平成23年東北地方太平洋沖地震における津波浸水区域外の出火傾向の分析

摘要

Number of ignition that occurred outside of the tsunami-inundated areas following the 2011 Tohoku earthquake was analyzed using statistical models. For the analysis, the number of ignition, seismic data, and areal characteristics were surveyed for 698 municipalities in 17 prefectures of eastern Japan. The data set includes 191 earthquake-generated ignitions occurred within one month after the main shock. Regression analysis using Kawasumi model showed that there was no clear difference in the ignition probability between 1995 Kobe earthquake and 2011 Tohoku earthquake. Further analysis using GLM (Generalized Linear Model) showed that the JMA (Japan Meteorological Agency) seismic intensity, acceleration response with the period of 1.0s, and SI (Spectral Intensity) are the most appropriate explanatory parameters for evaluating the number of ignitions in each municipality. The proposed model could be used to predict the number of ignitions for future earthquakes.%本研究では，東北地方太平洋沖地震の発生から1ヶ月間の，東日本698市区町村の出火データを用いて，同地震による津波浸水区域外で発生した火災（地震関連火災）の出火傾向を分析した.まず，河角式を用いた分析では，同地震と兵庫県南部地震における地震関連火災の出火確率の比較を行い，両者に顕著な違いが見られないことを確認した.次に，ポアソン分布を誤差構造とする一般化線形モデルを適用することで，市区町村ごとの出火件数を予測するモデルを構築した.