Disaster Reduction Measures Against Inundation in Underground Area and Development of Disaster Prevention Action Plan Using TimeLine

Abstract

Japan uses underground spaces more widely than in other developed countries. Underground spaces around terminal train stations and areas under station plazas are used in developing public pathways with stores. One such area, managed by a single underground city manager, has a floor area of about 80,000m2. In 1999, the Mikasa River near an underground area in front of Hakata Station flooded the underground area. The importance of antiflood measures for underground area was pointed out after the Hakata disaster and Japan’s Flood Control Act was partly amended, but measures have not been implemented satisfactorily. In this paper, the author reviews the current situation in Japan’s underground areas for flood disaster and based on the awareness surveys of underground managers and users, the researches on systemizing antiflood measures for underground areas and the applications of a disaster prevention action plan (TimeLine) for protecting persons from flooding are shown using an example of the underground shopping area in front of Nagoya Station as a case study.