Osaragi Risk Exposure Analysis for Weekdays and Weekends Estimation of Transient Occupants on Weekdays and Weekends for Risk Exposure Analysis Toshihiro Osaragi Tokyo Institute of Technology
[email protected] ABSTRACT Understanding the characteristics of the spatiotemporal distribution of a population, which varies according to the time of the day and the day of the week (weekday or weekend), is one of the most important issues in the field of urban disaster mitigation planning. However, the existing Person Trip Survey data based on weekdays is not appropriate for estimating the spatiotemporal distribution of population on weekends. In the present study, we proposed a method for converting existing Person Trip Survey data from a weekday base to a weekend base and examined the differences in the spatiotemporal distribution of the population. Using these databases, we attempted to compare the number of deaths due to building collapse estimated for weekdays and weekends for various districts in the Tokyo Metropolitan area. Keywords Risk exposure, weekday/weekend, spatiotemporal distribution, person trip survey, collapsed building. INTRODUCTION It is vital to have an accurate grasp of the constantly varying spatiotemporal distribution of transient occupants of the metropolitan region, including their ages, reasons for travel and other variables, in order to draw up detailed plans for disaster mitigation (Fukushima and Nakano, 1999). Until now, however, estimates of human casualties have relied on the static distribution of population provided by the national census and other counts (Osaragi and Hoshino, 2012). Thus, many recent-approved studies are based on a seismic intensity map, and only consider resident population from the census data (Smith, Martin and Cockings, 2014; Martin, Cockings and Leung, 2015).