Analysis of factors prioritizing extreme weather countermeasures for aged agricultural fill-dams: Through statistical analysis of failure case histories

Abstract

Recent extreme weather, especially typhoons and heavy rainfall, has significantly increased the damage to the agricultural aged fill dams. Most agricultural reservoirs are the type of fill dams, and dam failures can cause uncontrollable, catastrophic damage to downstream areas. Therefore, establishing countermeasures to extreme weather events is crucial and urgent social problem. However, long-term forecasting of weather conditions is difficult, and recent extreme rainfall patterns are breaking records, making predicting dam failures even more challenging. Therefore, we analyzed recent failure cases to verify factors that can be identified as highly correlated to the damage of agricultural fill dams. The analysis, based on existing domestic and international research, examined the applicability of these factors using statistical methods, focusing on dam service life, dam height, total water reserve capacity, and the catchment magnification rate. Domestic and international data primarily considered dams service life of 50 years or more, an embankment height of 15 meters or less, and a total water reserve capacity of 200,000 tons or more. We collected a total of 87 cases between 2000 and 2024. As a result of the analysis, dam service life and embankment height showed similar trends to previous research results, suggesting applicability. However, total water reserve capacity showed some differences. Due to the high number of small dams in Korea, the failure rate was high even in small basins, suggesting no correlation between failure cases and the catchment magnification rate. The results presented in this study are expected to serve as important factors in prioritizing reinforcement measures for aged agricultural fill dams in the future.