Development of Potential Map for Landslides Induced by the Chi-Chi Earthquake Using Instability Index

Abstract

In Taiwan, sloping lands cover more than 70% of the total area, and the geological condition of Taiwan is fairly fragile. The topography, geology, and tectonic setting make it highly prone to landslides induced by earthquake. In this research, data of the landslides triggered by the Chi-Chi Earthquake was analyzed for assessment of the potential and a predictive model was established for landslide occurrence of the area if similar earthquakes occur. Influence factors were selected and the instability index was used for assessing landslide potential. Through verification of an independent set of ground-based investigation data, results of the prediction model appeared to be satisfactory and can be used for mapping of landslide potential induced by similar earthquake in the future.