NUMERICAL SIMULATION OF INUNDATION ON ROADS AND IN UNDERGROUND SPACES IN HIGHLY URBANIZED AREA OF THE CENTER OF TOKYO

Abstract

Recently, we often experience a localized torrential rain whose intensity is much larger than the design value for drainage network system. Numerical simulation ofinundation was conducted in order to estimate how hazardous the highly urbanized area of center of Tokyo is if such a heavy rain attacks there. There are several underground spaces including subway stations there, and a number of gates for stairs toward the space exist in the spots where the ground elevation is lower than the surrounding area. As a result of this study, it was concluded that serious inundation may occur in large scale underground space in this area. We also found out the gates leading to the space through which water flowing on road can enter.