Analysis of debris flow mitigation at ungauged watershed

The purpose of this study is to investigate the occurrence of debris flows, including their locations, volumes, and flow in regions. The field surveys were conducted in regions using a drone and a numerical analysis was performed with the RAMMS model to simulate debris flow behavior. The results of this study were compared with the actual debris flows. As a result of comparing the detailed map (Case A) and the actual debris flow occurrence status after the debris flow in the Docheon-ri basin in the model verification, it was confirmed that the spread area and movement distance were simulated to be the same, confirming the applicability of the model. As a result of simulating the digital map (Case B) before the occurrence of debris flow under the same conditions and comparing it with the actual debris flow occurrence status, the flow direction and spread shape of the debris flow were simulated to be similar except for the area that occurred beyond the basin. It was confirmed that simulation was possible. It is believed that it can be used as basic data for damage prevention, such as estimating the extent of damage from debris flow disasters, selecting on-site investigation points for expected debris flow damage, and evacuating residents within the debris flow damage area when heavy rain is expected.

Keywords: debris flow, heavy rain, RAMMS, survey, damage.