Fuzzy Logic in Multi-Objective Decision Making and Hydrological Modelling

Various tools are available for multiple criteria decision making, including multi-attribute utility theory, multi-objective mathematical programming, goal programming, and fuzzy set theory. Because fuzzy optimization can handle uncertainties present in management problems, the fuzzy set theory may offer a useful alternative method for solving these problems by incorporating expert opinions in decision making. This chapter starts with a brief description of fuzzy set theory. Next, it presents applications of fuzzy logic in hydrological modeling with special emphasis on snowmelt runoff modeling, followed by brief discussions of applications of fuzzy logic to flood forecasting and risk assessment of transboundary rivers. The chapter also presents case studies that demonstrate the capability of the fuzzy rule-based approach for successful modeling and forecasting of hydrological variables and optimal crop planning in the multi-objective system with conflicting objectives.