COMPUTATION OF URBAN INUNDATION CAUSED BY TYPHOON NO. 19, 2019 IN THE DOWNSTREAM BASIN OF THE TAMA RIVER

Abstract

 Typhoon No. 19 which occurred in October 2019 caused a lot of damage in wide range of Kanto region in Japan due to levee breaks, river floods, and urban inundation. As global climate change becomes more extreme, typhoons and localized torrential rain, which cannot be handled by the existing infrastructure currently, are increasing. This is no exception in any cities in Japan, and once unprecedented rain falls, river floods and urban inundation damage will occur. In this study, we used S-uiPS, which is a sophisticated inundation prediction method, to reproduce the inundation cases in the downstream area of the Tama River. For the input rainfall at that time, the XRAIN actual rainfall data of Typhoon No. 19 in 2019 is used. From this reproduction calculation, it is clarified that even if the amount of rainfall in the target area is small, if there is high-intensity rainfall upstream and the water level in the river rises, significant flooding may occur in the target area.