令和元年台風19号による利根川上流域の洪水外力の推定と治水課題の考察

抄録

Typhoon Hagibis caused heavy rainfall, widespread flooding, and serious damage mainly in eastern Japan. This disaster caused 140 levee breaks in 71 rivers and led the way of flood control planning in Japan to face some tough situations. Although, the Tone River, Tama River, and Arakawa River did not cause major damage, they are considered to have a remarkable flood impacts with some sections exceeding the planned high water level. Thus, it is important to understand the characteristics of the flood flow in large rivers caused by Typhoon Hagibis. In this study, we focused on the estimation of the flood discharge in the Tone River by performing the RRI model simulation. The simulation result shows the peak discharge at Yattajima where is a flood control reference point in the Tone river is nearly same to the target flow discharge in the current river improvement plan. Furthermore, we extracted some lessons on the flood controlling in the Tone River from Typhoon Hagibis.