Abstract
The development of the city occurs not only above ground but also underground. Underground infrastructure is especially vulnerable to flood damage, caused by extreme events and natural disasters, as it forms the lowest layer un the hierarchy of urban structure. However, despite the increasing importance of urban inundation analysis, the lack of availability of data regarding underground space restricted analysis in previous studies. In this study, we established three-dimensional GIS data of subways using records and drawings of construction, which can be used for underground infrastructure inundation analysis in urban areas. Utilizing this established three-dimensional subway GIS data, we modeled and analyzed the areas of subway stations and train lines to be inundated by the projected Nankai Trough Earthquake. 82% of Nagoya city's Meiko Line close to the coastal area is expected to be submerged by an over 1m-deep flooding, and tsunami run-up through the train line is estimated to occur.