We developed the woody debris flood prediction system associated with debris-flow that contributes to highly precise hazard assessment and the formulation of effective countermeasures.

CTI Engineering Co., Ltd. has developed the woody debris flood prediction system associated with debris-flow that improves the precision with which the scope of woody debris floods due to debris flows can be predicted while also helping to plan effective woody debris countermeasure facilities.

　　

1. Challenges related to countermeasures in response to woody debris due to debris flows

In recent years, there has been increased damage as a result of woody debris flowing due to debris flows. Regarding woody debris flowing down slopes along with sediment--because the deposition, separation, and remigration processes are not well understood--it has been a challenge to devise suitable countermeasures in line with the actual woody debris situation.

　

2. Overview of the developed prediction system

In terms of modeling the woody debris flood and deposit situation, we focused on the fact that the sediment flow volume and woody debris flow volume due to debris flows at mountain streams are approximately proportional in order to develop a woody debris analysis model that can be used to manage the woody debris and sediment deposition and erosion process based on the woody debris concentration.

　

Based on a comparison with the results of an experiment conducted using the same conditions as when using our woody debris analysis model, we found that the woody debris analysis model we developed can be used to quantitatively track the woody debris movement scope and accumulation situation.

　

　

3. Future outlook

This technology could be utilized to perform higher precision assessment of hazard caused by woody debris disaster and plan effective countermeasure facilities, thereby helping to prevent or mitigate landslide disasters caused by debris flows. In addition, we will continue to accumulate knowledge and results through contracted business in order to expand the scope of utilization while also conducting research and development aimed at further precision improvements.

　

　　

　

　　

　

Results of comparing hydraulic-model-experiment and analysis-based reproduction calculations