The rise in average sea level due to climate change aggravates the vulnerability of coastal areas, increasing the likelihood of flooding due to erosion of outfall to the coast and rivers. Therefore, the design standards of defense facilities should be strengthened to address such increased risk of flooding. Accordingly, in this study, a plan to adjust the disaster prevention performance target rainfall for two research areas was selected in consideration of the regional characteristics of the coastal area and the average sea level rise predicted for 2050, and the disaster prevention performance target rainfall increased from at least 89% to up to 169%. Based on these results, it is believed that this study can serve as a basis for improving data on rainfall targets for disaster prevention performance with consideration of future sea level rise in coastal cities.

Climate change caused by global warming is raising the average sea level. The rise in sea level leads to an increase in river water levels within the affected range, which increases the possibility of flooding in water due to erosion of outfall to the coast and rivers. Therefore, it is necessary to recognize in advance the risk of occurrence of domestic flooding, which is aggravated by the effect of rising sea levels, and to construct new boundary conditions for predicting urban flooding accordingly. In this study, Flood Nomograph for two research areas was selected in consideration of the regional characteristics of coastal areas and the scenario of sea level rise. As a result of the analysis, as the sea level rose, the amount of flood critical rainfall decreased numerically. It is believed that this study can be used as a necessary basis for improving flood forecast and warning data considering sea level rise in coastal cities in the future.