THE STUDY OF FLOODING DISASTER IN SORACHI RIVER CAUSED BY THE HISTORY MAXIMUM FLOOD IN 2016, HOKKAIDO, JAPAN

Abstract

 In 2016, the history maximum flood caused two levee breaches and wide flooding situation in Sorachi River, Hokkaido, Japan. Numerical analysis showed that relatively high velocity (around 3 m/sec.) occured on the floodplain after the upstream levee breache happened and it flowed toward to the downstream levee breache area. The downstream levee breaches could work to drain the flooding water and then would reduce the disaster scale in this time. Comparing the numerical results with the past airial photograph, flooding flow traced the old chacnnel which had been hiden under the farmland field.