A Study of the Telluric Observations on the Processes of Slope Breakdowns

Narrow island of Taiwan is thickly peopled and its western plain is highly developed. Along with rapid growing in economy, unused hillsides are nowadays successively developed. Large amount of hillsides are exploited in the recent years, which damage the original conservation of soil and water in the hillsides of Taiwan. The rock types are sedimentary and metamorphic in the most of Taiwan mountain areas. Moreover, the mountain building in the active orogeny of Taiwan makes those areas highly fragile and unstable in the typhoon season during May to October when 78% of rainfall averagely happened. Thus, various magnitudes of landslide events are frequently occurred during summer and autumn seasons, causing numerous disasters. An important issue is the establishment of an early warning system for landslide occurrences in the hillsides for protecting the safety of life and belongings to the public. Landslide can be triggered by saturated pore fluid, which is absolutely one of relevant factors. Therefore, continuous real-time monitoring for the saturation of pore fluids becomes critical in the hillsides during rainy seasons. For reducing the landslide hazards, effectively monitoring their occurrences is eager to be prospected and completed in the future. This study is planning to build up a monitoring network of self-potential and geoelectrical resistivity in a high potential area of landslide, for example, the Taiping Mt., Ilan. The self-potential and geoelectrical resistivity monitoring is believed to be highly associated with the pore fluid saturation underground. Combining with other physical measurements available, such as pore pressure data, it would have the greatest improvement and understanding of landslide triggering mechanism and its early warning system.