Risk Assessment of Debris Flow at Regional Scale considering Catchment Area in Chuncheon, Korea

Abstract

In Korea, landslides and resulting debris flows occur frequently in summer due to typhoons and heavy rainfall. Furthermore, their volume and damage intensity have increased in recent years, and they have started occurring in urban areas. In this study, a regional debris flow risk assessment framework was developed and applied to the city of Chuncheon in South Korea. The initiation location and damage estimation area were identified by analyzing a digital elevation model of the area. Using the debris flow volume corrected by the catchment area, debris flow was simulated according to the rainfall return period. The vulnerability of buildings was estimated based on the debris flow simulation result. Finally, the quantitative risk of debris flows was assessed at regional scale. The study results can be used to establish a risk assessment method that considers the disaster risk and vulnerability of a structure upon which effective countermeasures can be devised.