Climate change is a global stressor that can undermine water management policies developed with the assumption of stationary climate. While the response-surfacebased assessments provided a new paradigm for formulating actionable adaptive solutions, the uncertainty associated with the stress tests poses challenges. To address the risks of unsatisfactory performances in a climate domain, this study proposed the incorporation of the logistic regression into a decision-centric framework. The proposed approach replaces the "response surfaces" of the performance metrics typically used for the decision-scaling framework with the "logistic surfaces" that describes the risk of system failures against predefined performance thresholds. As a case study, water supply and environmental reliabilities were assessed within the eco-engineering decision-scaling framework for a complex river basin in South Korea. Results showed that humandemand-only operations in the river basin could result in the water deficiency at a location requiring environmental flows. To reduce the environmental risks, the stakeholders could accept increasing risks of unsatisfactory water supply performance at the sub-basins with small water demands. This study suggests that the logistic surfaces could provide a computational efficiency to measure system robustness to climatic changes from multiple perspectives together with the risk information for decision-making processes.

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Many regions has been facing formidable freshwater management and planning challenges. Concerns about limited water allocations, conservation of environmental and water qualities and policies for sustainable water use have been increased because rising water demand would cause water shortage in the near future. Therefore, it is necessary to look into possible alternative water resources management plans to mitigate the potential water shortage. However, it is not straightforward to predict and analyze the various situations likely to be occurred in the future. Also, finding an optimal solution among many alternatives to mitigate the water shortage is a complex task. In this study, a methodology of predicting and analyzing the water resources situations in the future using the K-WEAP (Korea Water Evaluation and Planning system) is presented and an optimal alternative is determined using the MCDA (Multi-Criteria Decision Analysis) that takes into account the economic, environmental, and social sectors. The proposed methodology is applied to the Nakdong River basin in South Korea to calculate water budget and possible water shortage. An optimal water shortage mitigation policy for the study basin is also suggested to help decision maker develop long-term water resources management strategies.

The main reasons behind the occurrence of floods are climate change and rapid urbanization. Floods bring heavy casualties and enormous property damage. Therefore, a lot of support and flood-defence policies should be implemented and indexes should be developed in an effort to figure out the flood vulnerability. This study will investigate and analyse these indexes and consider Korean regional features to develop an index suitable for Korea and estimate its flood vulnerability. For this purpose, 115 subbasins in Korea were selected, and data related to regional flood losses from 1990 to 2007 were investigated to establish a database of the floodrelated proxy variables for the period. In order to confirm the validity of the evaluation index, the results of Gangwon province from the calculated flood vulnerability assessment index (FVAI) are compared with actual flood damage records in 2008. Encouraged by this, FVAI was utilized as the means to estimate and present the regional flood vulnerability of Korea in the future. This study is expected to provide not only one of the various policy decision backgrounds, but also diversified information to better understand the current situation in Korea.

The purpose of this study is to understand the necessity for waterproofing and corrosion-resistant technique application on concrete water tank used in water supply. Relevant research materials and regulation were collected, reviewing for the case studies of sample structures aged over 20 years, and experimental studies on chloride conduction for the high performance concrete and penetration properties of water repellency of liquid type materials. The result is that the concrete water tank in the water supply is needed for waterproofing and corrosion-resistant material coating to maintain long term durability due to the constant environmentally induced degradation deterioration often caused by chloride attack.