8.3. Groundwater Quality Management Models
287
8.3.4 Conjunctive U se and Basin Water Resources Planning
For a developing arid and semi-arid basin, water resources planning problem
is a major concern. Since local groundwater cannot satisfy the growing water
demand, conjunctive use of groundwater, surface water, imported water and
reclaimed water must be considered. To find the optimal water resources
management decision thus becomes a very challenging topic. For this kind
of management problem, decision variables may include:
• Extraction locations and rates in different years and seasons;
• Recharge locations and rates in different years and seasons;
• Amounts of imported water from different sources in different years and
seasons;
• Amounts of using reclaimed water in different years and seasons;
• Amounts of using and recharging surface water bodies in different years
and seasons.
Constraints may include:
• Groundwater level and quality constraints;
• Imported water quantity and quality constraints;
• Reclaimed water quantity and quality constraints;
• Surface water quantity and quality constraints;
• Physical constraints (capacities of wells and pipe lines).
Management objectives may include:
• Minimizing the total operation cost;
• Maximizing the quantity of supply water for basin development;
• Maintaining or improving the quality of supply water;
• Protecting the basin groundwater.
Obviously, there are conflicts among these objectives. It is impossible to
achieve them simultaneously. We can only find a compromise solution based
on the multiobjective decision making theory (Chankong and Haimes, 1983).
Yeh et al. (1992) accomplished a multiobjective water resources management
model for the upper Santa Ana basins, Southern California. In this project,
minimizing the total operation cost, minimizing the total mass of TDS
and minimizing the total mass of nitrogen were considered as management
objectives. An integrated pro gram was developed which included a twodimensional groundwater flow and mass transport model for the saturated
zone, a flow and mass transport model for the unsaturated zone, a river flow
and mass transport model, a planning model and a non-linear programming model. The planning model was used to form objective functions, set
constraints, and generate trade-off relations for any pairs of objectives.
In Yeh et al. (1995), a similar basin water resources planning problem was
considered for the Hemet basin, Riverside, California. The purpose of this
project was to answer if existing data in the basin was sufficient for construct-
287
8.3.4 Conjunctive U se and Basin Water Resources Planning
For a developing arid and semi-arid basin, water resources planning problem
is a major concern. Since local groundwater cannot satisfy the growing water
demand, conjunctive use of groundwater, surface water, imported water and
reclaimed water must be considered. To find the optimal water resources
management decision thus becomes a very challenging topic. For this kind
of management problem, decision variables may include:
• Extraction locations and rates in different years and seasons;
• Recharge locations and rates in different years and seasons;
• Amounts of imported water from different sources in different years and
seasons;
• Amounts of using reclaimed water in different years and seasons;
• Amounts of using and recharging surface water bodies in different years
and seasons.
Constraints may include:
• Groundwater level and quality constraints;
• Imported water quantity and quality constraints;
• Reclaimed water quantity and quality constraints;
• Surface water quantity and quality constraints;
• Physical constraints (capacities of wells and pipe lines).
Management objectives may include:
• Minimizing the total operation cost;
• Maximizing the quantity of supply water for basin development;
• Maintaining or improving the quality of supply water;
• Protecting the basin groundwater.
Obviously, there are conflicts among these objectives. It is impossible to
achieve them simultaneously. We can only find a compromise solution based
on the multiobjective decision making theory (Chankong and Haimes, 1983).
Yeh et al. (1992) accomplished a multiobjective water resources management
model for the upper Santa Ana basins, Southern California. In this project,
minimizing the total operation cost, minimizing the total mass of TDS
and minimizing the total mass of nitrogen were considered as management
objectives. An integrated pro gram was developed which included a twodimensional groundwater flow and mass transport model for the saturated
zone, a flow and mass transport model for the unsaturated zone, a river flow
and mass transport model, a planning model and a non-linear programming model. The planning model was used to form objective functions, set
constraints, and generate trade-off relations for any pairs of objectives.
In Yeh et al. (1995), a similar basin water resources planning problem was
considered for the Hemet basin, Riverside, California. The purpose of this
project was to answer if existing data in the basin was sufficient for construct-