산불 후 강우로 인한 토석류 재해 평가

Abstract

Wildfires denude vegetation on hillslopes, reduce soil permeability. and produce water-repellent soils that increase surface runoff. This process consequently increases soil erosion and soil movement during rains, and it makes burned areas more susceptible to debris flows. For appropriate debris flow mitigation strategies in burned areas, it should be prioritized to identify the areas with debris flow potential. This paper presents statistical models to estimate debris flow volumes in burned areas, based on existing data measured from the western United States Debris flow hazards was then mapped using the estimated volumes and probabilities of debris flows. The study area is located in California, U.S. where wildfires occurred in September 2014. Its debris flow hazards were assessed in response to three design rainfalls(2-, 10-, and 25-year recurrence intervals). To determine if statistical models can be applied to Korea, it is necessary to measure and compile data of post-fire debris flows. When the perimeters of burned areas are provided, debris flow hazards can be promptly mapped for making effective mitigation decision.