2016 年 22 巻 p. 303-308
Field investigations on Kuro River that is one of tributary of Omoi River were conducted. Nasahara area located in 15km of Kuro River was suffered severe flood damage for the 2015.09 Kanto-Tohoku heavy rainfall. Results of hearing to damaged inhabitants indicates that the first failure of river levee occurred at about 0:00 on the middle of the night of 9th. The process of the flood disaster after the first failure of the river levee was examined. Numerical analysis was also conducted to examine the process of the failures of the river levee. Results of the numerical analysis indicates that one of the river levee failure on the downstream side was caused by over-topping from landside to the river.