34
2.
Introduction
Even if an interest rate of 10% is used in the evaluation of public projects,
the chances are slim that many projects in the field of water resources development can pass an economic feasibility test.
1.5· Previous Work in Optimal Planning for a Water Resources
System
Most work that has been reported in the last two decades has been devoted to finding the best reservoir operating rules (refer to Section L3).
However, in the last few years some attention has been focused on finding
the optimal sizing and time of construction of system elements [Hufschmidt, 1962; Generoso, 1966; Wallace, 1966; McLaughlin, 1967; Howard
and Nemhauser, 1968; Butcher et al, 1969; Young et al> 1969; Woolsey,
1969; Weiss and Beard, 1970; Hinomoto, 1970; Morin, 1970; Nayak and
Arora, 1970]. Hall and Shepard [1967] used a combination of linear and dynamic programming to find the reservoir operating rules of a complex river
system comprising the rivers, canals, and dams of Northern California that
were part of the California Water Plan. Moseley et al [1969], Young et al.
[1970], and Evenson and Moseley [1970] examined the necessary dimensions and sequence of construction of reservoirs and canals for the Texas
Water Plan [Texas Water Development Board, 1968].
Orlob [1970] described the approach taken by the planners for the Texas
Water System. As shown in Fig. 1.1, there would be 18 reservoirs and more
than 500 miles of canals; in addition there would be pumping facilities to
raise the water from sea level to over 3000 ft elevation. When posed as a
planning problem, the problem stated in words is
Given: (1) the location of all the reservoirs, (2) the roots of the interconnecting canals, (3) schedules for the in-basin demand for each reservoir
and each major junction of the system, (4) the hydrology of supply for
each major storage element, (5) the cost of imported water, and (6) the
costs of construction, operation, and maintenance for all the elements;
Find: the least costly alternative system and schedule for its construction
to meet the specified demands to the year 2020 within the prescribed legal,
financial, contractual, and political constraints.
The group used a combination of linear programming, simulation, response surface methods, and perturbation analysis. Their approach was to
seek "near optimum" solutions rather than exact optima to overcome the
limits that existed on computation time and computer facilities.
2.
Introduction
Even if an interest rate of 10% is used in the evaluation of public projects,
the chances are slim that many projects in the field of water resources development can pass an economic feasibility test.
1.5· Previous Work in Optimal Planning for a Water Resources
System
Most work that has been reported in the last two decades has been devoted to finding the best reservoir operating rules (refer to Section L3).
However, in the last few years some attention has been focused on finding
the optimal sizing and time of construction of system elements [Hufschmidt, 1962; Generoso, 1966; Wallace, 1966; McLaughlin, 1967; Howard
and Nemhauser, 1968; Butcher et al, 1969; Young et al> 1969; Woolsey,
1969; Weiss and Beard, 1970; Hinomoto, 1970; Morin, 1970; Nayak and
Arora, 1970]. Hall and Shepard [1967] used a combination of linear and dynamic programming to find the reservoir operating rules of a complex river
system comprising the rivers, canals, and dams of Northern California that
were part of the California Water Plan. Moseley et al [1969], Young et al.
[1970], and Evenson and Moseley [1970] examined the necessary dimensions and sequence of construction of reservoirs and canals for the Texas
Water Plan [Texas Water Development Board, 1968].
Orlob [1970] described the approach taken by the planners for the Texas
Water System. As shown in Fig. 1.1, there would be 18 reservoirs and more
than 500 miles of canals; in addition there would be pumping facilities to
raise the water from sea level to over 3000 ft elevation. When posed as a
planning problem, the problem stated in words is
Given: (1) the location of all the reservoirs, (2) the roots of the interconnecting canals, (3) schedules for the in-basin demand for each reservoir
and each major junction of the system, (4) the hydrology of supply for
each major storage element, (5) the cost of imported water, and (6) the
costs of construction, operation, and maintenance for all the elements;
Find: the least costly alternative system and schedule for its construction
to meet the specified demands to the year 2020 within the prescribed legal,
financial, contractual, and political constraints.
The group used a combination of linear programming, simulation, response surface methods, and perturbation analysis. Their approach was to
seek "near optimum" solutions rather than exact optima to overcome the
limits that existed on computation time and computer facilities.