Enhancing accuracy of slope stability analysis on coarse grid for wide-range applications

The frequency and scale of landslides have been increasing worldwide because of abnormal rainfall patterns induced by climate change. To prevent such disasters, numerous physical models have been developed. However, few studies have explored the application of these models to large watersheds. Therefore, to contribute to landslide damage mitigation in large-scale watersheds, we used coarse-resolution grids for application in large-scale watersheds, and slope a crucial factor in landslide analysis was utilized for the analysis using the TiVaSS (Time-Variant Slope Stability) model. This study simulated the landslide event of July 27, 2011 in the Mt. Umyeon watershed in the Republic of Korea using slope data with three different resolutions (10 m, 30 m, and 90 m). Receiver operating characteristic (ROC) and was applied to quantitatively analyze the performance of the TiVaSS using three different slope resolutions. The results show that TiVaSS performs favorably in landslide slope stability prediction. Additionally, using the slope extracted from the fine-resolution Digital Elevation Model as coarse-resolution grid leads to higher accuracy. Therefore, the landslide analysis using independent slope data proposed in this study was evaluated for effectiveness for large-scale watershed landslide analysis.