RECENT ADVANCES IN ACQUISITION AND ANALYSIS OF SEISMIC, GPR, AND ELECTRICAL RESISTIVITY DATA FOR HYDROGEOPHYSICAL INVESTIGATIONS

The relatively recent appearance of the term "hydrogeophysics" corresponds with a growing awareness by policy makers on the importance of integrating geophysics and hydrology in groundwater resource management. Workers in research labs, industry, and academe have of course been working in this field long before the arrival of the new label. However, as a result of this growing interest--and important previous work--on the fusion of the two fields, a paradigm shift is occurring in which geophysical data is no longer used strictly as supplemental qualitative information for groundwater models, but rather is a critical quantitative constraint for understanding these complex systems. Several recent advances of techniques in near-surface geophysics as applied to hydrologic problems will be presented. These will include studies of fracture-related flow anisotropy using seismic refraction tomography, rapid azimuthal electrical resistivity analysis, and dense 3D GPR volume visualizations as well as an innovative method for target discrimination (e.g., NAPL identification) using amplitude variation with offset analysis on GPR data.