Suggestion of heavy rain criteria based on the regional characteristics

Heavy rain advisory and warning are used in the Korea Meteorological Administration (KMA) to minimize the damage caused by heavy rainfall and to understand the intensity of heavy rainfall. Heavy rain advisory information is given to the public when the maximum rainfall exceeds 60 mm over a three-hour-duration, whereas heavy rain warning is given to the public when the maximum rainfall exceeds 60 mm over a three-hour-duration. However, these warning systems are all applied on the same basis, which causes a problem that regional characteristics are not reflected. In this study, we suggested a rainfall criterion which could cause disaster by considering local characteristics such as heavy rainfall. To do this, we define damage and hourly rainfall data using the Hazard-Triggering Rainfall. One to 24-hour-duration rainfall variables in a region is obtained and the variables are reduced to one principal component (PC) for analysis. We divided the data into groups based on a learning time period (2005 to 2013) and evaluation time period (2014 to 2017). As a result, the F1-score for the report of KMA was 46 percent and the Hazard-Triggering Rainfall was 57 percent. Therefore, Hazard-Triggering Rainfall may be more suitable for warning system. We also consider that the regional characteristics of damage and rainfall may need to include more properties of the region in future studies. From this study, we can use this result as a basis study for improving the criteria of heavy rain advisory and warning.

Keywords : Criteria for special weather report, F1-Score, Principal component analysis

Acknowledgment

This research was supported by a grant(MOIS-DP-2015-05) of Disaster Prediction and Mitigation Technology Development Program funded by Ministry of Interior and Safety(MOIS, Korea).