A landslide dam breach induced debris flow - a case study on downstream hazard areas delineation

作者：Chen CY^*; Chen TC; Yu FC; Hung FY

来源：Environmental Geology, 2004, 47(1): 91-101.

• debris flow
• landslides
• Geographic Information System (GIS)
• landslide dam
• mapping
• Taiwan

A catastrophic landslide dam breach induced debris flow initiated in Da-Cu-Keng stream, Ruifang town, when typhoon Xangsane hit Taiwan on November 1, 2000. Different available methodologies were used to model the natural dam breach induced debris flow and using field topography the hazard zones affected by debris mixtures were delineated. The numerical finite element or finite difference method is time consuming for the simulation of debris flow inundation areas and hence a rules-based GIS (Geographic Information System) analysis is proposed in this study. The model emphasizes the downstream inundated fan-shaped areas covered by debris mixtures through the overflow point. Topography and gradient are assumed to dominate the debris masses deposition mechanism in the GIS analysis. The approach considers the parameters' effects, such as the runout distance, the debris masses magnitude and the inundated areas. The results of this study reveal that the GIS process using the rule-based approach speeds up the processing of delineating the hazard zones and assessment, which can be applied to early-warning and preliminary inundation hazardous mapping.

• 出版日期2004-12