Risk Assessment of Storm Surge and River Flooding in Cities in the Bay Areas

在海湾地区广泛发展的城市群中，洪水灾害区划、风暴潮和河流洪水损失评估以及各种结构性和非结构性措施的有效性评估是灾害规划策略的重要组成部分。本研究的主要目的是提出风暴潮和河流洪水危险区域的预测方法。所提出的方法估计了风暴潮的发生和低洼保护区洪水的结果，已被证明对风暴潮对策的评估非常有用。利用该模拟模式可以预测21世纪以后由于温室效应引起的海平面上升的风暴潮洪涝风险区。如果海平面上升65厘米，大阪海湾地区将被严重淹没，这将是海平面上升前台风造成的洪水的2.5倍。如果海平面上升的预测是正确的，就必须对大阪湾地区的风暴潮采取新的对策。本文的仿真模型及其计算结果可作为此类对抗措施设计的依据。

In urban conglomerate cities extensively developed in bay area, flood-related hazard zoning, evaluation of losses due to storm surge and river flood, and evaluation of the effficacy of various structural and nonstructural measures are essential in planning strategy for hazares. This study mainly aims to present the method to predict the hazardous area due to storm surges and river floodings. Presented method, by which the occurrence of storm surges and the results of the flooding of protected low-lying areas are estimated, has been shown to be very useful for the assessment of countermeasures taken against storm surges. Zones at risk of storm surge flooding after the 21st century rise in sea level caused by the greenhouse effects could be predicted by this simulation model. A rise in sea level of 65cm would cause severe inundation in Osaka Bay Area about two and half times that flooded in a designed typhoon before the rise in sea level. If the predicted rise in sea level is valid, new countermeasures will have to be taken against storm surges in Osaka Bay area. Our simulation model and the results calculated from it can be used as the basis for the design of such countermeasures.