Proceedings of the Nineteenth (2009) International Offshore and Polar Engineering Conference Osaka, Japan
abstract:In this paper, we present a detailed study on the occurrence of regional debris flow hazards in storms after strong seismic disturbance. To explore the coupling between the Chi-Chi earthquake and sequential regional debris flow hazards in the study area, analyses of rainfall characteristics, rainfall-induced landslides, and debris flow formation from rainfall-induced landslides were conducted. Our findings indicate that the regional debris flow hazards were mainly caused by the huge amount of sparsely deposited materials from landslides triggered by the Chi-Chi earthquake. Rapidly increasing water pressure caused by typhoon events with specific rainfall intensity provided a powerful force that moved the sparsely deposited materials into gullies and then triggered the debris flow movement.