Development and Application of an Automated Check-Dam Scenario Analysis Program for Debris-Flow Hazards

Debris-flow hazards in mountainous watersheds are increasing due to more frequent and intense rainfall, and check dams are widely used to reduce these risks. However, mitigation performance varies depending on installation location and design conditions, necessitating a quantitative comparison of multiple alternatives. In this study, an automated scenario-analysis program was developed that integrates topographic data with a debris-flow numerical model to generate candidate check dam sites, construct installation scenarios, and evaluate mitigation effects. The program was applied to a 2019 debris-flow event in Gibuk-myeon, Pohang, South Korea. The results showed that mitigation effects varied substantially by dam location and height, and that the proposed framework can efficiently compare multiple alternatives, supporting practical check dam planning and design.