In this study, we identified heavy rain damage and rainfall characteristics for each region, and proposed Hazard-Triggering rainfall according to heavy rain damage scale focused on Gyeonggi-do. We classified the damage scale into three groups (total damage, over 100 million won, over 1 billion won) to identify the characteristics of heavy rain damage, and we determined criteria of the rainfall class for each rainfall variable (maximum rainfalls for the durations of 1, 3, 6, 12 hours) to identify the rainfall characteristics. We calculated the cumulative probability of heavy rain damage based on the rain criteria mentioned above to establish the Hazard-Triggering rainfall according to the heavy rainfall damage scale. Using the results, we establish the Hazard-Triggering rainfall for each rain variable according to heavy rain damage. Finally, this study calculated the assessment indicator (F1-Score) for classification performance to test the performance of the Hazard-Triggering rainfall. As the results, the classification performance of the Hazard-Triggering rainfall which proposed in this study was 11%, 30%, 10% higher than the criteria by KMA (Korea Meteorological Administration).

The purpose of this study is to identify the factors related to the heavy rain damage and to identify effect of repair and improvement for irrigation facilities on heavy rain damages. The results of the analysis are as follows. First, the imbalance of precipitation became worse over time from using the coefficient of variation. Second, the analysis using Spearman correlation coefficient shows positive relationship between heavy rain damage amount and precipitation amount, and negative correlation between heavy rain damage amount and repair and improvement for irrigation facilities cost. Third, the analysis of the panel regression model shows that the negative impact of the repair and improvement for irrigation facilities cost on the heavy rain damage, which means that the increase of the repair and improvement for irrigation facilities cost can reduce the heavy rain damage.