Inversions of an individual geophysical data set can be highly nonunique,
and it is generally difficult to determine petrophysical parameters
from geophysical data. We show that both issues can be addressed
by adopting a statistical multiparameter approach that requires the
acquisition, processing, and separate inversion of two or more types
of geophysical data. To combine information contained in the physical-property
models that result from inverting the individual data sets and to
estimate the spatial distribution of petrophysical parameters in
regions where they are known at only a few locations, we demonstrate
the potential of the fuzzy c -means (FCM) clustering technique. After
testing this new approach on synthetic data, we apply it to limited
crosshole georadar, crosshole seismic, gamma-log, and slug-test data
acquired within a shallow alluvial aquifer. The derived multiparameter
model effectively outlines the major sedimentary units observed in
numerous boreholes and provides plausible estimates for the spatial
distributions of gamma-ray emitters and hydraulic conductivity.