Multiple Attribute Decision Making Methods For Reservoir Flood Control Operation

Multiple attribute decision making is a decision that can be used to choose the satisfactory scheme from determined schemes. Reservoir operation shows a very important practical significance. The article shows some discussions about multiple attribute decision making methods of reservoir risk operation, and it concludes the following aspects:(1) The inverse proportion of differences between the schemes and the grades and memberships of the schemes to grades are neglected. As data information can be reflected by entropy, and the flaws that great changes of entropy weight are induced by small changes of entropy, objective weights can be get by entropy weighs calculated from improved entropy method, organic combinations of objective weights and subjective weights(subjective target) are considered. Multilevel fuzzy optimization new model considering objective attribute and subjective preference is set up by the least square principle, the solution method is proposed and memberships and the most reasonable scheme are obtained. Take a flood dispatching of Hengren Reservoir as an example, the method is proved simple,practical and reasonable.(2) Based on the grey target theory in grey system theory, the variable weight was introduced into the approaching degree formula and the formula was improved in the model. The variable weight could be gotten by the objective weight combined with subjective weight. And the objective weight was obtained by improving the method of calculating objective weight of entropy, subjective weight could be gotten through the comparison between other attributes and the optimal attribute. So a new determination method was given. Taking one reservoir in Shanxi as an example, the objective weight was modified by given subjective weights in different periods, and then the optimum scheme could be determined through the comparisons of approaching degree of each scheme. The results obtained demonstrate that the grey target theory has obvious superiority, the method is simple, and can overcome the effects of some subjective factors in the traditional method, and is easy to be used.(3) Reservoir flood operation including quantitative indexes and qualitative indexes are a multiple attribute semi-structural decision-making problem. Aiming at the un-reasonability of qualitative indexes described by defining-numbers, interval numbers based on duality contrast and mood operator are proposed to describe the relative membership degree of qualitative indexes instead of defining-numbers. The relative membership degree matrix can be got by standardized values of quantitative indexes and qualitative indexes. For relative membership degree matrix, with the projection method, comparing the quotients of projection of interval ideal point and negative ideal point, the optimum scheme was chosen. Taken one flood dispatching of Sanmen Gorge Reservoir as example, the optimum scheme is obtained by the above method, which takes on affectivity and easy calculation.