DEVELOPMENT OF EARLY WARNING SYSTEM FOR GEOTECHNICAL MULTI-HAZARDS INDUCED BY RAINFALL

抄録

Due to the global climate changes, the scale and frequency of natural disasters are more difficult to predict and measure. Extreme rainfall often brings astonishing amount of water and causes very serious damage in the mountain areas. For instances, during typhoon Morakot in 2009, many roadways and bridges were destroyed by the rainfall in south Taiwan; furthermore, the typhoon Megi brought amazing hourly rainfall to damage the Highway No.9 in I-lan County at 2010. Facing the challenges from the extreme weather conditions, the development of an early warning system has become a critical issue. Therefore, in the proposed study, the authors collected the field data of landslides and debris flows in No.18 Highway of middle Taiwan. And the authors collected the rainfall records of typhoons and storms from 2008 to 2012. Pattern recognition analysis was conducted to identify typical precipitation patterns that would cause slope failures and related debris flows. Threshold rainfall intensities and rainfall amounts that would possibly trigger the failures were chosen as two indices and their applicability based on different theoretical or empirical approaches from the selected precipitation patterns. Correlation between triggering rainfall indices and occurrences of landslides is to be established through this analysis.