Climate change has caused an increase in incidence of extreme weather such as floods and droughts. The Damages caused by the extreme events are not only limited to water. They also affect other sectors including agriculture, food, forestry, health and tourism, which are closely related to water. In addition to these disasters, it is plausible that the water supply may be interrupted by terrorist attacks or various human errors. If the water management system fails by those external forces, the functions of the society can be paralyzed and the irreversible economic damage may occur. In order to prevent the water-management crisis, it is necessary to be prepared for situations which has low probability of occurrence but may cause incalculable damage. Therefore, this study has aimed (1) to establish scenarios on the important water security crisis, (2) to analyse probability and impact of each scenario and (3) to draw management policies against the scenarios. Considered the spatial importance, the Han River watershed was selected as the study area. In particular, for analysis of the impact of floods and droughts caused by climate change, the regional climate scenario data produced from Representative Concentration Pathways (RCP) scenario and regional climate change model, HadGEM3-RA, were applied.

Authors investigated various factors which can result in water security crisis, e.g. natural disasters (such as floods, hurricanes, drought, climate change etc.), anthropogenic & technological accidents and drinking water contamination. Considering the definition of water security,