A key issue facing the abovementioned studies is to address the
vague parametric-information represented as fuzzy sets, particularly
when they appear concurrently in the objective and the left- and
right-hand-side of the constraints. Since such vague information is
involved in the inputs, the associated outputs (i.e. optimal management
polices) should also be uncertain. Although robust programming
could an available tool, it fails to provide uncertain level of
the outputs. Possibility-based chance-constrained programming
(PCP) has been proven to be useful for addressing vague parametric-information
and offering satisfactory level of generated optimal
water management strategies (He et al., 2008). Nonetheless, Liu
and Liu (2002) suggested that credibility should be a more reasonable
indicator measuring fuzzy inequality (or fuzzy event) than possibility
and necessity, since it makes up both of their disadvantages.
Unfortunately, no previous effort was found using the concept of
credibility to solve optimal water management problems under
complex parametric vagueness.