138
5. Sensitivity
of Planning Decisions in River Basin
Management
Demand profile
(DP)!
(DP),
Interest rate
Reservoir
Hydrology
costs
η
r 2
η
r 2
HYi
Rd
(9, 4)«
(6, 9)
(12, 10)
(9, 4)
(6, 9)
(12, 10)
(9, 3)
(12, 4)
(6, 10)
(9, 3)
(12, 5)
(6, 10)
RC2
(9, 4)
(6, 9)
(12, U)
Infeasible
(9, 4)
(12, 5)
(6, 11)
Infeasible
Rd
(9, 3)
(12, 4)
(6, 10)
(9, 2)
(12, 4)
(6, 10)
(9, 2)
(12, 4)
(6, 10)
(9, 2)
(12, 4)
(6, 10)
RC2
(9, 2)
(12, 4)
(6, 11)
Infeasible
(9, 2)
(12, 4)
(6, 11)
Infeasible
β
Group of three items signifies build dam 9 in year 4, dam 6 in year 9, and dam 12 in
year 10.
When both the interest rate and the reservoir costs were raised simultaneously, no solution was possible for scheduling the dam construction.
The lack of a feasible solution was caused by the fact that construction of
reservoirs 9 through 14 would not yield a positive net benefit even if the
reservoirs were operated at the highest efficiency over all their useful life.
For a real problem, if similar results occurred, the cost data for these
reservoirs should be scrutinized more closely before making any decisions
about reservoir construction.
In summary, this section points out the need for testing the sensitivity
of the outputs of a model to input and parameter variations before making
any final decisions, particularly in the construction of reservoirs that require large investments.
Table 5·3
Variation in Dam Construction Schedules with Different Combinations of
Inputs