A Study on the Estimation of the Occurrence Frequency of Mega-drought by the Characteristics of Drought Damage

Unlike natural disasters such as typhoons, torrential rains and floods, drought is a disaster caused by long-term effects as well as short-term effects. The effect of drought is caused by damage from a short period of weeks to a long period of years, which causes extensive and enormous damage to agriculture, life, society and economy. In addition, the recent climate change has affected the frequency and scale of rainfall in the global temperature, so it is necessary to prepare measures against it.

The past studies on drought have been conducted using drought indexes such as agricultural, meteorological, and hydrological methods to evaluate drought. The representative drought indexes for each drought are Palmer Drought Severity Index (PDSI), Standardized Precipitation Index (SPI), Agricultural drought is Crop Moisture Index (CMI), Crop Specific Drought Index (CSDI), Hydrological drought is Surface Drought Water Supply Index (SWSI), Reclamation Drought Index (RDI) and so on are used. However, these drought indices are only used as a method of predicting the depth of drought, and do not give the actual number of drought occurrences.

In this study, we want to determine the frequency of Mega-drought occurrences in consideration of the drought damage characteristics that occurred worldwide from 1900 to 2018. The drought damages in the world were used by EM-DAT (the Emergency Events Database) which manages disaster data in CRED (Centre for Research on the Epidemiology of Disasters). Drought damages occurred in the world from 1900 to 2018 occurred more than once/years in 146 countries. The duration of drought persistence occurred in the country continuously for at least one to 17 years. The purpose of this study is to propose the criteria for mega drought by using the past victim data in connection with the incidence frequency.

Acknowledges : This research was supported by a grant(2019-MOIS31-010) from Fundamental Technology Development Program for Extreme Disaster Response funded by Korean Ministry of Interior and Safety(MOIS).