Multi-scale accessibility performance of shelters types with diversity layout in coastal port cities: A case study in Nagoya City, Japan

Abstract

Abstract Besides facing threats from both earthquakes and tsunami, comprehensive coastal port cities have particularly high exposure and sensitivity to disaster risks. This study examined Nagoya City in Japan, one of the most advanced earthquake-tsunami hazard-resilient cities in the world. It first suggests that a diversity layout of seismic and tsunami shelters, which refers to they are laid out in a mixing and even situation, is an important targeted way for coastal port cities to respond to the earthquake-tsunami hazard risk. To estimate it, a Pearson correlation test was used to assess the relationship between shelter layout diversity and earthquake-tsunami risk. Next, it was studied the responsibilities coordination and distribution of each type of shelter with respect to a diversity layout, using an accessibility performance analysis. This was done because accessibility is key to a shelter s ability to fulfill its functional responsibilities; different responsibilities are associated with different accessibility requirements. Specifically, it was divided evacuation traffic patterns into three scale accessibilities, corresponding to three response stages in space-time evacuation routes during an earthquake-tsunami scenario. Then, changes in the accessibility performance for each shelter type, across different shelter layout diversity levels, were analyzed using a one-way Multivariate Analysis of Variance. Results show that some types of shelters adjust their responsibilities based on the scale of accessibility, due to closer cooperation with other types of shelters having a higher diversity layout. However, they may only maintain their baseline responsibilities without affecting by a higher diversity in other scales of accessibility.