Development of an optimization model for water resources systemsplanning

A number of inexact fuzzy programming methods have been developed for the planning of water-resources-management systems under uncertainty. However, most of them do not allow the parameters in the objective and constraints of a programming problem to be functional intervals (i.e., the lower and upper bounds of the intervals are functions of impact factors). In this study, an interval fuzzy bi-infinite De Novo programming (IFBDP) method is developed in response to the above concern. A case study is also conducted; the solutions are then compared with those obtained from inexact De Novo programming (IDNP) and interval-fuzzy De Novo programming (IFDNP) that takes no account of bi-infinite programming. It is indicated that the IFBDP method can generate more reliable solutions with a lower risk of system failure due to the possible constraints violation and provide a more flexible management planning since the budgets availability can be adjusted with the variations in water price. These solutions are more flexible than those identified through IFDNP since the tolerance intervals are introduced to measure the level of constraints satisfaction. Moreover, it can be used for analyzing various scenarios that are associated with different levels of economic consequences under uncertainty.