SEGJ Technical Conference

Monitoring of rainfall penetration at slope areas using plural geophysical explorations - Estimation of the water content section by combining resistivity and surface wave surveys -

Abstract Slopes at risk of large-scale landslide in the future should be evaluated across the entire slopes for the behavior of groundwater infiltration from heavy rainfall. It is very important to establish monitoring techniques to visualize rainwater infiltration across entire slopes for the long term management of landslide risks. The authors have conducted a continuous resistivity survey over a period of several years at slope sites using the resistivity survey system for remote-controlled measurement in order to estimate rainwater infiltration from the 2D resistivity change sections. However, it is difficult to evaluate quantitatively the saturation rate change caused by rainwater infiltration using only resistivity data. Suzuki et al. (2018) have estimated the porosity and saturation rate sections by combining the S-wave velocity and resistivity based on the unconsolidated sand model (Avseth, 2005). In this paper, we demonstrate the application to monitor the saturation rate change in unsaturated zones caused by rainfall infiltration using both the resistivity and surface wave surveys data.