2023 Volume 79 Issue 18 Article ID: 23-18168
In accordance with the revision of the Flood Prevention Law in 2015, prefectural governments are obliged to prepare maps of the expected inundation zones for the largest storm surges, and the "Guidance for Preparing Storm Surge Inundation Zone Maps" and "Technical Data" have been compiled to provide technical support. However, the guide does not include methods for calculating overtopping flow rates that take reef topography into account, or other analysis methods that reflect the unique characteristics of each region.In this study, we proposed a method that combines the "design depth formula" and the "Goda formula for estimating overtopping flow rate" as a simple method for calculating the overtopping flow rate on reef coasts. In addition, we quantitatively evaluated the necessity of mesh size setting to account for wave set-up and the effect of warm water eddies as considerations when validating the storm surge estimation model. As a result, we were able to appropriately evaluate a method that reflects regional characteristics for estimating the maximum expected storm surge along the coast of the Ryukyu Islands.
