Evaluation on the Impact of Extreme Droughts in South Korea using the SPEI and RCP8.5 Climate Change Scenario

The Standardized Precipitation Index (SPI), a method widely used to analyze droughts related to climate change, does not consider variables related to temperature that it is limited in that it can`t consider changes in hydrological balance such as precipitation and evapotranspiration from climate change. If we were to consider only the future increase in precipitation from climate change, droughts may decrease. However, because usable water can diminish from an increase in evapotranspiration, it is indispensable to research to project droughts considering the amount of evapotranspiration as well as project and evaluate potential droughts considering the impact of climate change. As such, this study evaluated the occurrence of droughts using the Standardized Precipitation Evapotranspiration Index (SPEI) as a drought index of a new concept that is similar to SPI but includes the temperature variability. We extracted simulated future precipitation and temperature data(2011~2099) from the RCP climate change scenario of IPCC AR5 to evaluate the impact of future climate change on the occurrence of droughts of South Korea. We thus analyzed the ratio of evapotranspiration to precipitation of meteorological observatories nationwide. In addition, we calculated the SPEI in the process to evaluate the future occurrence of droughts of South Korea. As a result, the farther into the future, the more precipitation increased. But because of an increase in evapotranspiration also from a rise in temperature and continued dryness, the severity of droughts are forecast to exacerbate.