Study of the Use of an Airborne Electromagnetic Method to Extract Data on Areas Likely to Cause Landslides

Abstract:

In recent years, there have been studies of the use of airborne electromagnetic methods to extract data on the areas likely to cause deep-seated catastrophic landslides or shallow landslides. In this data extraction, it is important to show the underground geological structures and hydrological conditions by using specific electrical resistance. However, there have been insufficient studies in this field. Therefore, in this study, we focused on areas in which deep-seated catastrophic landslides or shallow landslides had occurred in the past. We then used the distributions of specific electrical resistance to study the geological structure and hydrological conditions of areas likely to cause landslides.

First, in each study area, we tried to understand the geological planar distributions and the characteristics of the specific electrical resistance. Next, we tried to use the specific electrical resistance to understand the characteristics of the landslides areas. Last, we used the results to determine the geological distribution and hydrological condition of areas likely to cause deep-seated catastrophic landslides or shallow landslides.

We obtained the following results. In areas in which deep-seated catastrophic landslides had occurred, we found two distribution patterns of specific electrical resistance. In the first pattern, the specific electrical resistance changed suddenly around the face of the collapse. In the second pattern, the specific resistance was low overall in areas of high groundwater. In areas in which shallow landslides had occurred, we found that the contour of the specific electrical resistance was vertical and that groundwater was able to flow easily from the geologic boundary.