Modeling an Incline Screening Ramp to Slow a Debris-Flow in a Post-Fire Environment Using HEC-RAS

Over the past few years, debris-flows are becoming greater threats to the environment and people in the path of these flows due to devastating wildfires within those areas and changes in the environment. Various barriers, and few mitigation structures, have been used to weaken or completely halt debris-flows, but debris-flow screens have rarely been researched or utilised against debris-flows. The purpose of this study is to improve the debris-flow screen by inclining its angle to withstand and slow the harsher debris-flows that come from post-fire environments. The hypothesis was that the inclined debris-flow screen would reduce the velocity and shear stress of the debris-flow by at least 20% more than if the debris-flow screen was not inclined at all. The study was conducted in HEC-RAS using the environment of Los Angeles County, California and generating a debris-flow simulated in a post-fire environment for the debris-flow screen to be tested on. The reference lines at the entrance of the catchment showed that the velocity decreased around 19.892% at 15 degrees and the shear stress remained the same for each angle due to how the debris-flow was simulated. Future studies can improve upon the methods used to simulate the debris-flow screen and utilize other countermeasures that receive little attention to work alongside barriers.