One of the benefits of geophysical exploration is that extensive and continuous surveys are possible at low cost principally though elastic wave velocity and electrical resistivity. Therefore, the techniques that can derive quantitative information on the geological environment from geophysical data are essential for engineering applications. Various studies have been conducted to estimate hydraulic conductivity by combining several well logging data sets using rock physical models for sedimentary and crystalline rocks. In this study, the author calculated the hydraulic conductivity using the models for a soft sedimentary rock site and a granite site. As a result, the calculated values closely match the field and laboratory permeable tests using the rock samples. Next, the author have applied a quantitative analysis for porosity, clay content, and salinity profiles using a combined interpretation of multiple surface geophysical surveys data by using the extended bimodal mixture model. The S-wave velocity and resistivity data have been obtained at a soft sedimentary rock site, composed of the muddy or tuffaceous sandstone and mudstone. The results correlate with the salinities of pore water extracted from borehole core samples. It is expected that these techniques will be effective methods to investigate the shape of the interface of the fresh groundwater and salt water at coastal soft sedimentary rock sites.
