Abstract
This paper has tried to reveal the cause of irregular surge of water distribution volume and irregular decrease of water pressure respectively just after an earthquake. First the cause of a surge in water distribution volume is examined in a statistical manner based on the observation data by Osaka Waterworks Bureau (OWWB). Next the movement of water inflow into the water receiving tanks just after earthquakes are numerically examined using acceleration waveform collected by OWWB's earthquake monitoring system. The relationship between the sloshing phenomenon caused to water receiving tanks and a sudden surge of water distribution volumes was considered. Furthermore, the sloshing phenomenon of water in receiving tank was examined using hypothetical acceleration waveform of Tokai-Tonankai earthquake.
