Optimizing integrated water resources management: data, tools, and examples

Best utilizing water resources requires coordinating their availability and use in time and space. Required can be: spatially and temporally distributed data; simulators to predict system response to stimuli; procedures for defining management goals, constraints, and scenarios; optimizers to compute optimal management strategies; and appropriate strategy implementation techniques. Here, a strategy is a set of controllable groundwater extraction and injection rates and surface water diversions. Simulation/optimization (S/O) models couple simulators and optimizers to compute optimal strategies for posed management problems. S/O models are becoming more commonly used for policy, planning, system design, and management. For example, water planners and managers sometimes must decide how to control groundwater use to cause a favorable future and avoid serious problems. S/O models can help determine the policies, physical systems, and management strategies that can yield the best consequences. ‘Best’ is defined by the manager/modeler in terms of water availability, sustainability, crop production, economic, social, or environmental criteria, or combinations of those. Addressing multi-objective optimization problems and developing quantified tradeoff curves is simple with a powerful S/O model such as SOMOS. Examples demonstrate data needs and S/O model power for policy and plan development and system design and management.