Development of Estimation Method for Loss of Human Lives Due to Catastrophic Urban Disasters

快速城市化增加了日本城市地区的灾害脆弱性。从坂神淡路大地震灾害中可以看出，在城市灾害中，有几种情况在灾害发生前是无法预测的，生命损失是极其巨大的。这主要是由于我们的城市社会结构复杂，如密集分布的木制和旧房子，在高峰时间每个铁路和地铁站都有大量拥挤的乘客，生命线网络系统冗余度很小。城市巨灾的特点是人口过多、能源和信息密集，与减灾防灾投资不平衡。大城市的人口密度超过100万，这是扩大生命损失和财产损失的最重要因素。生命的最大风险可以用寿命函数来估计，寿命函数表达了一种防灾力。用这种方法估算了1995年1月17日坂神淡路大地震造成的人员伤亡。据估计，最高死亡人数是科比、西宫和芦屋市记录人数的1.33倍。地震发生在凌晨5点46分，非常幸运，因为城市活动还没有开始。这场灾难给我们提供了许多关于损失情况的数据。从统计的角度来看，铁路事故中由于强地震加速度的地震所带来的人为损失几乎是最小的。

Rapid urbanization has increased disaster vulnerability in urban areas in Japan. As shown in the Great Hanshin-Awaji earthquake disasters, the loss of human lives are extremely huge in urban disasters in which several scenarios are not predictable before the disaster. This is mainly due to complex structure of our urban society such as densely distributed wooden and old houses, much crowded passengers at every railway and subway station in rush hours and lifeline network systems with a little redundancy. Catastrophic urban disasters are characterized by overpopulation and dense concetration of energy and information which have not maintained their balance with investment for disaster reduction or prevention. The population density in large cities of over 1 million residents is the most important factor which amplifies the loss of human lives as well as property damage. The maximum risk to life can be estimated with the function of lifespan which expresses a disaster prevention force. The loss of human lives due to the Great Hanshin-Awaji earthquake disaster in January 17,1995 was estimated by this method. The estimated maximum number of loss of lives was 1.33 times of the number recorded at Kobe, Nishinomiya and Ashiya cities. The earthquake occurrence at 5 : 46 am.was very fortunate because urban activity did not start yet. The disaster proposed us much data about scenarios of damage. From the view points of statistics, the railway accidents due to strong seismic acceleration of the earthquake brought almost minimum human damage.