Seismic Risk Assessment for Tokyo Bay Region by Geographic Information System

阪神-浅地震灾表明，单个震害现象之间复杂的相互作用可能对整个区域的震害产生强烈的综合影响。因此，我们提出了“经济活力”指标的概念来评价地震风险潜力。这是一个从两个角度预测地震破坏和灾害程度的评价指标，一个是对每个城市的微观评价，另一个是对整个地区的宏观评价。首先，我们用经验方法假定地震造成的破坏。然后，考虑到从全国人口普查、商业统计等得出的各种区域特征，我们评估了潜在损害对该地区的相互影响。提出了“经济活力”指数的概念和方法。该指数是通过比较正常情况下的经济活力和受灾情况下的经济活力，来评价受灾程度的指标。并以阪神湾地区阪神-淡路地震为例，进行了震害风险分析。其次，我们也试图在日本其他地区验证经济活力评价方法的一般有效性。特别是，我们建议根据评价方法对东京湾地区进行地震风险评价。具体来说，我们打算表明，我们可以通过评估地震发生时经济活力指数可能从正常水平下降的程度来评估地震风险。最后，我们试图将自己的地震风险评价与之前东京都根据常规评价方法所做的类似评价进行比较，从而证明我们的评价指标的独特有效性。

The Hanshin-Awaji Earthquake Disaster indicates that the complicated interaction of individual earthquake damage phenomena may have a strong overall impact on the region-wide damage. So we propose the concept of an "Economic Vitality" index in evaluating earthquake risk potential. This is an evaluation index with which to forecast earthquake damage and trouble degree from two viewpoints, one for a micro evaluation for each city ward, and the other for a region-wide macro evaluation.First, we presume damage from the quake by an empirical method. We then evaluate the interaction effects of damage on the region by potential, taking into account various regional characteristics derived from the national census, business statistics and so on. We propose to show the concept and method of "Economic Vitality" index. This index is designed to evaluate the degree of trouble by comparing the economic vitality in an ordinary circumstance and the lowered one in a disaster-stricken circumstance. We also make a case study regarding the seismic risk analysis of damage in the Hanshin-Awaji Earthquake for the Hanshin bay area.Secondary, we try to verify the general validity of the Economic Vitality evaluation method for other regions in Japan as well. In particular, we propose to make a seismic risk assessment for the Tokyo Bay region pursuant to the evaluation method. Specifically, we intend to show that we can evaluate a seismic risk by sizing up a possible decline in the Economic Vitality index from the normal level when an earthquake strikes. We finally try to compare our own seismic risk assessment with an earlier similar assessment made by Tokyo Metropolis pursuant to a conventional evaluation method, thereby testifying to the unique effectiveness of the evaluation index of ours.