Relationships between porosity and hydraulic conductivity tend to
be strongly scale- and site-dependent and are thus very difficult
to establish. As a result, hydraulic conductivity distributions inferred
from geophysically derived porosity models must be calibrated using
some measurement of aquifer response. This type of calibration is
potentially very valuable as it may allow for transport predictions
within the considered hydrological unit at locations where only geophysical
measurements are available, thus reducing the number of well tests
required and thereby the costs of management and remediation. Here,
we explore this concept through a series of numerical experiments.
Considering the case of porosity characterization in saturated heterogeneous
aquifers using crosshole ground-penetrating radar and borehole porosity
log data, we use tracer test measurements to calibrate a relationship
between porosity and hydraulic conductivity that allows the best
prediction of the observed hydrological behavior. To examine the
validity and effectiveness of the obtained relationship, we examine
its performance at alternate locations not used in the calibration
procedure. Our results indicate that this methodology allows us to
obtain remarkably reliable hydrological predictions throughout the
considered hydrological unit based on the geophysical data only.
This was also found to be the case when significant uncertainty was
considered in the underlying relationship between porosity and hydraulic
conductivity.