Abstract
The purpose of this paper is to clarify the risk of storm surge and tsunami in Tokyo port by using three different numerical simulations, a storm surge simulation, a tsunami simulation and an overland inundation simulation. In the storm surge simulation, storm surge behavior in Tokyo port was calculated by considering many typhoon courses. The model typhoon used in the calculation is the Ise bay typhoon(1959), reproduced by using Myers equation. As a result, the maximum storm surge height in Tokyo port and the typhoon course which occurs are clarified. In the tsunami simulation, tsunami behavior in Tokyo bay is calculated under the consideration of three earthquakes. The target earthquakes are Genroku, Miura Peninsula and Kamogawa and Keicho earthquake. Amongst them, the earthquake which induces the highest tsunami in Tokyo port is the Keicho earthquake. In that case, the tsunami height around Tokyo port is about 1.5m. In the simulation, the initial tsunami heights were calculated by using the model of Manshinha and Smylie(1971). Overland inundation is simulated under the impact of the Keicho earthquake. The results show the western Koto Delta, Southern Koto Delta, East Shinagawa and many other areas outside Tokyo port are under the risk of inundation. For the overland inundation simulation, a 5m mesh topography data was used, which enables the display of micro scale inundation. The overall results show that it is necessary to reconsider disaster management plans in Tokyo, as current counter-measures might not be sufficient to protect certain areas against all foreseeable threats.
