This study was conducted to determine the effect of rainfall after cutting on nutritive value of Italian ryegrass (Lolium multiflorum) hay. Fresh Italian ryegrass was treated with 3 days natural rainfall (56.5, 14.0 and 1.6 mm) after cutting without tedding. Rainfall effect on Italian ryegrass quality was evaluated based on Neutral detergent fiber (NDF) and acid detergent fiber (ADF), crude protein (CP), crude fat (CF), crude ash (CA) and non-fiber carbohydrate (NFC). The quality of Italian ryegrass was decreased with extending raining days. The content of neutral detergent fiber (NDF) was increased from 0.4 to 4.7% by 1 day advancement in raining. CF content was decreased from 8.1 to 32.8%. CP and CA contents did not change, but NFC content was decreased from 0.5 to 8.4%. The quality damage by the number of raining days after cutting Italian ryegrass was the lowest on the first day from exposure to rain.

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 disaster caused by the heavy rain results in the greatest damage Among the damages caused by the weather disaster. many previous researches actively analyzed heavy rainfall disasters. The work includes analyzing vulnerability of disaster using characteristics and size of disaster damage in local area, selecting influencing factors influencing disaster and analyzing its influence. Rainfall during the heavy rainfall disaster is concerned with regional vulnerability to rainfall. The disaster-induced rainfall averaged on scale was analyzed by classifying disaster damage scale. The damage per precipitation unit is assumed to be disaster vulnerability, and local vulnerability of disasters is analyzed and the tendency of disaster vulnerability is analyzed using a time series analysis. The total amount of rainfall during the disaster period was analyzed in a large amount of rainfall in the Seoul metropolitan area and Busan city. The analysis shows that The average rainfall per accident case is high, and the region with relatively high stability against heavy rainfall disaster is Seoul metropolitan city. Southwest regions of the Korean Peninsula are analyzed to be affected by a very small amount of precipitation. The damage analysis shows that Busan Metropolitan City and the metropolitan area are relatively safe area against disaster. The analysis of disaster vulnerability based on the precipitation during the heavy rainfall disaster provides a clear classification of vulnerability by region.