Risk Analysis Considering the Topography Characteristics of Debris Flow Occurrence Area

Abstract

Recently, debris flow has occurred so frequently due to abnormal heavy rainfall. Although various studies have been conducted to simulate the topographic behavior of debris flow, geometric effect such as the shapes of slope side has been insufficient. In this study, simulations were conducted with FLO-2D, the commercial software to be recommended by FEMA to simulate debris flow. And target geometries are selected as flatbed, square shape, trapezoidal shape and V-shape. Firstly FLO-2D was verified by the comparison with USGS debris flow experiments (Iverson, 2010). The comparisons showed good agreements in term of the velocity range and the propagation length of debris flows. Furthermore, the concept of HAZUS-HM risk analysis was used to assess the vulnerabilities of the structures by the impact of the debris flow. Simulated results were confirmed debris flow behavior to be changed due to the geometry type. Behavior of debris flows were analyzed according to the maximum depth, velocity, propagation length and vulnerabilities of the structures by the debris flow. This study would be practical to provide quantitatively the spatial distribution of hazard caused by debris flow.

The Movement Process of Typical Slope Debris Flow: A Case Study of Wujia Gully, Zengda, Sichuan Province China

“…In recent years, many studies on the kinematics characteristics of debris ow have been carried out, for example, by extracting topographic parameters (stream power index (SPI), topographic wetness index (TWI)) in the channels to study the movement characteristics or debris ow characteristics (Bhandari and Dhakal 2019; Chen and Lee 2010; Lee et al 2015;Tie 2014). The method of extracting topographical factors is mainly used in the hazard assessment of debris ow.…”

Comparative Analysis of Debris Flow Numerical Simulation Based on the Difference between the Resolution of Topographic Information and Grid Size

“…토석류를 모의하기 위한 수치모델 개발에 관한 연구 (Imran et al, 2001;Kim et al, 2018). 개발된 수치 모델의 시뮬레이션을 이용한 토석류의 위험도 평가에 관한 연구 (Liu et al, 2009;Lee et al, 2015;Wang et al, 2018), 수치해석을 위한 입력 변수의 적용에 관한 연구 (Hurlimann et al, 2008;Kang and Kim, 2017), 수치해석을 이용한 토석류 저감 시설물의 분석에 관한 연구 (Liu et al, 2013;Kim and Kim, 2021) et al, 1993).…”