A geophysical characterization of a portion of American River levees in Sacramento, California was conducted in May 2007. Targets of interest included sand lenses that<br>underlay the levees and the depth to a clay unit that underlies the sand. The concern is that the erosion of these sand lenses can lead to levee failure in highly populated areas of<br>Sacramento. DC resistivity and electromagnetic surveys were conducted over a 6 mile length of the levee on roads and bicycle and horse trails. 2-D inversions were conducted<br>on all the geophysical data. The OhmMapper and SuperSting surveys produced consistent inversion results that characterized the targets of interest. GEM-2 apparent resistivity data were consistent with the DC inversion results. However, the GEM-2 data could not be inverted due to large system drifts. While this would not be as large a problem in conductive terrains, it is a problem for a small induction number electromagnetic profiling system such as the GEM-2 in a resistive terrain (the sand lenses). Despite issues with the GEM-2 inversion, this geophysical investigation was successful in detection of the sand lenses and the depth to the clay zone of interest.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error