Fuzzy VIKOR approach for assessing the vulnerability of the water supply to climate change and variability in South Korea

This study assessed the vulnerability of the water supply to climate change and variability in the South Korean provinces for the present and future with a fuzzy VIKOR approach. The key indicators of vulnerability were profiled with the Delphi surveys based on the IPCC-based vulnerability concept, in which vulnerability is defined as a function of sensitivity, adaptive capacity and climate exposure. The fuzzy VIKOR was used to aggregate the key indicators into a vulnerability score because it can provide a compromise solution considering overall satisfaction and regret of the selection of wrong provinces. Markedly different rankings between the fuzzy VIKOR and a conventional weighted sum for overall satisfactions suggest the importance of regret component of the selection of wrong provinces and inclusion of the uncertainty of information in the vulnerability assessment and consequent decision making for adaptation. Furthermore, diverse vulnerability rankings with the six different future scenarios suggest the need for robust decision making given such uncertainty.