability using the
modified Kozeny-Carman and Katz-Thompson equations, which incorporated an
effective particle diameter that accounted for particle migration within the
permeameter. The profiles of the local permeability obtained from the proposed
methods are compared with experimentally obtained permeability distributions
using pressure measurements and flow rate. The permeabilities obtained with the
proposed methods are comparable with the experimentally obtained permeabilities
and are within one order of magnitude deviation, which is an acceptable range
for practical applications.
