A simulation model for reservoir operation based on
a given operation policy is combined with a GA for
optimization of rule curves to determine and evaluate
the performance of reservoir operation. In this study, the
chromosome length is equal to 24 genes for 12 months’
values of upper rule curves and 12 months’ values of
lower rule curves. Each gene represents the real value
of the Vupper and Vlower values of the rule curves. No
alleles or bits are considered in a gene, since real numbers
are used. The monthly releases, or state variables, are
determined based on the operation policy and the water
demand of each scenario. The value of the objective
function is improved by the GA until the maximum value
is obtained. A schematic diagram of the reservoir water
levels and the computational procedure of combined
simulation–GA approach are shown in Figures 7 and 8
respectively.