The realities of water resource management demand that system operators balance multiple - often conflicting - objectives and operations. RiverWare's preemptive goal programming optimization mode provides a valuable tool for trading off multiple objectives. Both experts and nonexperts can employ this sophisticated optimization technique.

• Manage Multiple System Objectives

• Water supply
  
• Flood control
  
• Navigation
  
• Recreation
  
• Fish and wildlife habitat
  
• Hydropower production

RiverWare's Optimization Works Automatically

When an optimization run is made, RiverWare automatically generates the physical constraints such as mass balance, topological connections and upper/lower bounds from the constructed model. Enter prioritized policy objects and constraints through a graphical constraint editor, and they are automatically linearized. The linear program (LP) is generated for each goal and sent to a powerful, fast commercial solver. Objectives are met in order of priority, and the solution is returned to the objects.

The LP solver treats each successive constraint as an objective, finding the best solution and setting that solution as a constraint while meeting lower-priority objectives. The result: the best solution given the prioritized goals. The optimal values of the decision variables are then displayed in the slots. A post-optimization simulation run is automatically set up, the results of which provide an exact prediction of the basin's operation with the optimal reservoir releases.

Value-Added Features

• A multi-objective system can be solved without requiring "penalty matrices" or "objective weights" of conventional multi-objective optimization.
   
• The satisfaction of each objective is automatically distributed evenly over all reservoirs and all timesteps to avoid unacceptable solutions.
   
• The preferred linearization method for each variable can be selected, and the approximation points (e.g., for piecewise linearization) can be specified by the user.
   
• Objectives (goals) can be turned on and off or the priorities rearranged, through the graphical constraint editor.