Poster

[DE-P-01] Monitoring of rainfall infiltration on slopes by electrical resistivity and self-potential survey

*Kenji Kubota¹ (1. Central Research Institute of Electric Power Industry (CRIEPI) (Japan))

Hydropower facilities are generally located on slopes. If natural disasters due to localized torrential downpours cause a landslide, it may affect these facilities. Therefore, it is necessary to monitor rainfall infiltration on slopes to understand the locations where slope failures are likely to occur and detect the signs of landslides in advance. This study conducted electrical resistivity and self-potential (SP) surveys in a water sprinkling experiment along a slope to investigate the subsurface structure and change in water saturation in the subsurface. The test was conducted at the Central Research Institute of Electric Power Industry (CRIEPI) Akagi Testing Center, Gunma, Japan, where the soil contains a loamy layer. Water sprinkling was performed for 30 minutes. The total volume of water sprinkled was 242.6 mm, measured by a tipping-bucket rain gauge in the testing area. Electrical resistivity measurements were conducted before and after water sprinkling, and SP measurements were conducted every 2 s before and during water sprinkling. The electrical resistivity profiles demonstrated that the resistivity decreased after water sprinkling. The change in SP indicated that the SP decreased after water infiltrated the electrodes. These electrical resistivity changes can thus be used to detect groundwater infiltration areas while changes in SP can indicate water infiltration behavior.