Reliability-Resiliency-Vulnerability Approach for Drought Analysis in South Korea Using 28 GCMs

This study developed a Reliability-Resiliency-Vulnerability (R-R-V) approach that aggregates the frequency, duration, and severity of droughts estimated using the Standardized Precipitation Evapotranspiration Index (SPEI). This approach was used to analyze the characteristics of droughts for the current (1976-2005) and the future (2010-2099) climates. The future climate data obtained from 28 general circulation models (GCMs) of Coupled Model Intercomparison Project Phase 5 (CMIP5) was divided into three general periods: Future 1: 2010-2039, Future 2: 2040-2069; and Future 3: 2070-2099. As a result, aggregation R-R-V representing water availability would increase during Future 1, and then gradually decrease until the end of the century. The frequencies of future drought events for Future 2 and Future 3 were similar to the current frequency, while the durations will be longer and the severity will be higher at most locations during Future 3. Thus, the mean of R-R-V over South Korea is expected to decrease, except for Future 1, and the spatial variability of R-R-V is expected to increase. In the end, the changes in the mean and variance of rainfall and temperature would lead to a decrease in the mean and increase in the spatial variation of sustainability in South Korea. This approach and its results can be used to establish a long-term drought strategy for regions where the risk of future drought is expected to increase.