A PROPOSAL OF THE METHOD FOR PREDICTING RIVER TSUNAMI RUN-UP AND FLOODING IN THE KUSHIRO CITY AREA AND ITS APPLICATION

Abstract

 This report aims to develop a disaster reduction method around rivers for supporting local governments and river administrators. The target basin is Kushiro City, where densely populated in lower altitude areas. First, we simply modeled series of tsunami run-up into rivers from a wave source region and tsunami inundation around the city. With varying river hydraulic parameters and tsunami source determined by reference to the actual tsunami event, the authors investigated tsunami external force on river facilities. Next, analyses were performed on the external forces on water supply and sewerage systems of the target city using maximum class tsunami wave data made public by Hokkaido government. As a result, depending on the conditions in river discharge, scale of the tsunami, elevation change on the ground, the variations of the disaster potential of these facilities were confirmed. The disaster mitigation proposal shown here can help local governments and river administrators to plan measures for tsunami run-up and inundation in emergency situations.