Accurate information is needed about the hydrogeologic properties
at the Department of Energy Hanford site in southeastern Washington.
This information is required in order to model the fate and transport
of subsurface contaminants. Ground penetrating radar (GPR) data were
collected in two areas at Hanford to assess the potential usefulness
of GPR for site characterization. The sediments at Hanford are such
that we found the penetration depth of the radar measurement to be
limited to approximately 10 m, in most locations, when using 100
MHz antennas. This means that GPR can only be used to obtain information
about the sediments in the top of the vadose zone. One survey objective
involved the use of GPR to locate clastic dikes, which can have a
large impact on contaminant transport. The dikes were clearly imaged
as diffraction hyperbolae in the GPR data. The second objective was
to test the use of GPR to describe the spatial variability in water
content.
Geostatistical analysis of GPR data from a test site yielded a correlation
length comparable to that obtained from analysis of neutron probe
data from the site. This result suggests that GPR data can be used
to quantify the subsurface distribution in water content at Hanford.