PLANNING RESERVOIR OPERATIONS WITH IMPRECISE OBJECTIVES

Imprecise and noncommensurable objectives for reservoir operation are addressed through fuzzy dynamic programming using an implicit stochast ic approach. Fuzzy membership functions for evaluating the achievement of a linguistically described operational goal and linguistically des cribed constraints are estimated from surveys of decision makers, Summ ary statistics of the membership function values for optimal operation provide easily interpreted measures of degree of satisfaction among d iverse objectives. An example application to the proposed Grey Mountai n Reservoir on the Cache la Poudre River in northern Colorado showed t hat the expected degree of satisfaction for water supply objectives (c onstraints) would exceed 70% in six of 12 months, while 90% satisfacti on of the flood control objective could be expected throughout the yea r, Expected degrees of satisfaction for storage, recreational, fish ha bitat, and hydropower objectives are substantially lower, Relative var iability in predicted degrees of satisfaction is high. The average com posite degree of satisfaction for the project is moderate, has a gener al seasonal trend, and is substantially variable in late summer and ea rly fall.