4.2. Network
Configuration
109
irrigated season. The net revenue per acre-foot of supplied water is $3.
Thus
MR n = 3(200,000) = $600,000
The available capital at the beginning of the planning period Oo was $2.8
million.
It was decided to limit the objectives of the proposed expansion to two
disparate facets of a water resources system: (1) a withdrawal-consumptive use and (2) a withdrawal-nonconsumptive use. A withdrawal-consumptive use of water implies that water is withdrawn from the system, is
consumed, and is not returned to the system. A withdrawal-nonconsumptive use of water implies that it is withdrawn and later returned to the
system, usually downstream from the withdrawal point. Irrigation was
chosen as the withdrawal consumptive use of water, since it is more consumptive than other uses; hydroelectric energy was chosen as the withdrawal nonconsumptive use because it is a function of power head and
water volume.
The other common purposes of water resources development, namely
municipal, industrial, and recreational use, are not incorporated explicitly
in this example. Municipal and industrial demands are satisfied only
through the specification of minimum flows in the adjacent river reaches,
while recreational needs are covered by the specification of minimum
seasonal water levels in the reservoirs.
4.2. Network Configuration
In the mathematical model, the year is divided into two periods (winter
and summer). Table 4.2 lists the upper (high = C m ) and lower (low ss L m )
flow capacities of each arc in the system and also the cost of passing one
unit of water through each arc (cost coefficient) of the system, as it exists
at the beginning of period 1. Note that all of these coefficients are integer
values because the OKA requires that all variables and costs be integer.
Also, the node numbers of Fig. 4.1 refer to the summer period. The winter
node numbers are obtained by adding 40 to every summer node number,
e.g., node 50 of the winter period corresponds to node 10 of the summer
period.
The unit irrigation and energy revenues (arcs 41-54 and 95-102) obtainable from the use of 1 acre-ft of water are similar to those applicable
in the Maule River Basin in Chile and in the Lewiston region of Idaho
[Bower, 1962; Wallace, 1966]. However, they are given negative values to
Configuration
109
irrigated season. The net revenue per acre-foot of supplied water is $3.
Thus
MR n = 3(200,000) = $600,000
The available capital at the beginning of the planning period Oo was $2.8
million.
It was decided to limit the objectives of the proposed expansion to two
disparate facets of a water resources system: (1) a withdrawal-consumptive use and (2) a withdrawal-nonconsumptive use. A withdrawal-consumptive use of water implies that water is withdrawn from the system, is
consumed, and is not returned to the system. A withdrawal-nonconsumptive use of water implies that it is withdrawn and later returned to the
system, usually downstream from the withdrawal point. Irrigation was
chosen as the withdrawal consumptive use of water, since it is more consumptive than other uses; hydroelectric energy was chosen as the withdrawal nonconsumptive use because it is a function of power head and
water volume.
The other common purposes of water resources development, namely
municipal, industrial, and recreational use, are not incorporated explicitly
in this example. Municipal and industrial demands are satisfied only
through the specification of minimum flows in the adjacent river reaches,
while recreational needs are covered by the specification of minimum
seasonal water levels in the reservoirs.
4.2. Network Configuration
In the mathematical model, the year is divided into two periods (winter
and summer). Table 4.2 lists the upper (high = C m ) and lower (low ss L m )
flow capacities of each arc in the system and also the cost of passing one
unit of water through each arc (cost coefficient) of the system, as it exists
at the beginning of period 1. Note that all of these coefficients are integer
values because the OKA requires that all variables and costs be integer.
Also, the node numbers of Fig. 4.1 refer to the summer period. The winter
node numbers are obtained by adding 40 to every summer node number,
e.g., node 50 of the winter period corresponds to node 10 of the summer
period.
The unit irrigation and energy revenues (arcs 41-54 and 95-102) obtainable from the use of 1 acre-ft of water are similar to those applicable
in the Maule River Basin in Chile and in the Lewiston region of Idaho
[Bower, 1962; Wallace, 1966]. However, they are given negative values to