出水時の河岸浸食を伴う流路変動の発達要因

抄録

It is necessary to practice river works to protect dikes in consideration of channel change in a rapid river. However, the knowledge of the long term movement of channels and development of meandering with bank erosion is insufficient. Therefore, in this study, we focused on factors of channel change in a flooding rapid river in the case of the Otohuke River in 2011. Other than the flood of 2011, we added two more floods which caused dike erosion but varied in duration of flood time and shape of channel in order to expand our study.

In the consequence, we found that a channel greatly transformed itself and river bank erosion occurred if the channel meandered before flood or flood water gentry decreased the level. We note that for the purpose of decrease the risk of dike destruction, it is necessary to manage rivers with paying attention to not only the peak water level in a flood but also the decreasing water level after the peak.