Stepwise Decision Making Support Method for Water Use Systems Based on Multi-objective Optimized Alternatives

Abstract

Water use systems include stakeholders who have diverse preferences. Therefore, comprehensive assessment of various evaluation axes including environmental, economic and social aspects is required for planning water use systems. In addition, desirable systems are different depending on preferences when tradeoffs exist among evaluation axes. In this study, we applied Pareto improvement to multi-objective optimized solutions and obtained 71 alternatives of water uses systems. However, the number of the solutions is too large for stakeholders to choose an alternative. Hence, we proposed a two-step decision-making method. First, 71 solutions were divided into 8 groups by cluster analysis based on the values of objective functions such as costs and environmental impacts. Then, design variables of alternatives included in a selected cluster were presented. The proposed method can contribute to decision-making among stakeholders.