A Case Study on the Closed-Type Barrier Effect on Debris Flows at Mt. Woomyeon, Korea in 2011 via a Numerical Approach

• Published in: Energies (Basel) Vol. 14; no. 23; p. 7890
• Main Authors: Choi, Shin-Kyu, Kwon, Tae-Hyuk
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.12.2021
• Subjects: barrier capacity; barrier location; Barriers; Behavior; Casualties; closed-type barrier; debris flow; Detritus; Elevation; Entrainment; Flow characteristics; Flow velocity; Fluid flow; Friction; Hazard mitigation; Hydrodynamics; Landslides & mudslides; Mitigation; Overflow; Rheology; Sea level; Simulation; Smooth particle hydrodynamics; System effectiveness; Velocity; Watersheds
• DOI: 10.3390/en14237890
• ISSN: 1996-1073

Debris flows are capable of flowing with high velocities and causing significant economic and infrastructural damage. As a hazard mitigation measure, physical barriers are frequently installed to dissipate the energy of debris flows. However, there is a lack of understanding on how barriers affect and interact with debris-flow behavior (e.g., velocity and volume). This study investigated the changes in debris-flow characteristics depending on the installation location of barriers. Mt. Woomyeon, which is located in Seoul, Korea, was the site of a major debris-flow event in 2011. This study modeled this event using DAN3D, numerical software based on smoothed particle hydrodynamics (SPH). Our numerical approach assessed changes in debris-flow behavior, including velocity and volume, as the debris flow interacts with four closed-type barriers installed at separate points along the flow path. We used DAN3D to model the barriers via terrain elevation modifications. The presence of a closed-type barrier results in the reduction in the debris-flow velocity and volume compared to when no barrier is present. Most notably, the closer a barrier is installed to the debris source, the greater the velocity decrease. By contrast, a barrier that is constructed further downstream allows the debris flow to undergo entrainment-driven growth before confronting the barrier, resulting in a larger debris deposition volume that can often cause overflow, as shown at our particular study site. The presented results highlight the effectiveness of barriers as a method of hazard mitigation by providing insight into how such installations can alter debris-flow behavior. In addition, the findings can provide a reference for future debris-flow barrier designs, increasing the effectiveness and efficiency of such barrier systems.