Analysis of Vehicle Tracking Maps in Iwate Prefecture Following the 2011 Tohoku Earthquake

We calculated the usable distance of the main roads in the coastal area of Iwate prefecture following the 2011 Tohoku Earthquake. Calculations were based on a vehicle tracking map built from G-BOOK telematics data using QGIS, an open source geographic information system. The main findings are as follows. (1) The change in the accumulative usable road distance ratio during the research period differed by city. (2) The ratio increases in the usable distance of Kuji, Iwaizumi, and Noda were extremely delayed. We could determine related roads by analyzing the maps generated by QGIS software. For Kuji and Iwaizumi, delays were mostly dependent on Iwate Prefectural Road number 7 (Kuji-Iwaizumi line). For Noda, the delay was mostly dependent on Iwate Prefectural Road number 273 (Akka-Tamagawa line). (3) In our previous study, we determined that the use of the main road in the southern coastal area of Iwate prefecture was completely recovered by April 29, 2011. However, in this study, when we precisely observed the change in the usable road distance ratio during the research period for each city, the ratio increase in the usable distance of Kamaishi was delayed compared to other southern coastal cities.