Development of Multi-Layer Risk Assessment Criteria for Inland Flood Protection Facilities Based on Flood Case Analysis

This paper presents a multi-layered risk assessment criterion for quantitatively evaluating the flood risk of inland flood protection facilities by incorporating multiple variables, various time scales, and time-varying indicators. To overcome the limitations of single-indicator evaluations and incorporate complex flood characteristics into risk assessment, flood risk was quantified on a scale of 0 to 100, and the proposed criterion was validated using historical flood events. The results show that the extreme flood event on July 14, 2023, which resulted in casualties, was correctly identified as a high-risk case with a score of 63. No false negatives were observed, demonstrating the effectiveness of the proposed criterion in detecting critical flood situations. In addition, the water-level rise rate was identified as a key indicator for the early detection of rapidly developing floods. Specifically, a threshold of approximately 0.30 m/h was found to provide a practical basis for securing sufficient lead time (“golden time”) for proactive flood response. The proposed multi-layered risk assessment criterion overcome the limitations of conventional static and single-indicator approaches, and can serve as a practical decision support tool for real-time operation of flood protection facilities.