Fuzzy optimal model for the flood control system of the upper and middle reaches of the Yangtze River

Based on the characteristics of the Yangtze River floods and the principles of fuzzy sets theory, a fuzzy optimal model has been established for the f lood system of the upper and middle reaches of this river. The system is di vided into three subsystems with specific flood control objectives. The Thr ee-Gorges Reservoir plays an important role in the system. A method for pro ducing flood operation alternatives of the Three-Gorges Reservoir is presen ted. Finally, the model is validated with three typical historical floods. The results show that the model is effective and flexible.