A Study On Applicability Of Flood Risk Maps For Flood Risk Assessment

Existing qualitative evaluations for flood risks use the flood risk map made by applying extreme rainfall to national, local, and small rivers was used, so the submerged range is the same regardless of rainfall intensity. Therefore, this study prepares a flood risk map by frequency and conducted IBA (Indicator Based Approach) flood risk assessment from 2016 to 2020 for metropolitan cities. In addition, the future flood risk index reflecting the climate change scenario is calculated and the trend analysis is conducted by applying the Mann-Kendall method. This study individually prepares a flood risk map according to rainfall intensity by calculating the design flood discharge by frequency. In this case, not only hazard but also changes in the exposure and vulnerability indexes as the area of the flood risk map changes. In the case of exposure and vulnerability, the population and the number of buildings included in the flood risk map are extracted and calculated, so the index of the relevant items changes as the area of the flood risk map changes. This study conducts a future flood risk assessment using the climate change scenario when flood risks for future metropolitan cities can be analyzed and used to cope with environmental changes. In addition, if there is a trend to increase at specific rainfall observatories around metropolitan cities through trend analysis, it can be shown as evidence that the probability rainfall by future frequency is greatly calculated due to these characteristics. Using these results, a local government can make a plan to manage flood risk.