Development of an information system using GIS to protect cultural properties against disasters and investigation of cultural properties damaged by the Iwate – Miyagi Nairiku Earthquake in 2008
Since 2003, the National Research Institute for Cultural Properties, Tokyo has been engaged in a 5-year plan entitled “Disaster Prevention for Cultural Properties”. Included in the plan is the development of Disaster Prevention System for Cultural Properties (nationally designated cultural properties) based on a geographical information system (GIS). Several earthquakes have occurred in Japan since 2003 causing extensive damages. In 2008, also, an earthquake of magnitude 7.2 occurred around 8:43 a.m. on June 14, with its epicenter in southern Iwate prefecture (the Iwate – Miyagi Nairiku Earthquake in 2008). Many people fell victim to this earthquake, mainly due to landslides in mountainous areas. It also caused extensive damages to buildings and infrastructure. Damages induced by the earthquake to cultural properties designated by the national government have been reported at 30 locations in Iwate, Miyagi and Akita prefectures (according to investigation by the Agency for Cultural Affairs on August 20, 2008).
Immediately after the earthquake, the Institute used its Disaster Prevention System for Cultural Properties in order to identify areas strong motion areas by the earthquake and cultural properties designated by the national government (buildings) located in these areas (in the figure, areas framed in light blue experienced JMA seismic intensity of 5 lower or more, and light blue circles indicate cultural properties in these areas). It was later found that a relatively small number of buildings (9 out of 30) had suffered damages, mostly minor ones. However, since some damages were discovered in areas remote from those where possible damages had been predicted, it is believed that improvements should be made to the system, including those related to methods for prediction.
On July 31 and August 1, more than one month after the earthquake, an investigation was conducted of damaged cultural properties mainly in Miyagi prefecture. Among those properties that suffered severest damage is the stone fence of Nuruyu-Bansho in Hanayama village, which was built by the Sendai Clan and is designated as a historic site. Since the damage occurred at the same place which had been restored after heavy rain several years ago, it is hoped that the condition and cause of damage as well as past restorations would be investigated more in detail for future restoration work.