Classification and evaluation of the documentary-recorded storm events in the Annals of the Choson Dynasty (1392-1910), Korea

In this study, the analysis of documentary records on the storm events in the Annals of the Choson Dynasty, covering the entire period of 519. years from 1392 to 1910, was carried out. By applying various key words related to storm events, a total of 556 documentary records could be identified. The main objective of this study was to develop rules of classification for the documentary records on the storm events in the Annals of the Choson Dynasty. The results were also compared with the rainfall data of the traditional Korean rain gauge, named Chukwooki, which are available from 1777 to 1910 (about 130. years). The analysis is organized as follows. First, the frequency of the documents, their length, comments about the size of the inundated area, the number of casualties, the number of property losses, and the size of the countermeasures, etc. were considered to determine the magnitude of the events. To this end, rules of classification of the storm events are developed. Cases in which the word 'disaster' was used along with detailed information about the casualties and property damages, were classified as high-level storm events. The high-level storm events were additionally sub-categorized into catastrophic, extreme, and severe events. Second, by applying the developed rules of classification, a total of 326 events were identified as high-level storm events during the 519. years of the Choson Dynasty. Among these high-level storm events, only 19 events were then classified as the catastrophic ones, 106 events as the extreme ones, and 201 events as the severe ones. The mean return period of these storm events was found to be about 30. years for the catastrophic events, 5. years for the extreme events, and 2-3. years for the severe events. Third, the classification results were verified considering the records of the traditional Korean rain gauge; it was found that the catastrophic events are strongly distinguished from other events with a mean total rainfall and a storm duration equal to 439.8. mm and 49.3. h, respectively. The return period of these catastrophic events was also estimated to be in the range 100-500. years.